# Generator to direct-power EV for distance



## Tesseract (Sep 27, 2008)

Before you do anything else you need to determine just how much power you use driving at the expected speed, and maybe a little bit more... There's a huge difference in price (and size) between a 10kW and 25kW generator.

I would only consider propane or diesel powered units.

If you are really savvy you might be able to build your own with a small diesel engine (Kohler makes some that I have heard are pretty good) driving an induction generator but operating these beasts can be tricky. Still, your pack voltage is just right to simply rectify the output of the IG and apply it directly to the pack. IG's operate as a quasi constant current source and are totally safe from short circuits so they make great battery chargers.


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## Woodsmith (Jun 5, 2008)

If it were me I would be tempted to run a 240VAC generator to the Jeep and then convert to 144VDC.
The cables can then be a little smaller, with the higher voltage, and you will also have an AC generator for the times when you all stop and someone needs to do running repairs with some power tools.


Also depending on long you run and how long you coast or stop you may only need enough to keep the pack topped up.


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## DavidDymaxion (Dec 1, 2008)

You might be able to rent a powerful generator cheaper than buying or building something.


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## Jimdear2 (Oct 12, 2008)

Mike,

Good to see you back on the site. How is the Jeep performing? You should, by now know how many watts per mile the Jeep uses. From that you should have no problem figuring how big a generator set you will need.

Arn't there military generator trailers? Maybe you could find something surplus.

Rrectification of A/C is such a standardized thing that it will probably be the easiest part.

Another thought is one of those home emergency power generator sets mounted on a trailer of your own construction, you may even have one since you live out in the country. The come preconfigured for propane, a fuel you should be able to find with some frequency. Fuel use specs. for those gen sets is available so figuring storage on the trailer will be simple. I suppose that these sets are available with Diesel power as well.

Something that will run your home should run your Jeep with a little electronic wizardry added in. Either driveing through the batteries or directly. Myself I would try a through the battery system to even out the little ups and downs of power needs. 

I have heard of load sensitive gen sets, but that was just in passing 

Another way would be to rent one of those home APU units on a trailer. I've seen them advetised.

Just ramblin on,
Jim


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## m38mike (Dec 27, 2008)

Tesseract, you are right, I need to methodically evaluate my power needs. I'm thinking that I'll load one of my jeep trailers with about 500 lbs of something and start driving. I may set up a video camera to monitor my speed, amps, volts, rpm. I don't know about building an induction generator. The reference you gave showed making a small AC unit, but of course, I need DC. 

Woodsmith, I'm thinking along the same lines you are. One of my challenges is the equipment to convert 240VAC to 144VDC. I'm not sure what I need, and definitely do not know how to build it - but not afraid to try. I'm thinking that with a 144VDC rolling power pack, I'd make a great portable welder! 

David, I'm not sure the cost of renting wouldn't be more than the cost to buy a good used generator, by the time I get done testing, then spending 1-2 months on the road to Alaska and back.

Jimdear, Thanks, and the Jeep is running well - mostly. Still have a few circuit "challenges" that I'm playing with. To run this EV on a generator, I think I'm more concerned with my W/mph than W/mile. And I have not added the weight of a trailer to any of my tests so far. I need to do that to see what my total loaded weight will do to performance. 

I've been watching some surplus military diesel 10K gen sets and they are running about $2,000. Not bad if they are in good shape. I saw a generator trailer with a 15Kw sell for $4k. If I can make a 10k work, then I can simply load that into my military jeep trailer with room to spare. The military 10k is 2.5' x 2.5' x 4' and about 500 lbs. My trailer bed is 3.5' x 5.5', and it has a 900 lb capacity on road. So I'd also have room for tool boxes, and a 20 gallon aux fuel tank (mini-drum). And once I've completed this oddessy, I can take it on the road to EV conventions or car shows.

The military 10k is rated at 10k at 80% load, and is designed to operate at that load for up to 8 hours on one tank of diesel. The vehicle convoy I'd be part of has a typical speed of 40 mph and has a 10-15 minute stop every 1 to 1.5 hours. They plan to make about 2-300 miles per day with an 8 hour driving day. So what I'd be asking the gen to support should be well within the design requirements of a 10k, as long as I don't need more than that level of power on a sustained basis. For short bursts, or long hills, I could switch back to battery power. Once upon a while ago, I remember doing a rough calculation that told me that I could run my jeep at 60mph all day long using a 10k generator. But I don't think I calculated the weight of a trailer, generator, fuel, tools in that. I've got some experimenting to do.

I'd like to upgrade my Logi 1000 controller to a water cooled Netgain or Soliton. With this payload, and occasionally pulling long grades on the Alaska highway, I want a durable controller that can handle lots of heat. In fact I may want two, just in case. That part of British Columbia, the Yukon Territories, and central Alaska are not your typical EV communities. So replacement parts would be a long time coming on a little brown truck.


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## Bowser330 (Jun 15, 2008)

http://www.evconsultinginc.com/articles/hybridizing_dc_system.html

I dont know if that link helps, just trying to contribute and help...

Looks like you could keep your EV setup the same, no need for switching back in forth from genset current to battery current...

Per the link, you could just run the genset into your onboard charger(s) and have them charge the packs as normal..charging while discharging...

This may require you to upgrade your charger to something that can push more amps in your batteries. I am not sure if you can use dual chargers..all dpeends on what maximum charge amps your batteries can take...

I read online somewhere that this trek you are discussing is 4000 miles, is that true?


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## dragster (Sep 3, 2008)

Hi
You need a converter to take 240volts AC to 144 DC or what you are looking for in AC or DC.
The company is Yakawa
http://www.yaskawa.com/site/products.nsf/home/home.html
I got a 336 volt DC to 230 volts AC three ph for $260.00
The company will not sell you direct but will tell you what you need and direct you to a dealer close to you. Good luck


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## m38mike (Dec 27, 2008)

Thanks Bowser330, your link gave me a good lead to investigate. The EV consulting site recommended a Zivan NG5 charger as a good on board charger to take the 240VAC and feed the pack while the pack was powering the motor. I've got a Zivan 1500 charger, that uses 120VAC, I wonder if it is capable of continuous charging with the pack in use? I'll have to ask the manufacturer. I know that my 1500 will probably not be able to keep up with my power needs while on the move, but if it can come even close, then it may be able to catch up and top off the batteries while we're on breaks. That would also mean that I could probably get by with a slightly smaller generator - maybe a 5kW instead of a 10kW. That would save cost and weight. 

Does anyone out there know if a Zivan 1500 can charge while the pack is discharging? I didn't get a manual with my charger from the knuckleheads that installed it. Now I wish I had one.

I did a quick check of the mileage and it's about 2400 miles from Seattle to Anchorage. And the average convoy speed will only be 30 mph, not 40. And they expect to make between 100 and 200 miles per day. So it's slower and longer than I remembered. That works in my favor for finding a powerplant. That military 5kW is looking better and better, but I still need to do some experimenting with a loaded trailer to check my electrical loads. I don't think the WarP11 will have any problem pulling the load. I just need to be able to feed it enough power.


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## m38mike (Dec 27, 2008)

I've got another question, if i'm driving down the road at say 30 mph and the voltmeter reads 140v and the ammeter reads 120 amps, how would a Zivan NG5 144-30 possibly keep up with my power drain from the batteries? The Zivan takes in 240VAC and produces 144vdc at 30amps. It would seem to me that if I am using 120 amps, but only inputing 30 amps, then I'm not going to refill the pack at all, just extend my range by some small amount. 

What did I miss? or miscalculate?


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## Anaerin (Feb 4, 2009)

m38mike said:


> I've got another question, if i'm driving down the road at say 30 mph and the voltmeter reads 140v and the ammeter reads 120 amps, how would a Zivan NG5 144-30 possibly keep up with my power drain from the batteries? The Zivan takes in 240VAC and produces 144vdc at 30amps. It would seem to me that if I am using 120 amps, but only inputing 30 amps, then I'm not going to refill the pack at all, just extend my range by some small amount.
> 
> What did I miss? or miscalculate?


You didn't, and you're absolutely right. You will need to size your charger/generator to at least match, if not exceed, your driving load. But do bear in mind that while you are freewheeling, slowing, or stopped (IE, not loading the drive system) you will be charging your cells, thereby extending your range.

So, in other words, you size the Generator and Charger to meet your average load (to hold your vehicle at a certain speed, 55MPH for highway driving, for instance), letting the batteries soak up the excess during lean periods, and using the batteries to augment the generated power during heavy use periods.


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## Woodsmith (Jun 5, 2008)

m38mike said:


> I've got another question, if i'm driving down the road at say 30 mph and the voltmeter reads 140v and the ammeter reads 120 amps, how would a Zivan NG5 144-30 possibly keep up with my power drain from the batteries? The Zivan takes in 240VAC and produces 144vdc at 30amps. It would seem to me that if I am using 120 amps, but only inputing 30 amps, then I'm not going to refill the pack at all, just extend my range by some small amount.
> 
> What did I miss? or miscalculate?


It wouldn't if you were drawing that continuously. 
However, you may only be powering the motor part of the time, the rest of the time you are coasting on the level or down hill or to a stop. During these times the charger will be able to catch up a bit.

Also when you have stopped the charger can continue to charge if needed.


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## Overlander23 (Jun 15, 2009)

It means you're using 16,800 watts, or 22.4hp to maintain 30mph. That translates to 560 watt-hours per mile (16800/30=560)... which is kinda high for 30mph. So you need a generator that can output at least 16,800 watts to be able to continuously drive at 30mph. But your reading is an instantaneous measurement. If you take several measurements over a level mile and find yourself averaging the same numbers, then there you go. But 22.4hp @ 30mph does seem high to me.

And no, the Zivan would not be able to charge the cells at that rate. Max would be 144vdc x 30amps = 4320 watts from the charger.



m38mike said:


> I've got another question, if i'm driving down the road at say 30 mph and the voltmeter reads 140v and the ammeter reads 120 amps, how would a Zivan NG5 144-30 possibly keep up with my power drain from the batteries? The Zivan takes in 240VAC and produces 144vdc at 30amps. It would seem to me that if I am using 120 amps, but only inputing 30 amps, then I'm not going to refill the pack at all, just extend my range by some small amount.
> 
> What did I miss? or miscalculate?


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## JRP3 (Mar 7, 2008)

You need to figure your average amp draw. If you've normally using 120 amps at 30 mph that seems rather high. What's your normal max mileage from your pack?


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## m38mike (Dec 27, 2008)

Thanks everyone for helping me understand better the details I need to collect, and how to use them. I don't know that 120 amps at 30mph is my constant draw. I remember seeing that match up but I don't remember if I was climbing or on the level. Unfortunately where I live, not much is really level. And I still have not put a loaded trailer on back to see what a difference that would make. I did however find a trailer/generator combination that may work for me. Here's some photos.
























This is a jeep-size trailer with a 5kW generator on it. This would be a perfect match to the Zivan NG5 144-30 since it needs 4400w to provide a full 30 amps. And since it's all military, it fits in with the theme of the convoy. The combination gen/trlr weighs in at about 1500 lbs. That would put a tax on my power needs. It also makes me realize just how much more efficient today's hybrids are compared to the rugged military equipment I'm working with.


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## Tesseract (Sep 27, 2008)

m38mike said:


> ... I don't know about building an induction generator. The reference you gave showed making a small AC unit, but of course, I need DC.


S'alright, Mike. What I was basically saying is that the induction generator behaves a lot like a current source and since your pack voltage is 144VDC you could capacitively couple its output to a full-wave 3ph. rectifier to charge the batteries directly. Count on about 500-600W per nameplate hp of the original motor. So a 15hp induction motor should be good enough to produce 7.5kW to 9kW. 

A better link on how to use an induction motor as a generator is here.

Finally, you can also do the same thing with a regular generator: capacitively couple the output to a full-wave (or bridge) rectifier and charge the batteries directly. No charger needed. The coupling capacitors limit the current and the maximum voltage reached should the pack reach full charge (with 240VAC full wave rectified or 120VAC bridge rectified) is ~165VDC, or a nearly ideal 13.75VDC per 12V battery.


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## JRP3 (Mar 7, 2008)

For reference a 6kw propane generator from Northern Tools weighs around 200lbs I think. You can certainly do a much lighter genset trailer than that military unit.


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## Bottomfeeder (Jun 13, 2008)

Maybe you can solve the problem with something like this:

http://www.jstraubel.com/EVpusher/EVpusher2.htm


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## Aelwero (Aug 24, 2010)

Bottomfeeder said:


> Maybe you can solve the problem with something like this:
> 
> http://www.jstraubel.com/EVpusher/EVpusher2.htm



A trailer pushing a car sounds ridiculous, and dangerous, and unreasonable... 

I love it  

aesthetically speaking I think your better off with that 5K though... 
would it run biodiesel stock? I know they can run commercial diesel, so it seems like it should, but they are built to run JP8...


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## Woodsmith (Jun 5, 2008)

Aelwero said:


> A trailer pushing a car sounds ridiculous, and dangerous, and unreasonable...
> 
> I love it


That's why they are not legal in the UK.




Aelwero said:


> aesthetically speaking I think your better off with that 5K though...
> would it run biodiesel stock? I know they can run commercial diesel, so it seems like it should, but they are built to run JP8...


For a military Jeep a military trailer has to be the one to go for.
It would look authentic and quite reasonable to be towed along in the convoy.
I think a big red or yellow painted civvy gen set with Honda on the side would look wrong.


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## m38mike (Dec 27, 2008)

JRP3 has a good point, and one I need to consider if the trailer weight will become an significant issue with my power usage. I do have a regular army jeep trailer that I could put a commercial-style 6kW diesel gen in. With a coat of paint, and some appropriate stencilling I can make almost any generator look GI. And that would save me hundreds of pounds in weight. 

One point in favor of an actual military generator is their design and durability. They are designed to operate on the move. And they are built robust enough to take the beating of driving hundreds of miles on gravel roads. I'm not sure if I tried this with a commercial generator that it would stand up to the abuse of bouncing along a gravel road while spitting out power at a steady 70% load. 

The pusher-trailer idea is clever, but I just don't think I'm going there for this project. 

For my next out-loud thought, I need to figure out my driving duration from a fully charged pack to a 70% discharged pack. The batteries I currently have are Deka GC8V lead acid wet cells. They are rated at 165ah for 20h. They don't have a 5h rating. I have 18 of them to give me a design voltage of 144vdc. I have to go look up the Peukert's exponent for them. I don't remember it. That should give me 2,970ah (20h) for the pack before Peukert's. That equals 23,760w potential energy, minus 30% (7128) equals 16,632ah available to use. If I'm using 120w to maintain 30mph, then I'm using 17,000w per hour. This tells me that I could operate for about one hour at 30mph just from the batteries (ignoring peukert's ex for now). So if I had a 5kW feeding a Zivan NG5 and putting 30 amps back into the pack, it looks like I could drive for one hour, but I'd have to park for 3 hours to get back to a full charge before moving out again. 

I hope my actual use at 30mph is closer to 50w than 120w.


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## m38mike (Dec 27, 2008)

Has anyone tried using two chargers concurrently to charge a lead-acid battery pack? One of my thoughts was to run a pair of Zivan NG5 chargers off a 10kW generator. But I have no idea what the two chargers would do if they were both connected to the pack and charging at the same time. My initial thought is that they should both function normally. They would each see the pack voltage drop, and amperage get used, and begin to charge the pack. If they are programed the same, then they should both shut down at about the same time when the pack is full. 

This is another look at options for keeping the pack charged while travelling.


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## rillip3 (Jun 19, 2009)

m38mike said:


> Has anyone tried using two chargers concurrently to charge a lead-acid battery pack? One of my thoughts was to run a pair of Zivan NG5 chargers off a 10kW generator. But I have no idea what the two chargers would do if they were both connected to the pack and charging at the same time. My initial thought is that they should both function normally. They would each see the pack voltage drop, and amperage get used, and begin to charge the pack. If they are programed the same, then they should both shut down at about the same time when the pack is full.
> 
> This is another look at options for keeping the pack charged while travelling.


Using two chargers would be a very bad idea. Take a single battery example. It's made to charge at ~15 v. You put two chargers on it, and you're charging it at ~30v, even in the best case scenario. Internal resistance will make it heat up and burst. In the worst case scenario, the two chargers wouldn't just be dumping energy into the battery, but could start doing something to each other that I can't even understand. Possibly the universe could end. Seriously though, even if it works like you propose, it's a supreme fire and leakage hazard.


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## JRP3 (Mar 7, 2008)

rillip3 said:


> Using two chargers would be a very bad idea. Take a single battery example. It's made to charge at ~15 v. You put two chargers on it, and you're charging it at ~30v, even in the best case scenario.


Not if they are wired in parallel.


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## speedboats (Jan 10, 2009)

Totally off the shelf and out of the box... But WWII led to the birth of the jet age. Your Jeep is 1951? Jet age is with us by then. Why not use a minature jet motor to run a generator? Jet motor is lightweight, runs on all types of fuel (diesel, propane, alcohol, kero, etc), heaviest part would be the gearbox and gen-set. Coupled with a BMS you could see the battery pack need power and have the generator start to charge. With the fact that you intend to stop every 1.5hrs, this would allow time for the generator to catch up. If the gen-set was set up in parrallel then it could both drive the vehicle and charge the batt's at the same time. Just need to give some thought to sound insulation. Build a trailer to house the whole unit, paint it in 'you-can't-see-me' green, string some canvas over it and it won't look out of place.


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## JRP3 (Mar 7, 2008)

The high RPMS might be difficult to deal with, and wouldn't it use a lot of fuel?


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## rillip3 (Jun 19, 2009)

JRP3 said:


> Not if they are wired in parallel.


Okay, but if the total from both chargers is 15v, then you're charging at double the amps, and almost certainly charging it way over it's C rating for charging, which would have the same effect wouldn't it?


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## m38mike (Dec 27, 2008)

OK, so if they are wired in parrallel, as JRP3 suggests, then I'm getting my 144v at 60 amps instead of 288v at 30amps. So far that's good. But then rillip3 brings up a very good point. I'm trying to shove 60amps into batteries that boil if they get 30 or 40 amps. The jeep would smell like an acid factory, and I'd be pouring water into the cells at every stop. Not to mention the abuse the plates would be taking - if they could even take that much power. 

Granted, some of this is speculation, but based on some experience. This drives me back toward my first idea. Keep the generator and the batteries isolated, and run the jeep with the generator for long movements, during stops and down time, keep the on board charger plugged into the generator to gently charge the pack. Use the pack for times when I need extra power. 

pardon my dreaming here, but if I had a sponsor who would front me a LiFePO pack and a robust BMS, I think I could make the 60 amp thru the batteries idea work. But with my current pack of Deka GC8V batts, it's probably a no-go. 

As soon as I get my controller back from Logisystem, estimated at the week after Labor day, then I can do some speed/amperage measurements to get a better idea what I will need for power. I've already got a buyer for my Logisystem, and that money will go to a water cooled controller.

I started calling and emailing around for a Netgain controller. It appears they are hot items. I have not connected with one vendor who has one on the shelf available for me to buy. They all tell me they are sold out of them. I'm told I may have to wait as long as November to get one. I don't like the sound of that. I may have to revisit Zilla or Soliton.


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## Tesseract (Sep 27, 2008)

m38mike said:


> OK, so if they are wired in parrallel, as JRP3 suggests, then I'm getting my 144v at 60 amps instead of 288v at 30amps. So far that's good. But then rillip3 brings up a very good point. I'm trying to shove 60amps into batteries that boil if they get 30 or 40 amps.


The Zivan's are isolated so you could also get two rated for 72V and charge each half of the pack like that. I wouldn't place any bets on them behaving properly if you tried to connect two 144V chargers in parallel - the regulation loops may interfere with each other, especially in constant voltage mode (ie - at the end of the charge).

As for "overcharging" the battery pack, you are basically making your vehicle a series hybrid so the controller is going to be drawing, say, 100A from the pack while the chargers dump back in, say, 60A. Your battery pack will still be experiencing a net draw most of the time, though, yes, stopping for fuel, to eat, etc., will result in all of the charge current being dumped into the batteries. This argues strongly for AGM - or even better, LFP - rather than flooded.


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## JRP3 (Mar 7, 2008)

A single PFC 50 would probably be a better choice, if you have cells that can handle it. 50 amps in and up to 75 amps out depending on pack voltage. $3,300 Edit: That price is for the standard 50 amps out model. Buck enhanced gives 75 out but costs $3,850.


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## speedboats (Jan 10, 2009)

Would it not be simple enough to regulate the amps to the pack at a safe level? Because it'd be wired in parrallel, any excess'd be taken up by the drive motor, or temporarly wasted.

Gas turbine motors are quite efficent, better than a typical reciprocator. Alot of this is due to the fact that all the moving parts have a constant speed rather than the radical rates of acceleration and decceleration seen by heavy parts in the reciprocator (pistons, con-rods, valves, rockers, springs, push-rods, injectors etc. This has been done before in modular form in series hybrid busses built in NC.


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## speedboats (Jan 10, 2009)

Although I haven't made contact with these people, you could try here
http://www.bladonjets.com/

News clip about the series hybrid bus... http://www.greencarcongress.com/2007/10/microturbine-se.html


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## Duncan (Dec 8, 2008)

Hi Speedboats

_*Gas turbine motors are quite efficent, better than a typical reciprocator.*_

Where did you find this??
A small gas turbine has a terrible efficiency - the reciprocating motion is unaesthetic but not inefficient

You can use massive re-generators to increase the efficiency of your small gas turbine - but don't expect it to be nearly as efficient as a small diesel


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## Jimdear2 (Oct 12, 2008)

Mike,

Multiple chargers work fine as long as the chargers are sized to work with the portion of the pack you are charging.

Example: a 144 volt pack would require two chargers at 72 volts each charger wired to half of the batteries. Or 4 chargers at 36 volts, each charger wired to 1/4 of the pack.

Do me and yourself a big favor and contact the electrical engeineering department at the State university nearest to you. Most of those departments are starved for real world challenges.

Range extender generator trailers are not a new thing. I think that you could get a setup using mostly off the shelf stuff that would allow the complete output of the gen set to be rectified and applied to the batteries/motor with appropriate voltage/charge control. It should be possible to size the setup to not only run the motor but keep your pack fully charged.

I believe there are home use, propane fueled, emergency power units that have built in load control through voltage regulation and or throttle control. I may be wrong but I think these units come in all sizes. You should have no problem mounting one of these onto a trailer. Once you know how many watt hours you are using on an average trip you will be a lot nearer to knowing watt (pun intended) you need in a gen set.

Good luck,
Jim


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## m38mike (Dec 27, 2008)

Jimdear, I think you're spot-on. My first challenge is correctly getting the W/mph for the jeep with a trailer. Can't wait to get my controller back. 

In the mean time, I'll talk with someone in the school of engineering at Colorado State to see if they are interested in taking this on. I think I'd like to explore the idea of building a rectifier to take the generator output and feed the controller. And if the Gen is big enough, maybe when I'm running on gen power, I can also tap it to feed my onboard charger to keep the pack topped off. That way it's ready when I need it.


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## JRP3 (Mar 7, 2008)

How about this idea, a receiver hitch on the Jeep and a receiver platform that the generator sits on. Since you won't need a trailer you add minimal weight, rolling resistance, and aero drag. The Jeep should easily handle 250-300lbs back there. 5-6kw genset should be less than 250lbs, and the more weight and drag you add to the system the more power you'll need.


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## m38mike (Dec 27, 2008)

JRP3, I thought about that idea, hanging a gen on the back of the jeep. unfortunately, with over half of my pack located back there, the rear springs are already at thier limit. Take a look at the photo below.










So I think my best option is to use a trailer. That'll give me more flexibility in the size of the generator I can haul, plus it give me extra room to haul fuel, tools, parts, etc that I might need. I've been checking out 5 and 10 kW generators on ebay, and most weigh in around 4-700 lbs for a 5kW and about a hundred more for 10kW. That's more than I want to carry on the jeep, even without my batteries. 

I saw a really nice Mitsubishi diesel gen, 20kW, that's the size of a typical 10kW, that I know would get me down the road with power to spare. All for only a few thousand $$$ more than I have to spare. And it would fit nicely on my trailer too!


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## JRP3 (Mar 7, 2008)

Considering the weights you mention I guess you're only looking at diesel generators? I know you want reliability but it sounds a bit like overkill, and you'll be using more energy pulling that extra weight. Of course if you have the extra generating capacity I guess it doesn't matter as much.


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## samborambo (Aug 27, 2008)

There's quite a few posts here about adding a battery charger from the genset AC output to charge the batteries. I think this is complicated, inefficient and expensive. A wound rotor alternator (not permanent magnet) is common on most gensets and serves as a good method of regulating the output. It works similarly to a sepex motor although the field is controlled on the rotor, not the stator. Varying the DC field (usually <12V) on the rotor controls the AC BEMF of the stator windings to stabilise the AC voltage. This is usually done by an electronic governor.

For your requirements, the 3 phase AC output from the stator can be directly rectified to the DC bus via a 6 way diode bridge. A current sensor should be placed inline on the DC side of the bridge. The electronic governor needs to be modified for constant DC current governing. I suggest that the DC current reference should be tied to the vehicle speed. the DC current vs speed won't be linear but a small microcontroller with a look up table could handle that.

Sam.


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## Jimdear2 (Oct 12, 2008)

samborambo said:


> There's quite a few posts here about adding a battery charger from the genset AC output to charge the batteries. I think this is complicated, inefficient and expensive. A wound rotor alternator (not permanent magnet) is common on most gensets and serves as a good method of regulating the output. It works similarly to a sepex motor although the field is controlled on the rotor, not the stator. Varying the DC field (usually <12V) on the rotor controls the AC BEMF of the stator windings to stabilise the AC voltage. This is usually done by an electronic governor.
> 
> For your requirements, the 3 phase AC output from the stator can be directly rectified to the DC bus via a 6 way diode bridge. A current sensor should be placed inline on the DC side of the bridge. The electronic governor needs to be modified for constant DC current governing. I suggest that the DC current reference should be tied to the vehicle speed. the DC current vs speed won't be linear but a small microcontroller with a look up table could handle that.
> 
> Sam.


Sam,

What you are suggsting is exactly why I recommended that Mike contact a State Univrsity (more likely to help a State resident/taxpayer). I know in general that what you describe is possible, I just don't have the specific knowledge on how to do it or describe it. 

I agree that adding expensive chargers to the mixture is just adding extra expense and failure points.

Properly set up and sized Mike could use the trailer to go any distance on the highway and arrive in town with a fully charged pack for quiet running. Even park the trailer in secure parking. Then on the trip home run the genset again to get home.

As long as he had access to the trailer he would never run out of power.

When parked at home the generator would be a nice emergency back up. And think about renting it out for private parties and fairs in wilderness areas. Makeing money is alwys nice.

Fun brainstorming and thinking,
Jim


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## m38mike (Dec 27, 2008)

Hi Sam,
Talk about complicated. your idea of the 6 way diode bridge sounds complicated to me, but I don't know much about building electrical systems. But what I do understand - generally - is that you have proposed an idea for a device that will take the 3-phase power from the generator and turn it into DC power that the controller and motor can use. YES!! That's been what I wanted to learn about from the very beginning. 

I have no idea what a "6 way diode bridge" is, or how complicated/easy it is to build. Or is it something I could buy off the shelf? Do you have a more complete description for me? Or a diagram of how it's built? How big is it? I'm guessing that it would be a purpose-built device that would be designed to match the generator capability. Did I get that right??

JRP3, Yeah, I guess I am leaning hard on a diesel generator vs propane or gasoline. One issue is fuel availability. I'm assuming I'll need to refuel every day. I'm not sure what the propane availability is along the Alaska Highway. Years ago propane was available in the towns, but the towns were 2 days apart. Most of the stops along the highway are simply gas stations with big parking lots, and they are as much as 80 miles apart. But because of the heavy truck traffic along that highway, there is always lots of diesel available. Most of the gas stations are so far off the grid, they have to run their own diesel generators to keep the power on. It's primitive country, and it hasn't changed much over the last 60 years. Too cold and too sparse to draw very many newcomers to the area. That's part of the draw for me. I like rough country.


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## samborambo (Aug 27, 2008)

m38mike said:


> Hi Sam,
> Talk about complicated. your idea of the 6 way diode bridge sounds complicated to me, but I don't know much about building electrical systems. But what I do understand - generally - is that you have proposed an idea for a device that will take the 3-phase power from the generator and turn it into DC power that the controller and motor can use. YES!! That's been what I wanted to learn about from the very beginning.
> 
> I have no idea what a "6 way diode bridge" is, or how complicated/easy it is to build. Or is it something I could buy off the shelf? Do you have a more complete description for me? Or a diagram of how it's built? How big is it? I'm guessing that it would be a purpose-built device that would be designed to match the generator capability. Did I get that right??


Did you check Wikipedia? 

http://en.wikipedia.org/wiki/Diode_bridge#Polyphase_diode_bridges

Sam.


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## samborambo (Aug 27, 2008)

Jimdear2 said:


> Sam,
> 
> What you are suggsting is exactly why I recommended that Mike contact a State Univrsity (more likely to help a State resident/taxpayer). I know in general that what you describe is possible, I just don't have the specific knowledge on how to do it or describe it.
> 
> ...


Sorry Jim, I only skimmed through the thread before posting 

You're right, if Mike isn't particularly electronically minded, an engineering student looking for a project for university would probably be quite interested. The scope of the electronics would fit quite nicely in a semester paper (1/4 full time study).

Sam.


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## Tesseract (Sep 27, 2008)

samborambo said:


> There's quite a few posts here about adding a battery charger from the genset AC output to charge the batteries. I think this is complicated, inefficient and expensive.
> ...
> For your requirements, the 3 phase AC output from the stator can be directly rectified to the DC bus via a 6 way diode bridge.


I agree... and I suggested the same thing in post 16 of this thread...

"thump-thump-thump... is this thing on?"


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## JRP3 (Mar 7, 2008)

Tesseract said:


> I agree... and I suggested the same thing in post 16 of this thread...
> 
> "thump-thump-thump... is this thing on?"


Yeah but Sam said "6 way diode bridge".


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## m38mike (Dec 27, 2008)

Thank you Sam. For a non-EE like me, that explaination hit home. Now I get it, and I'm on board with the idea of a 6-bridge rectifier. 

Tesseract, you did bring it up earlier, but I was so focused on the concept of building my own generator that you had suggested, that I completely missed the full wave rectifier comment. 

JRP3, I still plan to contact CSU - engineering to see if there is any interest in helping me out with this, but I've got to tell you, I'm getting a very good education just in the discussions in this thread. 

So now this raises some questions for me. I see now how a 6-bridge or full wave rectifier can take the 3 phase AC current and turn it into a fairly smooth DC current. My first question is how do you regulate the voltage and the current downstream from the rectifier? 

Tesseract, you indicated that the rectified DC would be about 165vdc. Would that be true using the 208vac 3ph? Would the same be true using the 240vac 1ph? Which would be better to convert?

Keeping in mind that my current pack is composed of 18 8v deep cycle lead-acid batts. 165vdc would put 9v in each battery. That seems like a marginal charge for each battery. Is there a way to increase that to about 180vdc, or 10v per battery?


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## samborambo (Aug 27, 2008)

m38mike said:


> So now this raises some questions for me. I see now how a 6-bridge or full wave rectifier can take the 3 phase AC current and turn it into a fairly smooth DC current. My first question is how do you regulate the voltage and the current downstream from the rectifier?
> 
> Tesseract, you indicated that the rectified DC would be about 165vdc. Would that be true using the 208vac 3ph? Would the same be true using the 240vac 1ph? Which would be better to convert?
> 
> Keeping in mind that my current pack is composed of 18 8v deep cycle lead-acid batts. 165vdc would put 9v in each battery. That seems like a marginal charge for each battery. Is there a way to increase that to about 180vdc, or 10v per battery?


Read the rest of my post #39 about modifying / rebuilding the governor. That will regulate the current on to the DC bus.

Sam.


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## Tesseract (Sep 27, 2008)

m38mike said:


> Tesseract, you indicated that the rectified DC would be about 165vdc. Would that be true using the 208vac 3ph? Would the same be true using the 240vac 1ph? Which would be better to convert?


Nope, nope, depends, in that order.

208 Wye is 208V from phase to phase, but 120V from phase to neutral (common). If you let the neutral float when you full-wave rectify and capacitor filter the 3 phase output you will get a DC voltage of 208 x 1.414 = 294VDC. If you half-wave rectify the 3 phases referenced to the neutral you get 120 x (1.414*0.841) = ~143VDC.

From a 240VAC 1ph. output you will get ~340VDC.

Half-wave rectifiers are not recommended because they cause a DC current to circulate in the transformers, generators, etc., feeding them so scratch that circuit off the list.



m38mike said:


> Keeping in mind that my current pack is composed of 18 8v deep cycle lead-acid batts. 165vdc would put 9v in each battery. That seems like a marginal charge for each battery. Is there a way to increase that to about 180vdc, or 10v per battery?


Yes, and like I said that is almost a perfect float voltage for any lead-acid battery type - AGM, flooded or gel. 10V per 8V battery is closer to equalization voltage for flooded and is higher than the maximum recommended charging voltage for both AGM and gel (2.4V/cell max).

Best thing to do is either stick with 144V, or adjust the voltage regulator circuit on the generator to accommodate something different, or double the pack to 288V and use the 240VAC output, or go up to 252V nominal and use the 3ph. 208Y output.

This is probably getting confusing... if so, then there is no shame in simply going with regular old chargers. Maybe consider a couple of Elcon 3kW models. Still budget friendly and Rebirth Auto seems to like them well enough.


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## samborambo (Aug 27, 2008)

Cost of an Elcon 3kW charger = US$1100
Cost of having a 15kW generator's alternator rewound to a suitable voltage = ~US$700

Sam.


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## m38mike (Dec 27, 2008)

So if I bridge rectify 120vac I should have ~165vdc. And from a 5kW gen I should have ~40amps, or ~80amps from a 10kW gen. Or do I drop to 30a and 60a respectively downstream of the rectifier? Maybe thats a dumb question, or maybe I'm just thinking slowly here. 

I think I'd like to stick with a 144v system. I may change batteries between now and then, but for the moment I need to plan on using what I have. In reviewing all the comments on this thread, what I'm seeing is that I need to get my controller back in and test my current use at different speeds, with a trailer attached, to determine my true power requirement. 

Once I establish that requirement, then I need a generator with large enough capacity to match that requirement. To determine if the gen capacity is large enough I need to consider the output if I were to rectify the 120vac into ~165vdc. I also need to be sure that the requirement is compared to 70-80% of the gen capacity so I can have some confidence that the gen can operate at that capacity for day after day for weeks.

I think I like the idea of using a rectifier and feeding power into the pack vs. using a charger to feed power into the pack. But because this is new ground for me, I don't know what the problems might be that I might face. Any advice on that topic???

I'll google to see what I can find for rectifiers, but can you point me toward a source that might have what I need? While I'm still in learn mode, what should I look for when looking at rectifiers?

Thanks guys for all your thoughts and ideas.


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## samborambo (Aug 27, 2008)

m38mike said:


> So if I bridge rectify 120vac I should have ~165vdc. And from a 5kW gen I should have ~40amps, or ~80amps from a 10kW gen. Or do I drop to 30a and 60a respectively downstream of the rectifier? Maybe thats a dumb question, or maybe I'm just thinking slowly here.
> 
> I think I'd like to stick with a 144v system. I may change batteries between now and then, but for the moment I need to plan on using what I have. In reviewing all the comments on this thread, what I'm seeing is that I need to get my controller back in and test my current use at different speeds, with a trailer attached, to determine my true power requirement.
> 
> ...


Since the generator is running virtually constantly (to maintain efficiency), you'd only want to put a float voltage on your 144VDC cells - around 160VDC. The ideal 3P phase to phase voltage from the alternator would be 160 / sqrt(2) = 113VAC. The governor will control that voltage and current so anything +/- 10% of that AC voltage would be fine.

EDIT: Your current should be determined by measuring the voltage and current to find the DC power required. THEN divide by the float voltage (160VDC). This is because your batteries will sag in voltage in a normal BEV but with the batteries being floated the voltage is higher and therefore the current is lower. That said, you may want to add about 20% to the power required for charging the batteries for acceleration. 

Now to determine the line current. Let's base it on 150A DC for highway usage. You can scale these figures once you know your requirements. The basic theory in determining the current through a rectifier is to work on power in vs power out minus the (usually negligible) diode volt drop. The power out is 150 * 160 = 24000W. Power in assuming the diode drop of 1V is 24000 + (3 * Vdiode * 150) = 24450W. 

Remember that the 450W power lost in the rectifier needs to be dissipated properly. When sourcing diodes or rectifier modules, carefully consider these parameters:



Forward voltage drop vs current. The lower the better to maintain efficiency and lower cooling requirement.
Continuous current rating. This should be at least your DC current required for this application. Add a safety margin of 30%.
Reverse blocking voltage. This should be 3 times the 120VAC since the alternator may produce some voltage surges.
Rth(j-c) or thermal resistance (junction to case). Consider this along with the max operating temperature and the expected power dissipation. The Rth(j-c) determines how much power you can dissipate to keep under the max operating temperature (with some safety factor, of course). For your application dissipating hundreds of watts per phase leg, you're only looking at larger modules that can be bolted to a heatsink with some forced cooling.

OK, so that's a 3p 120VAC 25kW generator. That's not the end of the story though. As you can see from that Wikipedia page on rectifiers, full wave rectification of 3 phase power results in low DC ripple voltage / current. It also means that the current is only being drawn from the AC source 1/3 of the time on each phase, resulting in an increase in AC harmonic distortion. The end result is that the power factor of the AC system drops considerably. The actual size of your alternator will not be determined by the real power of the electrical system (25kW) but rather the apparent power required due to the harmonic distortion.

Off the top of my head I can't remember the formula for working out the power factor of a 3 phase rectifier. I would assume around 0.7 resulting in 25kW / 0.7 = 35kVA. Of course the 35kVA is just the apparent power and really describes the current rating of the AC system, not the real power. The sizing of the prime mover will still be based on the real 25kW.

Sam.


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## DIYguy (Sep 18, 2008)

Bowser330 said:


> http://www.evconsultinginc.com/articles/hybridizing_dc_system.html
> 
> quote]
> 
> ...


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## m38mike (Dec 27, 2008)

Thanks DIYguy, I'm glad to hear from someone who's been down this road before me. Your link to the EV consulting site is interesting. I see you took the method 1 approach. I see that way as being fairly straight forward, but a bit spendy to get a charger that'll push the current needed. But I also see it as being safer for the batteries, because the charger will monitor the batteries as it pushes current into them. 

But as I read the EV Consulting site on using the bridge rectifier, I found some info that is in conflict with what I'm hearing from Tesseract and Sam. Let me post it to see if I understand it correctly.


A battery pack must be employed which is no less than 96 volts, nor more than 108 volts. This requirement must be strictly adhered to for good compatibility and power balance. If a pack is less than 96 volts, the drive system will draw too much power from the generator, but not enough from the batteries. If the pack is more than 108 volts, the drive system will draw too much power from the batteries, but not enough from the gen-set. If no batteries are used, the voltage ripple of the power bridge rectifier output may be excessive and damage the motor controller.
The battery voltage must be monitored, and the gen-set power must be cut back if the battery voltage is more than 2.35 volts/cell. For a 96-volt pack, this voltage is 113 volts; for a 108-volt pack, this voltage is 127 volts. Exceeding this voltage while driving high current into the battery pack will cause excessive battery heat and excessive battery gassing.
According to this, I should not use a bridge rectifier to charge a 144v pack. Because the site does not develop the idea more, It's hard for me to understand why they impose such a narrow limit to the pack voltage. If I recall what Tesseract said correctly, if I use a bridge rectifier to convert 120vac 1ph to DC then I should get ~165vdc, which is a good float voltage value for a 144vdc pack. So I wonder what assumptions EV Consulting based these instruction on?? I may have to call to find out. 
*Sam*, thanks for talking me through your thoughts on calculating the current requirements. And also for the heads up on what to watch for when looking for bridge rectifiers. I did some looking on the digi-key web site. WOW! What a lot of choices! After an hour or so of wandering around there, I came away with the idea that I need to establish my base power requirement, then size the gen set to provide it, then size the rectifier to match the gen to the pack. I was surprised at how inexpensive a 35amp 800v bridge rectifier is. I expected it to be more. 

*Jimdear*, I've been doing more thinking about your comments on weight, and propane generators. I'm looking at the p.g.'s a bit closer based on your encouragement. I've been surprised by how lite some of them are. I still have the fuel availability concern along the Al-Can Highway. I may have to order a copy of Milepost to see who carries what kind of fuel along that route. If you've never driven to Alaska, then you might not know about Milepost. It's a catalog/magazine that lists every store, gas station, town, and tourist trap from Dawson BC to Anchorage AK, mile by mile. That source would tell me how available propane is along the route. It would also tell me how much of the route is asphalt and how much is gravel. But a check of the photos from our trip in 1979 reminded me of the mountains we went over. So having a powerplant that's light could be a real bonus. That would allow me to carry more fuel tanks, or a couple larger ones. And it should run quieter too. That'd be a big plus!


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## m38mike (Dec 27, 2008)

I called Ken at EV Consulting about his article. He talked with me for about 20 minutes as we discussed different possible combinations of parts and power outputs. The bottom line on why he did not recommend using 120vac thru a bridge for any voltage above about 108vdc is because as the Generator load increases he said the voltage would decrease, similar to what a pack of batteries would do. He said that even though 120vac would peak at ~163vdc going through a bridge, under load it would be closer to 108+vdc. 

He said it would be better to use the 240vac and run that thru a transformer so the voltage would be about 170vac, then thru a bridge, then connected to a 144vdc pack. He said that would give the best voltage design under load from the gen to the pack. 

Thoughts????


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## samborambo (Aug 27, 2008)

Mike, there's no conflict. What you're describing is matching the battery pack voltage to a constant AC voltage source - ie: a generator with a standard voltage governor. There's no disputing that this method may work - just that you may be constrained in the range of current you can draw from the generator. You may go through significant trial and error in trying to match the battery voltage to the generator and still be limited as to when the generator can run.

My recommendation of modifying the governor will give you full dynamic control over voltage and current - letting choose the battery voltage most appropriate for the rest of the system.

Sam.


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## sailfish11 (Sep 15, 2007)

Doesn't anyone already sell something like this? I Googled 'generator trailer' and found references to the old "Long Ranger" by AC Propulsion, but I couldn't find that for sale anywhere.... Surely someone makes an EV range-extending trailer.


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## major (Apr 4, 2008)

sailfish11 said:


> Doesn't anyone already sell something like this? I Googled 'generator trailer' and found references to the old "Long Ranger" by AC Propulsion, but I couldn't find that for sale anywhere.... Surely someone makes an EV range-extending trailer.


Hey sail,

Why in the world would you think "Surely someone makes an EV range-extending trailer"? There must be a couple thousand of EVs on the road today of various voltage systems. That is a heck of a market for "someone" to develop a product which might sell one or two a year 

Other than that, good idea 

major


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## sailfish11 (Sep 15, 2007)

You might be right, but I'd think you'd sell more than one or two a year. If someone designed and built a turn-key small trailer-mounted generator (similar to the Long Ranger) that put out 110V or 240V, I'd think there'd be a market for it. The Long Ranger put out 25Kw and had a complicated back up assist -- you wouldn't need anything that elaborate or powerful.

I'm sure it's not the easiest thing in the world (or "surely someone" would have done it by now) 

Heck, a decent trailer to tow your EV will cost $1500. If you could build a genset trailer for less than $2000 I think people would buy it. It would double as a back up generator for your house. In fact, if you were real enterprising (and lived in an area with many EV'ers) you could build a couple of them and rent them out!

Sure, there may only be a few thousand EVs on the road now, but that number is growing -- and will continue to grow.


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## DawidvC (Feb 14, 2010)

Major, if we can get a reasonable design going in this thread, I for one would be grateful. My plans at this moment requires some kind of part-time serial hybrid system or range extender/emergency generator. I have some ideas that I will post later (I am posting from my phone - very akward)


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## ken1939 (Sep 4, 2010)

I'm sure it's not the easiest thing in the world (or "surely someone" would have done it by now) 


Its not so much that, to me there are three reasons. 

One, not many people are thinking of a "Demand" for such a device. I have had this idea in my head for a long time, feeling its the only way to build a reliable, non stopable, go anywhere, EV/Hybrid. And your choices can be propane, gas or diesel. Oh look, its the Volt...

For some, this is engineering that is far out of the box for most homebuilders. Its kind of like the EAA, you can build your own airplane, which is cool. However, most folks arent building a home aircraft with a jet engine. Yet....(oh its on its way)

The third reason I have run into, and is one of the reasons I have not really gotten involved in many of the EV groups is the bias toward ANY mention or use of a alternate source of power other than batteries.

Purists if you will? I appreciate the work some of these folks have done. Some good engineering and fabrication. 

As I mentioned in my intro, I am on this forum because I see people with real discussions and wanting to really push this from a 20 mile golf cart project to something that performs and is useful. This thread is one of the examples.


BRAVO


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## JRP3 (Mar 7, 2008)

Another reason you don't see them is because most of us have a second vehicle with an ICE. So for the few times I need to go farther I could build a genset trailer, or just hop in my ICE.


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## Woodsmith (Jun 5, 2008)

I think, in the UK (and I will have to look into this), it isn't legal to leave your vehicle engine running when you are not with the vehicle. I am not sure how this would apply, or how the wardens would know, that the running engine is only charging batteries and not liable to drive the vehicle away. It may be more obvious if it were mounted on a trialer but I can also, cynic that I am, imagine that it wouldn't still be there when you return to your vehicle in the parking lot.

I may have to consider all this for my commuter and balance the extra weight against the range reduction for carrying/towing the generator.


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## samborambo (Aug 27, 2008)

Woodsmith said:


> I think, in the UK (and I will have to look into this), it isn't legal to leave your vehicle engine running when you are not with the vehicle. I am not sure how this would apply, or how the wardens would know, that the running engine is only charging batteries and not liable to drive the vehicle away. It may be more obvious if it were mounted on a trialer but I can also, cynic that I am, imagine that it wouldn't still be there when you return to your vehicle in the parking lot.
> 
> I may have to consider all this for my commuter and balance the extra weight against the range reduction for carrying/towing the generator.


That's ridiculous. What happens if you have a turbo timer that runs for a minute or so after you stop? No one here in NZ waits for the turbo timeout before locking the car and walking away. 

Besides, it's a generator trailer, not a car engine. Surely you don't need to stand around watching back-up generators in the UK? 

Sam.


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## Woodsmith (Jun 5, 2008)

Last time I checked it was definately not legal to leave a vehicle with its engine running.
If I have just done a long fast run I will sit in my car while the turbo is cooling down before shutting off and leaving it. I generally try to include some slow urban driving at the end of the trip to give it a chance to cool before I need to stop.

Generators running in a trailer would be fine left but someone would nick it.


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## sailfish11 (Sep 15, 2007)

Ok, so a quick Google search says I can get a 10Kw generator for about $1000 and a small trailer for about $200. Other than mounting hardware and other small items, what else would you need?


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## m38mike (Dec 27, 2008)

I've been searching for a "turn-key" generator trailer, with the idea that I could duplicate it for my need, but I've come up empty so far. One person has responded with "I did it" but I don't have any testing data from him that would help me. I would like to develop my trailer in this forum so others can benefit from learning about the traps that might catch me along the way. 

The latest concept that I want to test is that a generator set does not maintain a constant voltage irregardless of the load. My understanding was that a gen set produced 120vac if I had one light bulb or a whole house plugged into it. I've been told that a gen set will drop voltage similar to a battery pack. I guess the question is how much will it drop. So I'm enlisting the help of two of my brothers-in-law, both owning generators, to see what happens when the gen set is loaded. 

That idea is important to my concept of how I'd like to build my trailer. If it is variable over a wide range, that'll make adjusting it more difficult. If it varies over a narrow range, then I can target my power needs more carefully in whatever I use (bridge rectifier, charger) to convert the AC to DC to power my EV. 

Speaking of targeting my power needs, my controller should be coming back from Logisystem this week. So by this coming weekend I hope to be doing some power tests with a loaded trailer behind the EV.


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## major (Apr 4, 2008)

m38mike said:


> I've been searching for a "turn-key" generator trailer, with the idea that I could duplicate it for my need, but I've come up empty so far.


Hey m38,

I've been staying out of this for the most part. Got my nose in too many things already. But WTH.

You need a source of regulated DC. Why not use a DC generator? All motors are generators and vice versa, if properly excited. So, get a Warp9 and have is rewound to a shunt machine. Then belt drive it from a suitable engine so you get the proper RPM. Then you simply wire the armature to the battery pack and control the field to set the proper voltage.

Yeah, the devil is in the details. But this method requires no power electronics (well maybe a diode). Just a field control, maybe a few amps. 

Just a thought.

major


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## JRP3 (Mar 7, 2008)

Why use a Warp9? Why not look for a shunt motor, like one of those 11 inchers that Todd has which no one can find a decent controller for anyway?


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## major (Apr 4, 2008)

JRP3 said:


> Why use a Warp9? Why not look for a shunt motor, like one of those 11 inchers that Todd has which no one can find a decent controller for anyway?


Seems bigger than needed. And Warp9 was just a starting suggestion. Until Mike gets some data, we don't know the power required. Maybe a 7 incher would do the trick at a little higher RPM.


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## m38mike (Dec 27, 2008)

sailfish11, "besides the trailer and a gen set what else would you need?" How about something to make the gen set power compatible with the EV? If your EV runs on 240vac, you're in luck. Mine doesn't. It's 144vdc, so I need to convert it, or destroy my EV trying to use it.

Major, the DC motor idea has been proposed, and is interesting to me, but without a very good example to follow, and a good mentor to help see me through building that, I'm hesitant to jump into that project. I don't have a strong electric engineering background. I can see using a standard AC gen set with either a bridge rectifier or a high wattage charger as probably my best course of action. The advantage of that is the generator can be used for many other applications, like powering tools on the road, keeping my home lit up in a power outage, etc. 

One thought on a parrallel path that I have had is to use a DC welder as my power source. I'd need a fairly large one, since most of the small ones tend to use 48 volts or less. Some of the bigger ones will feed out up to 180vdc.


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## DawidvC (Feb 14, 2010)

If you use a shunt wound motor, you can modulate the field to regulate the voltage or current. ( You can probably do both, but that need some serious thinking about) Most bigger AC genset use some form of voltage control, whereby they regulate their field ( that is on the rotor ) to adjust the output voltage. I have seen some nice sets in smaller capacities ( 7 - 25kw ) that also have similar systems. If you need constant current, it should again be possible to modify the regulator to compensate.

I have been thinking along the lines of a high-speed slipring ac motor, driven by a smallish bike engine (watercooled). Injecting a DC current into the sliprings so that 2 phases carry part of the current, it will make a decent generator. We have several slipring crane motors that has been replace with induction motors and drives, so there should be a ready source of these motors.

To regulate the output voltage or current, you would then need something like a small DC controller to regulate the current going into the sliprings. As the frequency of the output is irrelevant, running a small bike engine at its peak torque rpm and rewinding the motor to give me a suitable voltage to rectify should be satisfactory.

Dawid


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## major (Apr 4, 2008)

m38mike said:


> One thought on a parrallel path that I have had is to use a DC welder as my power source. I'd need a fairly large one, since most of the small ones tend to use 48 volts or less. Some of the bigger ones will feed out up to 180vdc.


Hey m38,

I've built welder powered EVs without batteries at around 40 volts. Just low speed guys, 10 mph or less, but over 1000 lbs. Works nicely. Didn't know of a welder generator going much higher in voltage.

You had contact with Warfield or Netgain back when you had the shaft problem. Maybe you could contact them and see if they would wind a 7 or 9 as a shunt generator for you. To me, it seems easy for them to do, seeing as how they have (or should have) the saturation map and winding blocks for the motors.

Control could be as easy as a couple of ammeters and voltmeter with a field adjustment pot using the driver as the feedback regulator. But I suppose one of these smart guys here could configure an automatic circuit for you. 

Regards,

major


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## m38mike (Dec 27, 2008)

Dawid and Major,

I would think that if a DC generator is regulated for voltage, then amperage could be variable with increases or decreases in generator rpm, and demand would be based on changes in speed or slope on the road. Ideally I would like to be able to feed a fixed voltage and variable current into the pack, and let the pack power the motor to make the EV go. That would allow the pack to cover the spikes in power required (like going up hills) while absorbing energy during low power times (like coasting downhill). Once I've determined my power requirement for various speeds, then I can figure out what speed I want to design my power-trailer for, and figure out just how much power I need in a generator. Then with all roads being level, if I go faster, I draw down the pack. If I go slower, I keep the pack full and essentially run off the gen set. 

That could be a good arguement for a fixed rpm, fixed voltage, fixed current generator. If I operated the pack in the 50-90% charged state, then I could always push current into the pack. I'd need a good way to shut down the gen set safely and quickly for those times when we might be not moving, and the pack is 90% plus. Perhaps cut the power feed with a contactor, and let the gen engine idle down.


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## sailfish11 (Sep 15, 2007)

Here's an example of something similar to what I was trying to describe:
http://www.evnut.com/docs/rav_docs/rav4evpfc50.pdf

My idea was to set it up as a trailer, which would increase drag but also add versatility.


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## m38mike (Dec 27, 2008)

sailfish11,
yup, that is exactly what I hope to accomplish. My only hangup on this configuration is the price of the Manzanita charger, anywhere from $3300 to $4500 depending on if I got a PFC-50 or PFC-75. The same could be said about the high end Zivan's as well. But that expense may well be worth it in the long run. Manzanita or Zivan have done all the conversion engineering for me, and created the box that will take what I have in gen set output and give me what I need for battery pack input.

Looking at bridge rectifiers on the Digi-Key site I saw that most of them are under $100 each which is very attractive and very do-able. That's why if I could simply rectify a gen set's output, that would be the cost-concious way to go.


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## m38mike (Dec 27, 2008)

I talked with Jim at Logisystems this morning. Seems they had an accident in their testing shop. The live load on their test motor went "live" and tore up the test equipment. They've been rebuilding all week and should be back up and testing this afternoon. But what that means to me is my controller will not be back until next week some time. So this weekend's plans to test are out the window.  Guess I'll have to do some other maintenance on the Electro-Willys. Maybe my LED lights will arrive and I can replace the bulbs in my lights.


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## m38mike (Dec 27, 2008)

Talked with Jim at Logisystems again today. My controller passed their tests and got shipped out this afternoon. I expect to get it about next Wednesday. But since I've got company all next week, I will get the controller plugged back in, but I may not get my testing done right away. Then again, my company are all jeep folk, so maybe they can help me with the testing. That might work..........


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## sjc (Oct 28, 2008)

So, to potentially hijack this thread, has anyone considered range extenders for LiFePO4 packs with BMS? 

I have a 144v 160Ah Thundersky pack (still sitting in the garage, as the vehicle is still in process). I'm using Dimitri's MiniBMS, and my charger is a 3Kw Elcon (my expected daily driving range is only 15 or so miles, so in regular use I should have plenty of time to recharge without concern; a fully drained pack, which I should never see, would charge in roughly 8 hours).

I have a possibly irrational fear that charging while driving might cause problems for my BMS, and that I might end up harming my nice expensive pack. Are my fears groundless?


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## JRP3 (Mar 7, 2008)

Can't imagine any problems, you could always check with Dimitri for confirmation.


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## m38mike (Dec 27, 2008)

SJC, I would think that with a 144v 160ah TS pack you should be able to do 30-40 miles with that pack. Are you not getting that far? 

I am also interested in hearing if you can charge and discharge without damage to your BMS. I am considering replacing my LA pack with a TS pack for this adventure I'm hoping to go on in 2 years. 

In the mean time, I recieved my LS controller back last wednesday, as promised. Within a half hour I had it all re-installed and started driving again. I had about 30 old-jeep owners at my home for a jeep tour in the mountains, and they all wanted to be able to drive Electro-Willys. They all got to do just that. My rebuilt controller was a 120-144v, 1000a controller. Now it's a 72-168v, 1000a controller. It's very responsive. I have not used it to the point where the new heat control circuit would start shutting down power yet. I hope I never do. I still plan to buy a water cooled controller in the near future because I expect that my planned 3500 mile trip will greatly tax all my systems, especially the controller. 

This weekend I'm going to hook up a trailer loaded with firewood to the E-W to simulate a trailer with a generator. Then I'll drive on a flat road at different speeds, in 5 mph increments, to see what my Voltage/amperage load is on the batteries. I plan to video each drive so I can pause every 5 seconds when I'm reviewing the video and record the values from the gauges. Then I'll average the values for each speed driven, and graph the averages to get a feel for my power requirements as my speed increases.

This should also give me a clue about the size of generator I'll need to maintain a certain speed. I plan to post the test videos onto u-tube. And I'll post the results on this thread. I'll also post links to the videos on this thread. My gauges are all on the battery side of the controller, because it's the batteries/power supply that I'm concerned with. I really don't need to know what the controller is doing with the power (V vs A), but I do need to know what is being drawn from the batteries. I'll also add a photo or two of Electro-Willys with the trailer so everyone can see what I'm working with.


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## major (Apr 4, 2008)

m38mike said:


> This weekend I'm going to hook up a trailer loaded with firewood to the E-W


Something like this


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## m38mike (Dec 27, 2008)

You got it Major!  Only I'll have to do a better job of stacking the wood so I don't loose it all out on the road!


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## JRP3 (Mar 7, 2008)

m38mike said:


> SJC, I would think that with a 144v 160ah TS pack you should be able to do 30-40 miles with that pack. Are you not getting that far?


I'd think he should be getting close to twice that in his vehicle. 23kwh pack at 300wh/mi average gives 76 mile range.


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## glaurung (Nov 11, 2009)

One more option for on-board generator,
http://www.precer.com/Technology.html
click "autotech autoteck prototype"
Must be pricey but very interesting consept.Stirling generator could as well use anything that burns as fuel.
Anybody from Sweden know if they are making progress?
Harri


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## zeroemission (Sep 14, 2010)

i don't want to poopoo on this thread, but as someone who came here with the idea of building as light a vehicle as possible and powering it with an even lighter than batteries generator for a *SERIAL HYBRID*, it looks like generators driving electric are marginally better than just driving directly off an ICE motor. by the time you get a generator like an efficient honda in the 5kw or higher range, you start chugging a gallon an hour or more making the claims of the 5hp 75mpg opel GT sound like flat out lies.

i'd like to hope i'm wrong about this as slapping an efficient 50lb generator on a trailer seems like a good idea in theory if only you can generate enough watts to maintain a respectable speed. i've had little success in trying to both find & nail a complete watts per mass & MPH formula and would love to see someone break down a 100mpg+ formula for a serial hybrid that works. i like this idea for giving EVs range for long treks, but so far have given up on the idea as simply another way to get 50mpg realistically.

getting standard, even prius level, MPG isn't good enough for me. please do share any info that illuminates the magical 100mpg+ range claimed by A HUMMER for lighter vehicles like jeeps etc. i'd like to think that my idea for a 400lb battery free (in long distance mode) vehicle with a small generator & trailer system isn't the bad idea everyone has made it sound here.

it's the only way i can think to make vehicles that are efficient & capable of more than 100 miles between charges and if the 75mpg @ 5hp opel isn't really a myth, it should be possible to do much better than that with an even lighter aerodynamic minimalist 1 seater.

i really want to be WRONG here! (about the pessimism that is)


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## JRP3 (Mar 7, 2008)

This really isn't about efficiency it's about range extension. The nice thing about the trailer is you can leave it at home most of the time since you don't need it.


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## zeroemission (Sep 14, 2010)

if all you want to do is move your vehicle, then yes, it's doable.


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## Duncan (Dec 8, 2008)

Hi Glaurung,

Stirling engine technology has been used to make vehicle power units for over 100 years
- with little success!

It was originally invented to eliminate steam boiler explosions and while theoretically as efficient as the Carnot cycle it suffers from a poor work cycle ratio (which is the same reason that the Carnot cycle is not used)

It works very well as a combined heat and power unit - not so good as a prime mover

As soon as you need to get sensible power to weight ratios you need to operate above atmospheric pressure (well above, a 12Kw 50Kg unit would have to operate at over 50Bar) - effectively you have a pressure vessel with a fire burning against one side


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## m38mike (Dec 27, 2008)

Guys,
remember my objective here, design and build a gnerator trailer that will move the jeep at convoy speed for 5+ hours every day for a month. I really don't care if it get 50 mpg or 15 mpg. What is important to me is building a generator trailer that works reliably, and allows me infinite operation time in electric mode, as long as the generator has fuel. I've seen very few examples of this in practice, although several folks have expressed a strong interest, and a few have claimed past success. 

My intent is to design and build this trailer transparently, so everyone who is interested can see what I calculated, how I built it, and can adapt and copy the process or the equipment for their own trailer. I don't think that has been done yet. I enjoy the ideas that have been presented here. Some of them are causing me to do more research into what I might be able to do. But ultimately I should have a basic design that anyone can copy, without breaking the bank account, and have some reliability that it will perform as intended.


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## DIYguy (Sep 18, 2008)

hey Mike,

Just wanted to point you to another source of info... this chap from Quebec did what Sam is talking about... bit smaller scale than you want... but interesting non-the-less. http://www.evalbum.com/122.html

I've spoken to him a few times last year when I was kicking around ideas. He has (had?) a website called Vehicle Verte.... or something like that (means green car) but last time I looked it was only there in french...when previously I recall bi-lingual version. Either way, should be contact info on the link above.

I'm not this smart...  so, I chose the gen-set/charger method. I justified it a few ways... since I wanted a large onboard charger (6kw Elcon) anyways as well as a gen-set for back up power. I could post some pics of how I'm modifying the gen-set pkg if ur interested...

edit...another thought (realization).. if you are planning very low speeds as indicated....your testing may reveal the need for a relatively small gen set only....
Cheers.
Gary


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## m38mike (Dec 27, 2008)

Gary,
I'd love to see pix of your gen/charger set up! That may be the best way for me to go, since the charger can monitor the pack condition and prevent itself from overcharging. If I used a simple bridge rectifier, I'd have to monitor the gauges constantly to manually prevent overcharging. 

But I'm not sure my battery pack is going to make this trip. I took the E-W out yesterday to get it warmed up for my test, and 2 miles out from the house, the pack was about to die. I limped home at about 3 mph, and had to stop 2-3 times to let the pack self-recharge. So I put the charger on it and left it on overnight to see if I had inadvertently drawn it down. I plan to check each battery this morning to see if I have a dead one in the pack. I did check the fluid level in all the batteries before charging. They were a little low, maybe 1/4 to 1/2 inch, but none of them had plates exposed. 

I looked at Alain St-Yves web page that you linked to. Very nice what he's done with his pickup. But I noticed that with his 5kW he only extends his range by 40 miles. That indicates to me that 5kW is not enough power to keep his pickup running at his preferred speed. It's just enough to slow the battery drain. Perhaps if he had a 10kW he could go indefinitely at his preferred speed. That's what I want to be able to do. I just need to be able to get past my hurdles so I can figure out what my power need is for my convoy speed.


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## DIYguy (Sep 18, 2008)

Hi Mike,

I'll post some pics later today. Yes, 5 kw will not power continuously for sure. My set up uses a larger gen-set with 6kw charger. This is the best way to ensure you are protecting your batteries I think.... It was described as complicated..but I think that was a reference to the amount of electronics required. For people who are not EE's, it's much simpler. I need a charger anyways.... so, I plug in a gen-set, 30 amps at 240 volts. Pretty simple.

I thought your speeds were going to be quite low on this trip... no?


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## DIYguy (Sep 18, 2008)

m38mike said:


> Gary,
> But I'm not sure my battery pack is going to make this trip. I took the E-W out yesterday to get it warmed up for my test, and 2 miles out from the house, the pack was about to die. I limped home at about 3 mph, and had to stop 2-3 times to let the pack self-recharge. So I put the charger on it and left it on overnight to see if I had inadvertently drawn it down. I plan to check each battery this morning to see if I have a dead one in the pack. I did check the fluid level in all the batteries before charging. They were a little low, maybe 1/4 to 1/2 inch, but none of them had plates exposed.


How old are your batteries? cycles? How cold was it when u went? (where do u live?) Make sure you check connections as well as measure voltage on each one.


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## m38mike (Dec 27, 2008)

Well I just came back in from metering each battery. (needed more hot coffee) All of them measured from 7.8 to 8.1v. Way too low. But because they are all still connected together I think the pack is carrying the dead cell. So I'm going to pull all the cables and let the pack sit for a while. Then remeasure. Hopefully that will tell me what battery is sucking the pack down. I also noticed that my charger was displaying a code that I have not seen before. I have a Zivan 1500, and it was flashing a green, then red light, then 2 seconds of blank, then green/red and blank again. Normally it'll flash yellow about every 2 seconds when it's charging, then green when it gets to float. So it's time to go find the manual and see what green/red means. I think i'll do that before I pull all the cables. Just in case it's my charger that's going bad. 

The batteries are 2 years old, been cycled dozens of times, and it was in the 20's in the garage this morning. And I topped them up with distilled water yesterday when I was checking them.

My target speed for generator maintained power is 40 mph. The convoy speed will probably be about 30-35 mph, and I'd like a little extra to be able to catch up if I lagged behind, or was behind someone else who was slow. Imagine that - seeing northwest Canada and Alaska at 30 mph for 5 hours a day for 30 days! 

Someone recommended getting a big ipod and loading it up with tunes. I just figured I'd bring my laptop and load it up with tunes. That way if the fuel stations along the way have wifi, then I could post pix and messages while we're stopped for refueling. And if I can get my controller to talk with my PC, then I could also post my tech data in almost real time.


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## JRP3 (Mar 7, 2008)

Batteries wired in series will show individual voltages, a low one would show up.


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## m38mike (Dec 27, 2008)

JRP3 said:


> Batteries wired in series will show individual voltages, a low one would show up.


Then that tells me that I really need to examine my charger and charging wires/connections. DANG!! I hate when that happens!


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## m38mike (Dec 27, 2008)

OK, so the green/red flash indicates that the charger is overheating. Hhmmm, it's got good ventilation around it. Maybe I need to add a small 110v fan to move more air. Time to go look it over, and look for the reset button.


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## m38mike (Dec 27, 2008)

[email protected]#N!! No reset button. Charger is 35 degrees F. Giving me a "charger overheated" code. It's not putting out anything. Now I have no way to charge my pack. I guess tomorrow's task it to find out where I need to send this charger to get it repaired. 

And since I'm selling my LS controller next week to a local guy, I'm out of the testing business until I get BOTH a new controller and a repaired/new charger.  [email protected]%N the bad luck!


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## DawidvC (Feb 14, 2010)

I am sorry to hear about your charger, mike. Looking at your project you will have to look at something of at least 15kw, maybe bigger since you will be towing a trailer. If you can get hold of a nice BLDC motor of around 20kw nominal, and run it with a small bike engine, say at least 50kw, with a controller capable of regen, you will have something nice going.

BTW what I remember of military gensets (even if it is not made in USA) a 15kw genset will probably weigh around 2 tons. You do not want to tow that

Dawid


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## Jimdear2 (Oct 12, 2008)

Mike,

I was poking around on you tube when I came across this Chengfu 20kw diesel genset. A 1.6l single cylinder diesel . Can you say vibration ! ! !

http://www.youtube.com/watch?v=Ad_tMUq2u7w&feature=related

From what I could see in the video it appears to be small/light enough to mount on a trailer. They claim that they have over 9000 hours of runtime. 

This is supposed to be a copy of a German design and is supposed to be very robust.

I did a quick google on Chengfu diesel generators and came up with quite a few hits. There are some mentions of twin cylinder versions also.

20kw (26hp) should be more then enough to do the 30 - 40 mph continious you want, even with a trailer, or at least keep your batteries up near full charge for climbing those hills.

I will say, you seem to be haveing more then your share of bad luck. I hope you are over that before you go on your trip. Maybe you can work out a deal for a Soliton jr. and a good set of LiFePo or at least a set of quality AGMs. 

From all I've read about the controller you are passing on, you might be making a good choice to get rid of it. I hope you arn't turning a freind into a new enemy.

Seems like you have or will replace everything that those "conversion experts" sold/did for you. If there is anything else left, you should maybe bring spares or swap it out now.


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## m38mike (Dec 27, 2008)

Dawid, 
Not a bad idea. I'd have more interest if I thought I could really get it to work for me. That and make it look military. I've looked at some 15kW gen sets and they run about 1200-1300 lbs. Add another 500 lbs for the trailer, and a hundred lbs of spare parts and I'm up to a ton behind the jeep.

JimDear,
"This is supposed to be a copy of a German design and is supposed to be very robust." 
Yeah, like a Kelly controller is a copy of a Soliton! I'll beleive that when someone else buys one and is successful with it. 

"From all I've read about the controller you are passing on, you might be making a good choice to get rid of it. I hope you arn't turning a freind into a new enemy."
Read, the buyer, is looking forward to getting rid of his Kelly and installing my Logisystem. His system is almost a duplicate of mine, except it's in an S10. He uses his vehicle around town, not for long commutes. So I think he'll do well with it. I know intuitively that I will really work my controller, and that if I have one that isn't liquid-cooled, I'll be in trouble very quickly. So I'm looking to get a Soliton1. They seem to have a good reputation. Besides, if I can get the Soliton to talk with my laptop while on the road, I'll be able to post daily data about vehicle performance every time I can get to a wifi site at the end of each day. 

"Seems like you have or will replace everything that those "conversion experts" sold/did for you. If there is anything else left, you should maybe bring spares or swap it out now." 
Jim, you are very perceptive! That sure seems to be what's happening. I wonder why??!  My pocketbook says "I hope the 1500 charger is repairable". My head says,"This may be the time to get a Manzanita 75W charger!" 

y'know, this business of saving money with an EV is going to send me to the poor house! Maybe I should just buy a bicycle.  Some days I just need to take several deep breaths, and remember that this is a Long-Term project, not an overnight fantasy.


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## DawidvC (Feb 14, 2010)

m38mike said:


> y'know, this business of saving money with an EV is going to send me to the poor house!


Mike, see it as a learning experience. Then you can charge all these expenses to school fees. This way the education is expensive, and the EV cheap. (I think  )

Dawid


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## DIYguy (Sep 18, 2008)

m38mike said:


> Gary,
> I'd love to see pix of your gen/charger set up! That may be the best way for me to go, since the charger can monitor the pack condition and prevent itself from overcharging. If I used a simple bridge rectifier, I'd have to monitor the gauges constantly to manually prevent overcharging.


Hey Mike,

Since u asked...... (I realize it's not exactly what you need...but u may get something out of it....)
I started with this Rigid Gen-set. Capable of 7kw continuous over 8 peak. I just want to mention that if you buy something like this or larger.... don't buy a cheap model. This one has honda engine. Some folks have mentioned diesel...probably good advise. My point is... once u get what works... you don't need it dying on you!
One of the reasons I like this unit (other than the engine and output matching what I need), is this removable pendant. You can carry it with you (or mount it...or parts of it in your vehicle cabin) and have the remote start and remote power.. .but I wont bring the power as this is only 115volt circuit.
The cable shown is for remoting. edit... yes, there is also an hour meter and output indicator on the pendant...

Next post will detail my requirements for "mods" to this new unit.


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## DIYguy (Sep 18, 2008)

My intentions for range extending, are to carry this in the back of my Mazda B4000 pickup, under a tonneau cover... run it from propane and have remote start and stop inside the cabin.

First issue, is to loose the fuel tank. 

Next to strip weight. This is electric start with a battery. I think Ihave enough batteries on board without carrying one for this thing! 

One issue is that it is over 27" tall. I need it under 16.5 to fit under a tonneau nicely. More mods req'd.. 

Had to add a cross brace to support the heat deflector.

Next, I will shop for some smaller/lighter wheels...will need to mount them in a different location also...so they only engage the floor when unit tilted back....maintaining height. oooops, need some matching paint also!


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## DIYguy (Sep 18, 2008)

I also have to remount the controls....

Pick up a propane conversion....

The handle is easily removable as well.


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## m38mike (Dec 27, 2008)

DIYguy, 
very nicely done! That should make a very good range extender for you. I'm fortunate in that I don't have a height restriction for my trailer (within reason) because I plan to build a cover for it with panels that open to allow access to the generator and fuel, and spare parts. But your remake on that gen set looks very nice. I think that was a clever idea to use the 4-pin connector and cable to run your controls into the cab. I'll have to remember that.

Are you plugging this gen set into your regular on-board charger? What size charger are you using? At what speed will it keep up with your power requirements? 

Jimdear got me looking at propane generators again, and the more I look the more I like what I see. For weight, price, and performance they seem like a good deal. And since it'll be under a cover it will not matter what color or make it is. They save a bunch of weight over a similar capacity diesel gen set. And some are designed to operate on RV's while they are moving, so the idea of them bouncing around while it's producing power is less of a concern. If I plan to carry 2-3 days worth of fuel on the trailer, then I should be OK. I think I'll order a copy of Milepost so I can see where there is propane available. 

Thanks again for posting the pix and description!


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## DIYguy (Sep 18, 2008)

m38mike said:


> Are you plugging this gen set into your regular on-board charger? What size charger are you using? At what speed will it keep up with your power requirements?


Yes, I planned this before I started my conversion so I bought the charger with this in mind. Its an Elcon (aka Chinoz) 6 kw. Its 120/240 input compatible. This is why I bought the 7kw size gen-set.

I don't know at what speed it will keep up...it's more about average speed...or more importantly, avg current draw. I don't expect this will "keep up" at all. That said, it will extend my range... how much depends on the type of driving. For slower, city type driving...likely a significant amount. I also like the idea of carrying it on those "borderline" distance trips.

Im not sure what the terrain is like where u r going...but have you considered one of those swivel-wheel trailers? I really like the idea. It's one wheel (or u can get two wheeled ones also) and you don't have to steer it backing up... potentially lower drag maybe also..?? Lemme find a link for you....
here u go... http://www.cruiserlift.com/swivelwheel.html










or











...you get the idea. I was thinking of going this way at one point. Kind of pricey. Thought about making my own also. One important tidbit if you do..is the tire rating. Most small tires like this carry off-road or low-load specs. Have to make sure you get the right one for weight and speed.


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## m38mike (Dec 27, 2008)

Thanks for the idea. While those bumper mount trailers might work well in a typical application, one of my trailer requirements is that it is a military surplus trailer. This journey I will be on during August 2012 is hosted by the Military Vehicle Preservation Association. The convoy is all about driving old military surplus vehicles the whole distance. Part of that is my interest, since my jeep was a military jeep and so was my trailer. But a larger part of that interest for me is doing it using an EV power system. To see if I can really make it work, with the help of this forum, to create a long-distance range extender that anyone can copy. While not everyone would want to use a jeep trailer, the EV parts could be put on a Harbor Freight cheepo trailer, or the back of a pickup bed, or on a single wheel trailer like these.


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## JRP3 (Mar 7, 2008)

Nice job.


DIYguy said:


> Pick up a propane conversion....


Some questions, what did the generator cost?
How much will the propane conversion cost?
What does the generator weigh?
I've seen propane generators but they seem much more expensive than gas ones, I was thinking it might be cheaper to do a conversion they way you are.


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## DIYguy (Sep 18, 2008)

JRP3 said:


> Nice job.
> Some questions, what did the generator cost?
> How much will the propane conversion cost?
> What does the generator weigh?
> I've seen propane generators but they seem much more expensive than gas ones, I was thinking it might be cheaper to do a conversion they way you are.


$1,799 Canadian. (yes, you can buy similar output for a lot less $)

Propane - $157 USD....there are different options... high pressure, low pressure, duel fuel etc.

259 lbs full equipped. I will shed some of that... maybe get it to 200 + 20# propane tank.

It comes down to the quality u want in a gen-set. U can buy them for less than half of what I paid.... Princess auto had some already made for LPG .. I think the 6kw were about $800 if I recall correctly. I was tempted.


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## m38mike (Dec 27, 2008)

I was kinda thinking about a generator like this one.

http://cgi.ebay.com/Honda-Powered-1...32669202?pt=BI_Generators&hash=item35acd15f12

This would fit nicely in my jeep trailer and allow me to carry 4-6 propane bottles for fuel. Comes with a 2 year warrantee and Honda is a very good name in engines.


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## DIYguy (Sep 18, 2008)

nice.... the weight is actually very good for the output.


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## JohnM (Jan 12, 2010)

I think this is not an easy undertaking. The simplest way is to load the Willy's jeep in a trailer truck.


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## glaurung (Nov 11, 2009)

Hi JohnM
Simplest option is as always............stay home and watch tv  !

Interesting old ad i found.


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## m38mike (Dec 27, 2008)

Stay home and watch TV?? Load it on a trailer?? 

C'mon guys, where's your sense of adventure? Your entrapraneurial spirit? Your quest to do something different - just because you can? 

I've got to expand my horizons, challenge my pea-brained head, use up all my extra pennys, and see if I can create an adventure that's worth writing home about. That's what all this will be. A challenge, an adventure, a HUGE expense, an opportunity to drink gallons of coffee, and hopefully at the end of it all the chance to say "Yup, it worked!"


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## Jimdear2 (Oct 12, 2008)

m38mike said:


> C'mon guys, where's your sense of adventure? Your entrapraneurial spirit? Your quest to do something different - just because you can?


Mike,

"I'm bored to death I got to do something before I go nuts"

also works here.


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## DIYguy (Sep 18, 2008)

this has still got to be the best weight to output efficiency for a range extender. CroDriver found this originally some time ago.. he actually saw one in Germany if I remember correctly. How about 15kw for 8kg! or 30 kw for 19kg Incredible.

http://www.compact-dynamics.de/en/business-activities/e-mobility-electric-drive-systems.html

No idea of cost or availability....


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## DIYguy (Sep 18, 2008)

here's the original post...

http://www.diyelectriccar.com/forums/showthread.php?t=36606&highlight=GEnerator


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## DawidvC (Feb 14, 2010)

Now that is a nice-looking package. I had totally forgotten about small rotaries. Funny thing is, years ago I worked on small military gensets (about 4kw), that ran off a 375cc rotary (I have no idea what that would be in cubic inches ). The generator was much bigger than the rotary engine.

We use to see who could get their genset to run the fastest before we overhauled them ( easy on a rotary ) and we measured 27000rpm before turning chicken on occasion.

The whole genset was packaged in a square green box, and most of its weight was in sound-deadening. We used to tote the genset (without the enclosure ) singlehanded, so I guess it weighed about 25kg's (about 50pounds). Most of that is from the generator.

Excuse the rambling, but all I want to say is you could make one of those look like something military quite easy. The generator (motor) should be easy. Anyone know a source of small rotary engines (wankel )?

regards
Dawid


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## m38mike (Dec 27, 2008)

Jim,
my problem is that I have soo many projects going I will never be bored - EVER! 

DIYguy, thanks for those links! That would be so cool to have one of those units. I sent a request for info off to the company. We'll see what comes back.

I've been experimenting with different wire diagrams for figuring out how I should connect the gen set up to my vehicle. Based on the few rides I was able to make before my charger quit, I may be able to get down the road at about 40-50 amps for 30 mph. That's without a trailer. So I've been doing a little thinking and decided to post a possible set up for wiring in a generator and a heavy duty on-board charger to keep me going. 










I drew this up before I remembered that a Soliton has a contactor inside, so I probably would not need contactor 1. I thought I should have contactor 2 in line so I could disconnect the gen/charger power. One question I have is does it matter if I connect the gen/charger power to the first device out from the pack, or should I connect that power to the end terminals of the pack?

Are there any other suggestions for making this work?


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## DawidvC (Feb 14, 2010)

If you are running a BMS you might possibly want to use that to start and stop the generator - running a long downhill might see you overcharging the batteries. You could also stop, get out and handcrank it, if you want to


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## m38mike (Dec 27, 2008)

Well, I was hoping to get some comments on this wiring diagram, but no one posted any comments. So I guess either I've got it just right, or no one really cares how I wire it up. I'll go with the first idea. 










I'm talking with an outfit in Maine about generators. They have a good selection of both propane and diesel units that are injected. An injected engine is much more likely to keep running even when the trailer goes bouncing down the road.

I sold my Logisystem controller to another EV'er in the area. We installed it in his PU but he didn't have enough cable to finish the installation. We'll work on it again later. I'm waiting for payday to scrape up enough pennies to put a Soliton under my seat. I'm also hoping to get my charger back in the next week or two. They are supposed to get into it this week to see why it's not working. The guys at ElCon said once they get inside it should be repaired quickly.


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## JRP3 (Mar 7, 2008)

m38mike said:


> Well, I was hoping to get some comments on this wiring diagram, but no one posted any comments. So I guess either I've got it just right, or no one really cares how I wire it up.


I think the puffs of smoke from the genset confused us  Why the 2 contactors before the Solition? It has it's own built in. Also I think you should have the charger always connected to the pack, if it ever gets powered up without being connected it could blow the charger.



> They have a good selection of both propane and diesel units that are injected. An injected engine is much more likely to keep running even when the trailer goes bouncing down the road.


Would that matter with propane? I wouldn't think bouncing would affect it.


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## DIYguy (Sep 18, 2008)

Hi Mike, Sorry.... missed this for a while. Ya, I don't get the contactor function either. Connect the charger directly to the battery. 
Propane can keep an engine running in any orientation... that's why the rock crawlers use it.


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## DIYguy (Sep 18, 2008)

I was just thinking about your challenge here ... for a few minutes, and was thinking, there are kind of two ways to go. Either get a gen set capable of powering your ride continuously OR get a significant battery with a smaller gen set capable of "extending" your range so that you can attain your daily distance. 

If you go with the first option... you really don't need to carry all that pb weight around. Why not just have a small battery that can act as a buffer for the gen power? 

If you go with second option, I guess it is lots of lithium and a smaller gen set.

Either way, it kind of points to a different battery than what you have... yes/no??

Also, if your battery is a couple years old now, and this trip is in a couple years.... will your current battery be capable then?

At the end of the day, you probably want to be left with a vehicle that is "practical".... as I can't see you sinking all this money into this thing for one trip... yes/no??

Just some stuff to think about .... that was running around my coffee induced state this morning.... hehehe


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## m38mike (Dec 27, 2008)

JRP3 said:


> I think the puffs of smoke from the genset confused us


It's a throwback to the little engine that could!



JRP3 said:


> Why the 2 contactors before the Solition? It has it's own built in. Also I think you should have the charger always connected to the pack, if it ever gets powered up without being connected it could blow the charger.


You're right. I drew the diagram with my LS controller in mind, then relabeled it to reflect what I'd like to have. I'll have to check with Manzanita about blowing the charger if it's not connected. I know it'll shut its self down once the pack is charged up, but there may be times when I want to isolate the charger from the pack. I've been thinking about putting the charger in the trailer with the generator so I don't have to listen to the fans running all the time. 



JRP3 said:


> Would that matter with propane? I wouldn't think bouncing would affect it.





DIYguy said:


> Propane can keep an engine running in any orientation... that's why the rock crawlers use it.


That's exactly why I'm looking at gen sets with fuel injected engines. A carburated gas engine will not run smoothly while it's bouncing down the road in a trailer. Anything that's fuel injected will run smoothly, and at any angle too. That would mean I could take E-W with trailer out 4-wheeling in the mountains!! WOOHOOO!! 



DIYguy said:


> I was just thinking about your challenge here ... for a few minutes, and was thinking, there are kind of two ways to go. Either get a gen set capable of powering your ride continuously OR get a significant battery with a smaller gen set capable of "extending" your range so that you can attain your daily distance.


Or I could have the battery pack large enough to normally power me for my daily commute, AND have a gen/charger large enough to power me at road speed for long distances. I plan to use this jeep as my daily driver once I have all the bugs worked out. So the pack has to be big enough to handle that. AND I want to use it for the convoy to Alaska and back, so the gen/charger needs to be big enough to do that. That will also allow me to drive it other places as well, even to EV car shows to show folks that it can be done. 



DIYguy said:


> will your current battery be capable then?


I'm hoping it will, from an expense standpoint. I'm hoping it won't from an "ideal opportunity to upgrade" standpoint. I think that the hardest test for my pack will be my daily commuting, since I will be drawing them down considerably twice a day, and charging twice a day. I think the convoy trip will actually be easy on the pack since I expect the gen/charger to provide the majority of the power I need to move, while I'm moving. 



DIYguy said:


> I can't see you sinking all this money into this thing for one trip... yes/no??


Not just for one trip, No. For the long term capability? Maybe yes. Once I'm done with this trip, I hope to be able to use this setup to travel to other events. Of course part of my plan is to see if I can find sponsors to help with spare equipment, parts or supplies, or help with the bills. Would you like to have your name up at the top of my sponsor's banner???


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## DIYguy (Sep 18, 2008)

yes, I should have asked the question about your battery being capable when the trip rolls around, first.... then thinking, if you have to replace it....which way to go....


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## JRP3 (Mar 7, 2008)

m38mike said:


> I'll have to check with Manzanita about blowing the charger if it's not connected. I know it'll shut its self down once the pack is charged up, but there may be times when I want to isolate the charger from the pack.


I can't imagine why you'd need to do that, and certainly not when it's powered up. I think there is a way to have the Manzanita setup so that it won't blow when powered unloaded by limiting the max voltage capability. That of course limits your ability to change the voltage to a higher voltage pack in the future without sending it back, I think.


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## m38mike (Dec 27, 2008)

I'm looking at buying a propane generator, about 13.5kW from a dealer in Maine. When I talked with him, he said the generator is designed to run at a steady 3300 rpm. The throttle automatically adjusts the fuel to keep the generator running at that same speed. So it simply adjusts to compensate for the resistance it gets from the alternator. If it needs to produce 10w or 10,000w it just keeps spinning at 3300 rpm. 

Looking at the fuel consumption table for that gnerator here, that's not too bad for propane, and if I figure on say 40 mph average speed using over 75% capacity that's close to 30 miles per gallon for fuel. That's pretty respectable even if propane was powering the original engine instead of providing electric power to a motor.









When I was looking at the EV Consulting web site (www.evconsultinginc.com) in their article on hybridizing a DC system they claim that the typical EV should be able to maintain 50 mph using about 7.5kW on level ground. That 40 mph should take 5kW. My Electro-Willys Jeep is not as efficient, or aerodynamic as most EV's so I expect my power needed for the same speed will be much higher.


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## DIYguy (Sep 18, 2008)

I've just finished converting my 13 hp Honda/7kw genset to LPG. ... well, I just need to get a 10psi regulator for the propane bottle. I'll post a few pics soon. I managed to get the Rigid generator originally 27.5" tall down to just over 16" with wheels, and a whole lot lighter. This configuration will fit in the box of the Mazda pickup...eventually with a tonneau over it, hopefully muffling the noise somewhat.


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## JRP3 (Mar 7, 2008)

Have you considered modifying the exhaust to a better muffler system? I once built a tailpipe and rear discharge muffler for a lawnmower so that I wasn't driving through my exhaust all the time. Those little bolt-on-the-block briggs type mufflers suck.


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## DIYguy (Sep 18, 2008)

JRP3 said:


> Have you considered modifying the exhaust to a better muffler system? I once built a tailpipe and rear discharge muffler for a lawnmower so that I wasn't driving through my exhaust all the time. Those little bolt-on-the-block briggs type mufflers suck.


yes, actually... I have. I did some research on it also. It would seem that the muffler on this 13 hp Honda is already pretty good and the claim is that most of the noise is coming from the engine and alternator. My plan was to pipe a smallish resonator under the truck box and connect it to the existing muffler on the genset with a flex pipe. I may do some experiments first though... because I read a lot of threads (mostly from campers) who tried unsuccessfully to further quiet these units. I think the cheaper ones do use louder mufflers though. 
I almost did what you did with your lawn tractor...lol I have a rear engine zero turn Toro now.... love it!


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## JRP3 (Mar 7, 2008)

DIYguy said:


> I have a rear engine zero turn Toro now.... love it!


It's not electric


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## aeroscott (Jan 5, 2008)

m38mike said:


> I'm looking at buying a propane generator, about 13.5kW from a dealer in Maine. When I talked with him, he said the generator is designed to run at a steady 3300 rpm. The throttle automatically adjusts the fuel to keep the generator running at that same speed. So it simply adjusts to compensate for the resistance it gets from the alternator. If it needs to produce 10w or 10,000w it just keeps spinning at 3300 rpm.
> 
> Looking at the fuel consumption table for that gnerator here, that's not too bad for propane, and if I figure on say 40 mph average speed using over 75% capacity that's close to 30 miles per gallon for fuel. That's pretty respectable even if propane was powering the original engine instead of providing electric power to a motor.
> 
> ...


i setup a generator buy using a brushed pm motor from a small floor polisher . you close the cont actor spinning the hell out of the engine , move the throttle until you like the amps . very efficient , no regulator or a simple one (speed = volts / amps) and cont actor . I learned the concept on boats charging a battery bank . the company used truck alternators and a small diesel , they said it was more efficient to charge direct then go threw a generator/regulator , battery charger then into the cells . as i remember 12/24 volts alternator are not very efficient . So by going permanent magnet we get higher efficiency . I went with brushed motor ,very common and it starts the engine with out electronics . you can use brush less and add diode . Honda's inverter generators run pm brush less alternators with diode . I'm charging right now using a 5kw genset /charger and it's not near as efficient as my pm direct set .


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## m38mike (Dec 27, 2008)

DIYguy,
did you consider a sound-dampening box for your gen set? One of the ideas I'm considering for my trailer is to line the trailer box (36 x 72 x 18) with 1.5 inch egg-crate foam to dampen the sound. I'm also looking at an oversize baffle muffler to add to the existing muffler, then have a tail pipe exit through the bottom of the trailer. I'm looking at the extra muffler, and the downward tail pipe for limiting the sound from the exhaust. And I'm hoping that the egg-crate foam will dampen the engine and alternator sound to negligible levels. Just a thought.


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## aeroscott (Jan 5, 2008)

m38mike said:


> DIYguy,
> did you consider a sound-dampening box for your gen set? One of the ideas I'm considering for my trailer is to line the trailer box (36 x 72 x 18) with 1.5 inch egg-crate foam to dampen the sound. I'm also looking at an oversize baffle muffler to add to the existing muffler, then have a tail pipe exit through the bottom of the trailer. I'm looking at the extra muffler, and the downward tail pipe for limiting the sound from the exhaust. And I'm hoping that the egg-crate foam will dampen the engine and alternator sound to negligible levels. Just a thought.


 If you add to that foam from under the mats of a 240 Volvo (about 3/8" soft foam with a 1/8" of dense rubber lead filled ) cheap at pick and pull . these were good for the road rumble low frequency.they are heavy and rip easily .


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## DIYguy (Sep 18, 2008)

JRP3 said:


> It's not electric


yes.... but my son uses it to cut industrial lawns... like 4 - 6 hours at a time. Electric would last long enough... HOWEVER! I have a 6.5" ADC motor and a 36volt 400 amp Curtis for my old garden tractor.


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## DIYguy (Sep 18, 2008)

m38mike said:


> DIYguy,
> did you consider a sound-dampening box for your gen set? One of the ideas I'm considering for my trailer is to line the trailer box (36 x 72 x 18) with 1.5 inch egg-crate foam to dampen the sound. I'm also looking at an oversize baffle muffler to add to the existing muffler, then have a tail pipe exit through the bottom of the trailer. I'm looking at the extra muffler, and the downward tail pipe for limiting the sound from the exhaust. And I'm hoping that the egg-crate foam will dampen the engine and alternator sound to negligible levels. Just a thought.


Yes, I have some ideas along this line...but my intention is to put it in my pick up box an have a soft tonneau cover. I want to see how loud it is like this before doing more. What do you think??


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## DIYguy (Sep 18, 2008)

Before and after.....
Notice the LPG regulator in the one pic.


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## DIYguy (Sep 18, 2008)

JRP3 said:


> It's not electric


These should help ....


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## JRP3 (Mar 7, 2008)

Much better


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## todayican (Jul 31, 2008)

If this has been suggested already, I apologize in advance.

How about taking the ICE, mating it to an efficient electric motor, and getting it via pulleys to output something like "cruise volts and amps" at its most efficient throttle setting.

Then, at highway speed, have a switch that completely isolates the whole main electric system (batt pack, controller, etc) and have the ICE/Gen output go straight to the drive motor? One could modulate the speed of the vehicle with the ICE's throttle?


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## aeroscott (Jan 5, 2008)

just give it more gas , the batteries would work like caps , smoothing out the pulses . also take out some drop


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## Anaerin (Feb 4, 2009)

todayican said:


> If this has been suggested already, I apologize in advance.
> 
> How about taking the ICE, mating it to an efficient electric motor, and getting it via pulleys to output something like "cruise volts and amps" at its most efficient throttle setting.
> 
> Then, at highway speed, have a switch that completely isolates the whole main electric system (batt pack, controller, etc) and have the ICE/Gen output go straight to the drive motor? One could modulate the speed of the vehicle with the ICE's throttle?


Why would this be any more efficient than a mechanical link between the ICE and the wheels? (Clue: It wouldn't, which is why the Volt has a mechanical link between the ICE and the wheels for use at highway speed).


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## todayican (Jul 31, 2008)

Largely because there is no actual room to put a mechanical link in the trike I am building ;-)

Using AeroScott's suggestion though, If the ICE/Gen output was piped into the Batt bank and (assuming the max gen output was a) above the LVC and below the HVC Im guessing you could leave the ICE on during coffee breaks on a drive and be charging.

Im the first to admit im a total newb with ev drive systems, but would this work without an fancy systems to support it?


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## m38mike (Dec 27, 2008)

todayican,
I think you'd have some problems with overcharging your batts if you didn't monitor your ice/gen system constantly. No leaving it on during coffee breaks.


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## todayican (Jul 31, 2008)

M38, I have a dumb question (but thats how one learns) 

Lets say you have a batt thats max charge voltage is 3.7v and just for examples sake, lets say its Lifepo4 prismatic like a thundersky.

24 cells 2v low, 3.7 charge, 3v nominal = a pack that can range from 48v to 88.8v

Ok, now you have an Ice/Gen feeding in, say 75v x 75a
In my understanding the batts would never reach more then 75v for the pack?
What would happen if you did that all day?


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## aeroscott (Jan 5, 2008)

I would have a powered screw for the throttle . when voltage is hi/low the screw gets a signal to increase /decrease throttle . amps are just a function of voltage ( increase voltage the amps go up ) . but we still need a controller , which can start and stop the engine too, as a option


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## aeroscott (Jan 5, 2008)

Anaerin said:


> Why would this be any more efficient than a mechanical link between the ICE and the wheels? (Clue: It wouldn't, which is why the Volt has a mechanical link between the ICE and the wheels for use at highway speed).


 Its just simpler to build , engine can be placed to easiest or most strategic position . Mechanical is hard to beat for efficiency , but a pm would be closest second .


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## m38mike (Dec 27, 2008)

"Ok, now you have an Ice/Gen feeding in, say 75v x 75a
In my understanding the batts would never reach more then 75v for the pack?
What would happen if you did that all day? "

I don't know how TS LiFePO cells would respond since I haven't abused any, but if that was my FLA pack, I'd probably have acid all over the place. It's not just the 75v that your pumping into the pack, it's the 75a that the pack gets full of before long. That's why good chargers will taper off the amps when the pack gets to capacity. The Volts stay up there, but the amps just trickle in. That's called floating a charge. In your example your Ice/Gen is stuffing energy into the pack, and when the pack gets full it'll start to erupt if your ice/gen keeps it up. That's why you'd have to monitor what's going on all the time if you don't have automatic devices to do the monitoring for you. So don't go get a cuppa joe with that ice running large!! 

"Its just simpler to build..."
Simpler isn't always better...........It could be a lot more work on your part.


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## aeroscott (Jan 5, 2008)

todayican said:


> If this has been suggested already, I apologize in advance.
> 
> How about taking the ICE, mating it to an efficient electric motor, and getting it via pulleys to output something like "cruise volts and amps" at its most efficient throttle setting.
> 
> Then, at highway speed, have a switch that completely isolates the whole main electric system (batt pack, controller, etc) and have the ICE/Gen output go straight to the drive motor? One could modulate the speed of the vehicle with the ICE's throttle?


 Then if a DC motor(traction) you could drive it like a train even with a dead motor controller , dead voltage regulator ,dead battery bank . The dooms day survivor . Another point for brush motors .


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## todayican (Jul 31, 2008)

And now for the magic question:
What electric motor would be a good match with a 7hp ICE (Subaru Robin) if one were looking to put out 75v x Whatever the motor could muster for amps


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## aeroscott (Jan 5, 2008)

good question . the unit I put tougher is about the same engine or a little less . this is a 8 ish hp diesel but running at 1/3 power (1000 rpm) , 48 volt battery , 50 amps , the generator(motor) is rated at 24v and 35 to 50 amps , about 1 to 4 speed increase to gen so spinning 3000-4000 rpm . this gen could handle a lot more , more still with more fan . I'll find the weight ,etc.


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## todayican (Jul 31, 2008)

Which motor are you using for the Gen Scott?
Thanks.

Anyone know off hand what a standard Etec would put out and at what rpm in the 80v range?


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## todayican (Jul 31, 2008)

Well, construction on my Aero trike has begun  but the debate in my head over the drive line rages on lol.

I am pertty sure I will go with the 10hp chinese diesel for a few reasons:

Its cheap
It can burn bio
I should have some "headroom" at cruise speeds for a 12v alt and possibly even an ac compressor.

So the main question is, if my goal is to have the unlimited range a hybrid benefits from is

Serial or hybrid?

If I go serial, I can charge while at rest stops, and I have some freedom with motor placement, and possibly remove-ability of the whole gen.

If I go parallel I can drive the rear wheel via the diesel and a centrifigual clutch only for speeds higher then say 45 (highway)

Seems like I read somewhere that its not good to run an electric motor with no load. anyone smarter then me have any insights? The way I would do it is install 2 drive sprockets on the electric motor, 1 to drive the rear wheel, and 1 running up to the centrifigual clutch laden diesel.

when I want to use the diesel for range extention I would simply start it and it would add its hp to the party.

My best guess is the electric motor and drive system would think its going downhill?

Any gotchas hiding in this plan?

By the way, found a new motor on the scene, its a larger version of the etek with double brushes and a 500a for a minute and 150 cont: http://www.thunderstruck-ev.com/index.php?dispatch=products.view&product_id=135

How do you guys feel about using this motor to be the primary drive motor on a 1100 to 1200 (with people) trike with great aero and an "assist" motor helping out on the highway? (bearing in mind it would be asked for 70mph on its own from time to time)


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## m38mike (Dec 27, 2008)

todayican, how often do you expect to need the extended range? If you use it often, even daily, then going with a hybrid design might be best. If it's only occaisionally, like for a weekend drive, then serial is the way to go. Serial allows the prime vehicle to operate without the ice/gen, so saves some weight. 

That's why my design for the Electro-Willys will use a trailer to carry the generator/HV charger. When I don't need it, like daily commuting, I leave the trailer at home. I don't need to carry the extra weight. 

And speaking of Electro-Willys, I sold my Logi controller to another guy in town, and he's been very successful with it. He's been able to get up to highway speeds which he could never do with the Kelly controller he had. I'm still putting together my pennies to buy the Soliton1 that I want. I plan to get that before Christmas. 

I've got the military trailer that I will adapt for my generator trailer. It needs some work. I'll be doing some of that work over the winter to get it ready. I plan to get the generator and the Manzanita charger next spring.


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## JRP3 (Mar 7, 2008)

I'd lean towards serial myself. Easier configuration, good efficiency assuming most of your driving is on batteries.
That Etek might work, depends on your actual vehicle drag at speed.


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## michaeljayclark (Apr 3, 2008)

i have a 15000 watt single ac gebset.

ive been told to be able to go direct dc into the batteries i need a bridge rectifier. i found one that mouser has, i searched for a 200 amp rectifier and this one came up:

http://mouser.com/search/ProductDetail.aspx?qs=t7yjd2JO/gQxSyicVsTDzw==&cm_mmc=findchips

Manufacturer:	IXYS	
RoHS: Details	
Product:	Ultra Fast Recovery Rectifier	
Configuration:	Dual Parallel	
Reverse Voltage:	400 V	
Forward Voltage Drop:	1.54 V	
Recovery Time:	30 ns	
Forward Continuous Current:	100 A	
Max Surge Current:	1000 A	
Reverse Current IR:	1000 uA	
Mounting Style:	SMD/SMT	
Package / Case:	SOT-227B	
Packaging:	Tube	
Maximum Operating Temperature:	+ 150 C	
Minimum Operating Temperature:	- 40 C


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## m38mike (Dec 27, 2008)

That looks like it will work to feed your batteries. The one thing that makes me nervous about simply using a bridge between the generator and the battery pack is that the generator doesn't know when to quit feeding power into the pack, and the potential to overcharge is high. That'd do a lot of damage to most packs. That's why I prefer to have an automatic charger between the generator and pack. Something like a Manzanita charger. That's what I'm planning to put in my Gen-trailer. 

Hey some good news!!  My Soliton Jr arrived on Monday!  Now I'm studying the connections to see what I need to change in my current wiring, and waiting for the weather to warm up. It's -26 F this morning. Too cold for me to go mess with a controller in an unheated garage!


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## Woodsmith (Jun 5, 2008)

m38mike said:


> Hey some good news!!  My Soliton Jr arrived on Monday!  Now I'm studying the connections to see what I need to change in my current wiring, and waiting for the weather to warm up. It's -26 F this morning. Too cold for me to go mess with a controller in an unheated garage!


That's great news!

We need photos and a step by step of how it all fits in. Then you can grin your way through the performance reports.


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## michaeljayclark (Apr 3, 2008)

i was thinking the same thing, the bridge rectifier will just continue to feed feed feed...

so i thought well a dc to dc convertor that converts 144 volt dc to 12 volt dc limits the voltage to 12 volts.

i figured out bridge rectifying my 15kw generator will give me 216 volts dc or there abouts after the bridge rectifier... so the question is, will it just give the 216 and stop there when it sees the pack voltage at 216? the batteries when full should stop the charge... but they may not..

so how about a 216 to 200 volts? a traction pack at 200 is pretty good for a dc system. or even 216 to 144 which seems to be the most common pack size.


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## m38mike (Dec 27, 2008)

There is no feedback system going back through a bridge rectifier. There is no circuitry or way to tell the generator to slow down or shut off. It will continue to feed power unless there is a way to shut down the demand for power. Since battery packs can take in more power than they need, they don't do a good job of shutting down the demand for power. You need some type of intelligent circuitry to protect the pack and other items downstream. 

that's why high-voltage chargers are more convenient. They automatically monitor and adjust the charge rate. that adjusts the power demand from the generator. If you just have a bridge, you have to do the monitoring manually. That wouldn't work for me. I'd loose interest and fail to pay attention. Then I'd fry my pack.


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## michaeljayclark (Apr 3, 2008)

this circuit would really help is for electric start generators:

a circuit that monitors the pack voltage. When the pack drops below 144 the generator turns on and feeds voltage into the pack..

when the monitor circuit sees the pack voltage at 144 or a little higher it turns the generator off...

I know this is what a battery charge does however, we want the generator to shut down, not just go into an idle mode. in idle mode the generator is still burning gas. of course id rather be burning biofuels...

the switch on my generator is simple, hold to start then hold to shut off... of course this means i would need another circuit that will stop the switch that is turning the starter to stop the starter when the generator gets running...

maybe just a circuit that when it senses voltage it cuts of the power going to the starter to turn on the generator.


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## m38mike (Dec 27, 2008)

I thought I'd share a couple photos of the changes to Electro-Willys that I worked on this winter. The first photo is my new Soliton Jr in it's new position.  It's not a great photo because it was dark in the garage.









None of the cables are connected because it's too dang cold and they don't bend well when they're cold. I've got to drill some more holes in my floor to bolt down the Junior and my onboard charger. I hate doing that. Do you suppose duct tape and gorilla glue would hold them down OK?? 

This next photo show the heat cable and insulation at the bottom of my rear battery box.









The strips of duct tape keep the wires from touching each other and getting melted. It also lays the wires out in a pattern that focuses the heat on the outside ring of batteries, with limited heat wire for the internal batteries. The cable thermostat is visible just to the right of center.

Here's the rear battery box in place and loaded with 1,000 lbs of FLA batteries. 









The box is make from white oak for it's strength and to aid in insulating the batteries from the cold. The little black thing at the bottom of the box is the vent outlet. I've got a small computer fan that's manually switched that I use to ventilate the box. I'm thinking that when I hook up the generator and high voltage charger, I'll probably create lots of gas in here. 









This is the inside view of my vent fan. It'll push air in through this hole.


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## michaeljayclark (Apr 3, 2008)

Im liking it... well get the onboard generator figured out.


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## michaeljayclark (Apr 3, 2008)

I hooked up the bridge rectifier on the generator. I hooked it up to the 240 volt 50 amp output. It gave me 240 vdc. 

even did a little video. 

http://www.youtube.com/watch?v=8278sKjk7pM

next will be interesting to put a shunt to see the amps.


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## m38mike (Dec 27, 2008)

Thanks michaeljayclark,
I've been wondering what a full bridge rectifier would do for voltage, if it would remain constant or would it change. Now we know. I'm not liking the idea of pushing 240 vdc into my 144 vdc pack. This confirms my intention to put a high voltage charger between the generator and the pack. That way I don't have to worry about pushing too much voltage at any time into the pack. 

Thanks again for making and sharing that video.

Update on my progress with Electro-Willys; I've got all the parts I need now to install the cooling system for my Soliton Junior. The pack is all back in the boxes and connected. But my pack charger still is not working correctly. I had it repaired back in October, but I have not had it connected to the pack over the winter. When I tried to charge the pack a week ago, the charger kept telling me the batteries were too hot. Not likely since they were 28 degrees F. I disconnected the thermal sensor and it still gave me that signal. So it went back to the factory last week. I'll call them later today to see what the problem is.


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## michaeljayclark (Apr 3, 2008)

the generator has other outputs, even a 120 volt 30 amp output. I would expect it to output 120 volts dc and somewhere around 40 amps. looks like another experiment!

that would be fine for a 144 volt pack, since the generator is sending the voltage and not stopping I wonder if 120 vdc can charge up 144 vdc? I would think that it would send the 120 vdc and nothing higher.

BUT in this case having a constant 120 volts 40 amps going into the pack while you are driving is a good thing. I once asked mazanita micro about using the 50 amp charger with an onboard generator and I got a reply of yes, they just wont warranty the charger.

just rambling here but the 120 vdc coming out of the generator and not any more, the batteries would get 120 volts and no more, meaning they are not getting charged to 100%. 120 vdc of 144 vdc is 83%, that would mean that the batteries would only get charged to 80% which is a good thing, isnt it?

so we know only 120 vdc will go in, what about the constant charge of 40 amps? what happens there?


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## michaeljayclark (Apr 3, 2008)

Just thought of an idea...

we are trying to limit the current AT the generator. what if we limit the current AT the batteries??

solar panels send dc power and charge controllers are used to make sure the batteries the panels are charging do not get overcharged...

why not use a 12 volt charge controller per battery (if using 12 volt batteries no problem put if they are 6 volt then I see a need to convert 12vdc to 6vdc)? Ive read and the charge controllers can be paralleled to handle higher voltages/amperage. So if in my case since I have 26 6 volt batteries, the 240 vdc coming from the generator would be sent across the network of charge controllers. The charge controllers can handle 10 amps each, that would be more than enough to handle charging the batteries individually from the generator.

as an added bonus, you now have a direct DC charging system for your batteries. bridge rectify the current coming out of your 240 volt outlet in your garage and the charge controllers are battery chargers.

charge controllers = battery chargers

on ebay I see a simple little chinese made charge controller. looks like $15 each.


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## T1 Terry (Jan 29, 2011)

I think you will need to put the generator under load through the bridge rectifier to find out true DC voltage. Is the rectifier full wave or half wave? From the little bits I remember regarding diodes standard type diodes have a 0.7v drop at around 70% capacity and this can go up to 1.2v drop at over capacity. Stotchy diodes are about 1/2 this figure but you would need to build your own rectifier. Basically just 4 diodes on a heat sink. The tricky bit is calculating is only 2 diodes at a time are affecting the voltage so a 1.4v to 2.4v drop depending on load or if all 4 diodes affect the voltage so a 2.8v to 4.8v drop. 
now all this doesn't mean a whole lot at 240vac but at 120vac it starts to make a difference. If the voltage drop is 4.8v then you now only have 115vdc to play with, that's enough to charge a 96v lead acid battery pack but it wouldn't be enough to get anything into a 144v lead acid battery pack.
The basic logic path is a 12v nom lead acid batery requires 14.4vdc to charge effectively, 13.8 vdc will only maintain a charged battery bit it would barely trickly charge a discharged battery. There are 6 cells in a 12v battery so 14.4 divided by 6 = 2.4vdc per cell required for charging. There are 12 x 12vdc batteries in a 144v battery pack, 12 x 6 cells x 2.4v per cell = 172.8vdc required to recharge the batteries.
So now you need either a DC to DC converter that can handle *240VDC in and be adjusted to 173vdc out that can handle 40 to 50 amps 
or
12 DC to DC converters that can handle either *240vdc or *120vdc in and adjustable to 14.4vdc out at 40 to 50 amps. Now it's getting a bit more complicated with a heap more wiring and cable that can handle 50 amps.

*DC to DC converters usually have an input range like 200 to 250vdc or 100 to 150vdc, just random figures but the effect of the bridge rectifier doesn't need to be taken into account.

Hope this helped a bit

T1 Terry


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## michaeljayclark (Apr 3, 2008)

then we will have to look at the 240 50 amp outlet.

Ill test out the bridge rectifier with a load. the BF is rated at 33000 watts so it should handle 15000 watts without a problem.

I found those charge controllers and each one can take 12 volts and deliver 10 amps. If I wire 3 up in parallel does that means three will equal 36 volts and deliver 30 amps? I know this is an ideal number and there will be some loses somewhere.

If I added 13 together to get 156 volts, does that mean they can then deliver 130 amps? put this across 13 batteries would each battery get charged at 12 volts at 10 amps?


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## michaeljayclark (Apr 3, 2008)

I may have answered my question, instead of editing last post ill ask this:

the power source is 240 vdc at 100 amps. I take charge controllers that are rated at 24 volts, put them in series, I would need 10 of them to "suck up" the 240 vdc. each one can handle 10 amps, so each one would only "see" 10 amps?


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## T1 Terry (Jan 29, 2011)

michaeljayclark said:


> I may have answered my question, instead of editing last post ill ask this:
> 
> the power source is 240 vdc at 100 amps. I take charge controllers that are rated at 24 volts, put them in series, I would need 10 of them to "suck up" the 240 vdc. each one can handle 10 amps, so each one would only "see" 10 amps?


 The power source is now 100amps not 50 amps. As far as I understand it if the input is 100amps and the load sharing was even then 10amps per unit @24v would give 20amps at 12v, naturally there are losses involved but these are just rough figures. These unit would need a cut off when the battery is deemed fully charged but even as the batteries begin the reach the 80% level the amps will need to reduce to maintian the 14.4v at the terminal. The unit will no longer draw the full 10amps @ 24v, will this effect the 240vdc? If the load reduces will the voltage increase then requiring the units to accept more than 24v each? 
Maybe you would be better off looking at DC toDC converters designed to do the job

T1 Terry


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## michaeljayclark (Apr 3, 2008)

I have searched and googled and found charge controllers in parallel, not series... i dont think they would work in series.

I am trying to think of ways to do things with off the shelf parts.

dc to dc converters are there but higher amperage of 30 amps runs hundreds of dollars each.

just putting out ideas and looking for answers.

My next option to find someone who can modify the control board for my generator to get an output of 160 volts dc 30 amps. I have the bridge rectifier just need the voltage regulator that can handle high voltage.

I looked at just doing a charger for the string BUT nothing over 20 amps except manzanita micros $3000 charger.


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## m38mike (Dec 27, 2008)

michaeljayclark, you raise some interesting questions. I hope you will continue to investigate your line of thought. I'd like to know what you discover, so keep posting results. 

I kind of suspect that the right answer to absorbing a large power input and producing the correct power out for both charging and maintenance already exists in the form of Manzanita's high voltage chargers. There is some important circuitry included in them that I don't have the skills, knowledge or desire to duplicate. I haven't seen another charger on the web that can take the power-in that the Manzanita can. That's why I'm thinking that for my trailer project I'll want either the Manzanita 50 with the Buck upgrade or the Manzanita 75. Either one will give me 75 amps at 160 vdc. And as Terry has pointed out I need at least 152 vdc to get my 144 vdc pack to charge up. 

So if you were using a bridge to turn the AC into DC, and individual battery charge controllers to feed power to each battery, and you had the generator on a trailer, would you also put all the charge controllers on the trailer and simply feed a bundle of wires to the car for the battery connections? Or would you put all the charge controllers in the car, and just feed them from a single power feed?


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## michaeljayclark (Apr 3, 2008)

I appreciate the reassurance. I am sure some EE types have read this thread and said, "oh my god, they know nothing and are playing with how much voltage?!?!" I know because in another forum they told me to hang up the ideas before I kill myself.

I imagined the reason for a forum is to throw out ideas, based on electrical laws or just wild off the wall ideas, and the forum discusses them and the solution finally obtained. Then the information is able to be searched by google. I would love every book in the world scanned and put on the net, just think of the wealth of knowledge that would be available to all.

Now that I am looking at $3000 for a charger that can do what I have laid out, I actually posted a contract job on craigslist for someone to put an outlet on my generator that will deliver the 160 vdc at 30 amps. Or just a box that connects to the 240 vdc 30 amp outlet. What I am looking for is a big alternator basically. 

Ive seen charge controllers that can handle the voltage I am going to put through them. Generators are used in the solar world to keep a bank of batteries charged for off grid systems. I think what we are doing here falls into that category, we are trying to do the same thing.

A combiner box gets the voltage down to 48 volts or lower that then is fed into the charge controllers. I could charge 8 6 volt batteries BUT the charge controller that delivers 30 amps would be split among all the batteries. A 60 amp 12 volt charge controller is $500. A 50 amp charge controller is $100.

there must be a point that is crossed when you go from 50 amps to 60 amps because the price jumps dramatically.

So, my conclusion without spending $3000 is to have a box that acts like an alternator and delivers the 160 VDC from the generator.


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## m38mike (Dec 27, 2008)

I hope you can reach your conclusion without spending $3000. I'd be very interested. But from my low level of knowledge, and desire to keep living, I think the smart money is to pay for a charger that can take the high voltage and process/manage the output vdc to match what your EV needs. Some smart EE's already invented the circuitry to solve our problem, an I'll invest in their product. 

But if you find a way to make it work for less, Man, I'm on your band wagon!


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## michaeljayclark (Apr 3, 2008)

quickcharge.com

i have a charger from them and it works well. it plugs into a 240 volt 30 amp outlet.

i wonder if they can make a 240 volt 50 amp charger?


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## m38mike (Dec 27, 2008)

They have some heavy duty chargers, but you need to be careful about what they provide for vdc out. For instance, I did not see in any of their tables where they have a charger for a 144 vdc system. I didn't spend much time looking, but if all they support is up to 120 vdc, then they don't have a product that will support my EV.


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## HYPRDRV (Aug 20, 2009)

Hi Mike,
I thought I would give you a little info on my "Hybrid". I own a 41' Catamaran that incorporates a 15kw genset produced by a German company back in 04. I read somewhere in the string a German company mentioned but no name. My genset was manufactured by HFL who now doesn't produce the large gensets. The genset outputs 240v rectified to 144v which is wired directly to a buss bar that feeds the 12 batteries. I have an adjustable voltage output which I set to 160-164v DC and an amp gauge I use to monitor the output of the genset. All of this manually however most Marine gensets are starting to go auto-start/shutdown and I know of at least 2 companies going direct DC to DC with this feature. Fischer Panda is one and Northern Lights is the second. I mention this because they do exactly what your looking for in a package. That's the good news, the bad news is you can figure about $1000 per KW (or higher). I consider the FP unit to be state of the art at this point but take a look at the Marine industry for ideas. 
As far as chargers go I have a Brusa NLG5 that I'm thinking of selling because it doesn't step back to it's previous program. Unlike a car I can have loads at the dock that exceed the maintenance charge. I'm looking at the Zivan. I look forward to reading about your final setup, I don't pretend to understand 1/2 of what the posters here have said but I'm learning so it's a good thing.

Steve


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## m38mike (Dec 27, 2008)

Steve, Thanks for the names of those generator companies. I checked both of them out. Very nice generators for big trucks or boats. But at 750 lbs and up for a 12 Kw gen set without fuel tank or battery, it's a bit too heavy for me to use. And while I like diesels because you can run them on waste vegetable oil, they are just too heavy for EV applications. Great for stationary charging though. In looking hard at the weight of a 12 kw generator, the lightest one I've found is made in Maine using a Honda 20 hp gas engine. It comes in at 235 lbs without the starter battery or fuel tank. With a 30 gallon fuel tank (which I already have, so no expense) and a 12v deep cycle battery to start it, I expect the whole package to weigh in at about 500 lbs. Add a high voltage charger, some cabling, some plumbing for the fuel, some bracing and mounts and I'm up to 600 lbs for the whole package. 

That's not too bad for a package that can produce 12,000 watts for almost 20 hours continuously. And 12kW will move most EV's down the road at highway speeds I suspect. I don't think it'll do that for Electro-Willys. With the aerodynamics of a stack of bricks, and a drive train that's designed for rugged, not for racing, I'm going to feel lucky if I can sustain 40 mph on 12 kW. 

I've got Electro-Willys all put back together with my new Soliton Jr on board, and it's ready to do some road testing except for one thing. My laptop is not talking with the controller. I have not been able to program the Junior for my system and I think it's because my laptop is jealous.


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## HYPRDRV (Aug 20, 2009)

Mike I just wanted you to see that there is some stuff out there, may not be the right stuff but it's available and some pieces could be used.
Good Luck
Steve


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## BandDButton (Oct 15, 2009)

After reading this thread I'm a little confused. Is the idea to use the generator to power an on-board charger, or to rectify the current and feed it directly to the batteries? Personally I like the idea of powering a charger, to keep the batteries happy.


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## JRP3 (Mar 7, 2008)

Both ideas have been discussed. Seems easier and safer to use the genset to power a charger, probably costlier in most cases though.


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## m38mike (Dec 27, 2008)

JRP3 is right. Both ideas are out there. Both are doable. But some of the considerations that we've voiced have been expense, technical ability, compatability with our systems, how much is automatic, how much is operator managed. I have appreciated all of the discussions because they have helped me settle on the system that I think will work best for me. That being a generator and high voltage charger. More automatic is better in my book. 

We've occasionally heard about others with similar systems, but I don't think anyone has really stepped up and demonstrated quite what I'm proposing to do. My intent is to make this discussion a reality so that others can learn from it and repeat it, or modify it to suit their needs.

On the good news front, I solved my mistakes in getting my laptop to shake hands with Junior, the controller, and I was able to get Junior configured for Electro-Willys. Now I'm ready to start my power testing this afternoon after work. I'll try to remember to get some photos posted along with some of the data.


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## Anaerin (Feb 4, 2009)

BandDButton said:


> After reading this thread I'm a little confused. Is the idea to use the generator to power an on-board charger, or to rectify the current and feed it directly to the batteries? Personally I like the idea of powering a charger, to keep the batteries happy.


_If_ the power coming out of the generator is at the correct voltage for the pack, you _can_ directly rectify it into the batteries. *However*, your EV is _also_ going to be plugged into the wall to charge, which means you need a charger to up/down/round convert the wall voltage (110/220/240/415v AC) to pack voltage. As you already have to carry a charger, why not use that charger with the generator, as well as with the wall? It reduces complexity and simplifies the build.


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## m38mike (Dec 27, 2008)

Anaerin said:


> *However*, your EV is _also_ going to be plugged into the wall to charge, which means you need a charger to up/down/round convert the wall voltage (110/220/240/415v AC) to pack voltage. As you already have to carry a charger, why not use that charger with the generator, as well as with the wall? It reduces complexity and simplifies the build.


Because that on-board charger is not big enough to keep up with the power requirements of moving down the road. It's not a "high amp" charger. I could replace the PFC 1500 with a high voltage Manzanita as my on-board charger. But I also have the issue of space in that little jeep.


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## Anaerin (Feb 4, 2009)

m38mike said:


> Because that on-board charger is not big enough to keep up with the power requirements of moving down the road. It's not a "high amp" charger. I could replace the PFC 1500 with a high voltage Manzanita as my on-board charger. But I also have the issue of space in that little jeep.


So, instead of _replacing_ your low-amperage charger with a slightly larger, high amperage one, you want to *add* a high-voltage, high-amperage rectifier with step down and smoothing (Essentially, a high-amperage charger) to the low-amperage charger that's already on-board. And this will solve the issue of space you have?


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## m38mike (Dec 27, 2008)

Anaerin said:


> So, instead of _replacing_ your low-amperage charger with a slightly larger, high amperage one, you want to *add* a high-voltage, high-amperage rectifier with step down and smoothing (Essentially, a high-amperage charger) to the low-amperage charger that's already on-board. And this will solve the issue of space you have?


Yes, because the high voltage charger will be in the trailer along with the generator. That's what this thread is about, making a trailer that will allow me to travel extended distances. When I don't need it, I disconnect it and travel with just the jeep. The smaller, on-board, PFC 1500 does OK for daily short trips. That makes the trailer a complete package and capable of supporting anyone's EV. That's the concept I'm trying to achieve.


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## m38mike (Dec 27, 2008)

I got the Electro-Willys running again yesterday and decided to take it out for a test drive. I programmed the Soliton Jr with some conservative settings to start out. I wanted to see just how zippy it'd be with mild settings. Not bad! Got it up over 50 before my lips started flapping in the breeze. 










In fact it was going so well I decided to really give it a test. I hooked up one of my trailers with some firewood in it to simulate the weight it'll have to tow when I build the generator trailer. Here's a shot of me getting ready to leave on my first road test with the trailer.










The green tank on the back fender is part of the controller cooling system I built to keep my Junior from flaming out like the last one did. I was not as impressed with the jeep's performance hauling this trailer. I also noticed that I was using a lot more electric power trying to pull up hills. Even shifting gears down didn't do much to help. So now I need to reset the controller settings to something a bit more agressive. And sometime soon I hope to have the new windshield frame mounted so I can leave the goggles home! 

I also found that my tachometer was not working all the time, so I've got to get into the wiring to see if something is loose. I guess my next step is to download the Soliton data recording program, and then hook up my laptop to the Junior while I'm out pulling the trailer to see what my power use is. I think that'll be better than me trying to read my gauges and taking notes while I'm driving.


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## Tesseract (Sep 27, 2008)

m38mike said:


> I got the Electro-Willys running again yesterday and decided to take it out for a test drive. I programmed the Soliton Jr with some conservative settings to start out. I wanted to see just how zippy it'd be with mild settings. Not bad! Got it up over 50 before my lips started flapping in the breeze.
> ...
> In fact it was going so well I decided to really give it a test. I hooked up one of my trailers with some firewood in it to simulate the weight it'll have to tow when I build the generator trailer.
> ...
> I was not as impressed with the jeep's performance hauling this trailer. I also noticed that I was using a lot more electric power trying to pull up hills. _Even shifting gears down didn't do much to help_.


Well, what were those mild settings?!? 

The sentence I italicized indicates that you might have the battery current set too low, btw. You need *power* to go up mountains, especially when towing a trailer. A Junior won't accelerate as fast a Soliton1, but it should have more than enough power capability for this application. 



m38mike said:


> I also found that my tachometer was not working all the time, so I've got to get into the wiring to see if something is loose....


What kind of sensor are you using for the tachometer?


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## m38mike (Dec 27, 2008)

Tesseract said:


> Well, what were those mild settings?!?


I was operating in the "quiet" mode instead of the "performance" mode. Although I couldn't tell just how quiet it really was, with all that wind whistling past my ears! But I know I definitely need to put more zip into this EV if I'm going to pull a trailer.



Tesseract said:


> The sentence I italicized indicates that you might have the battery current set too low, btw. You need *power* to go up mountains, especially when towing a trailer. A Junior won't accelerate as fast a Soliton1, but it should have more than enough power capability for this application.


 I think I've got the maximum battery current set to 400A, so you could be right. Given that I've got 18 8v 165ah FLA batteries, what would you recommend? BTW, my other settings are as follows:
Min batt voltage = 126
Max motor voltage = 170
Max motor current = 500A
Max motor power = 85 kW
Slew rate = 500 A/s

I've got a WarP11 but I haven't found some of the limits the controller needs set. If you know what they are please tell me. 



Tesseract said:


> What kind of sensor are you using for the tachometer


I've got a Westach tachometer and I'm using a magnetic pickup on the motor's tail shaft. Where I might have caused part of the problem is by having 3 different tach sensors trying to read from that single signal. I've got the tach gauge, the Junior, and a 3rd sensor that trips rpm based switches.


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## Tesseract (Sep 27, 2008)

m38mike said:


> I was operating in the "quiet" mode instead of the "performance" mode.


That's not going to make much difference in total power so I'd keep it on Quiet mode because it will reduce the amount of ripple voltage reflected back to those poor flooded lead-acid batteries.



m38mike said:


> I think I've got the maximum battery current set to 400A, so you could be right. Given that I've got 18 8v 165ah FLA batteries, what would you recommend? BTW, my other settings are as follows:
> Min batt voltage = 126
> Max motor voltage = 170
> Max motor current = 500A
> ...


The maximum power the Junior can deliver continuously is around 150kW, but that requires a 300V nominal battery pack. With a 144V battery pack - limited by the controller to delivering a maximum of 400A - you have, at best, 57.6kw/77hp on tap. That's not a lot of power to work with for a road-going vehicle, particularly one that is hauling a trailer up mountains.

As I said in an earlier response to you:



Tesseract said:


> ...Junior should be a good fit for your vehicle, depending on how much heavier than stock your Willys is now. That said, it would be a much better fit if paired with a reasonably high voltage lithium pack (240V+) and a good Kostov motor wound for high voltage. A standard 36/48V 11" motor isn't going to have an ideal tradeoff between volts and amps for Junior but it shouldn't be a disaster...


I just don't think lead-acid batteries, especially the flooded type, are going to cut it here. The motor and controller are almost irrelevant at this point.



m38mike said:


> I've got a Westach tachometer and I'm using a magnetic pickup on the motor's tail shaft. Where I might have caused part of the problem is by having 3 different tach sensors trying to read from that single signal. I've got the tach gauge, the Junior, and a 3rd sensor that trips rpm based switches.


We have heard of similar problems from other customers. My guess - not having any direct experience with this, mind you - is that an automotive tach is looking for a signal from an ignition coil, whereas the Soliton1/Junior is looking for a nice clean pulse from, e.g., an industrial proximity sensor. You probably need to use two different sensors here - an industrial prox for the Junior and whatever the Westach comes with for it.


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## m38mike (Dec 27, 2008)

Tesseract said:


> That's not going to make much difference in total power so I'd keep it on Quiet mode because it will reduce the amount of ripple voltage reflected back to those poor flooded lead-acid batteries..


I'm not sure I understand what you mean by "ripple voltage". Can you expand on that a little? 



Tesseract said:


> The maximum power the Junior can deliver continuously is around 150kW, but that requires a 300V nominal battery pack. With a 144V battery pack - limited by the controller to delivering a maximum of 400A - you have, at best, 57.6kw/77hp on tap. That's not a lot of power to work with for a road-going vehicle, particularly one that is hauling a trailer up mountains..


I limited it to 400A just as a starting point. I see an evaluation here, but not a recommendation. Do you see any problem with me increasing this to 600A? And with 77hp available at 400A, I'm already doing better than the original ICE since it was only rated at 60 hp. 




Tesseract said:


> I just don't think lead-acid batteries, especially the flooded type, are going to cut it here. The motor and controller are almost irrelevant at this point..


I would love to replace the FLA with LiFePO, but it's not in the budget for the near term. That's $10K+ I don't have. So my challenge is to make the best of what I do have. The motor is the motor. Not much to adjust there, but past performance has shown it to be a powerhouse in this small jeep. So now I need to make the best of the settings in the controller so that it is "relevant" to getting the best possible performance from my EV. My inclination is to raise the limits in the Junior and simply let the batteries set the limit on how much energy is available to the motor. 



Tesseract said:


> We have heard of similar problems from other customers. My guess - not having any direct experience with this, mind you - is that an automotive tach is looking for a signal from an ignition coil, whereas the Soliton1/Junior is looking for a nice clean pulse from, e.g., an industrial proximity sensor. You probably need to use two different sensors here - an industrial prox for the Junior and whatever the Westach comes with for it.


The tachometer solution may very well be to put all tach's on their own sensor. I will start by disconnecting the Junior and the other tach from the Westach proximity switch and see if that improves the Westach performance. Do you have a recommendation for a sensor that works well with the Junior? 

I do want to say that with the Evnetics throttle I thought the the controller response was smooth and steady. It pushed the jeep forward with authority. It pushed power quickly to the motor. I have not yet tried to spin the tires on gravel so it'll be interesting to see if I can. I appreciate your working with me to help with matching the Junior up to my EV to make it the best that it can be.


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## Jimdear2 (Oct 12, 2008)

Mike and Tess,

I'm pretty ignorant here but something caught my eye. You show you've set minimum battery voltage at 126. Fot the Jr. is that the voltage point when it will start cutting back on current to keep the voltage up? 

I got caught that way with my Alltrax when pulling, I couldn't understand why I just couldn't put any current into the motor. 

If it is I would think you would want that a bit lower. Let the voltage (Speed) sag down for those hard runs and keep the torque (current) up. You can always watch your instruments and back off the throttle if something gets too out of shape.

I hope I'm not wasting your time.

Jim


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## m38mike (Dec 27, 2008)

Jim, it's all good discussion so no wasted time there. I was wondering the same thing. That's a sag of only one volt per battery, and it seems to me I remember the pack sagging more than that when I had the Logisystem controller. Yeah I wonder if I'm limiting myself too much with that. 

Question is if I were to allow two volts per battery and go to 108v, am I opening up the pack to any damage?


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## Jimdear2 (Oct 12, 2008)

Mike,

Don't take this information as gospel, but I believe I read that for short duration (I don't know how long) a good battey can sag 1/2 it's rated voltage and for longer sessions I think it was 1/3 ot 1/4 of the rated voltage.

Don't forget that you loose a lot to Peukert when you pull big amps.

One thing, you might start the generator for long hills. The charger might keep the voltage in the pack higher, even a few volts will help.

Best bet is to get some of the Pb battery experts to answer the sag voltage question.

Remember the controller limits are for emergencies, your foot is the real control.

Jim


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## JRP3 (Mar 7, 2008)

My method would be to take off the limits and see what the pack can give you for testing, then dial it back to what you can reasonably live with while still preserving the pack. Obviously keep an eye on voltage while testing.


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## Tesseract (Sep 27, 2008)

m38mike said:


> I'm not sure I understand what you mean by "ripple voltage". Can you expand on that a little?


I can, but it's bound to make your eyes glaze over. Motor controllers draw current from the battery pack in pulses. The input capacitors - and the batteries themselves - integrate that, in conjunction with their internal resistance - into a triangular voltage waveform, or ripple. Worst case occurs at 50% duty cycle (ie - any time battery current is half that of motor current) and maximum motor current. FLA batteries have relatively high internal resistance compared to other types (much higher than AGM, not as high as gel-cells, however). 



m38mike said:


> I limited it to 400A just as a starting point. I see an evaluation here, but not a recommendation. Do you see any problem with me increasing this to 600A? And with 77hp available at 400A, I'm already doing better than the original ICE since it was only rated at 60 hp.


You're asking some questions that I can't possibly answer for you. Realize that the more current you pull from your batteries the fewer the number of cycles you'll get out of them - how much is that trade-off worth to you?

And, yeah, your jeep might have more power than it did with the original ICE, but it also weighs a lot more now because of the batteries and you've hitched a trailer it. Boosting the battery current limit to 600A will give you a peak power of ~115hp which will likely be very noticeable, but it's going to be pretty rough on those 165Ah FLAs. I really wouldn't go over 3C (500A is close enough) with those cells, and even then I wouldn't want to do that for long.



m38mike said:


> I would love to replace the FLA with LiFePO, but it's not in the budget for the near term....


No problem, and completely understandable, just keep their limitations in mind. If you could cram one or two more 8V batteries onto the jeep that would help the whole pack immensely, though, by lowering the average current required. 



m38mike said:


> The tachometer solution may very well be to put all tach's on their own sensor. I will start by disconnecting the Junior and the other tach from the Westach proximity switch and see if that improves the Westach performance. Do you have a recommendation for a sensor that works well with the Junior?


The existing RechargeCar "Warp Speed Sensor" works well IF you remove two of the set screws from the collar that the sensor detects (ie - change it from 4 pulses per revolution to 2 ppr). We personally like to use inexpensive inductive proximity sensors from, e.g., Automation Direct (Seb at evnetics is the guy to ask about this and other implementation applications, btw).

Oh yeah... I agree that you probably have the minimum pack voltage set too low. 1.8V per cell is usually pretty safe. While maximum power from a battery pack (or any other power source) occurs when its voltage has sagged by 1/2 (ie - internal resistance and load resistance are the same) this is very abusive to the batteries. Ok for drag racers, not really appropriate for daily drivers!


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## m38mike (Dec 27, 2008)

Thanks Jeff, I appreciate your helping me understand the consequences of some of my possible actions. I think I'll enjoy experimenting with some of the settings to see what the change will do for performance. Actually it's just a great excuse for simply taking more rides!! But hey, if I can learn more about what my machine can do, it's worth it. 

Jim and JRP3, Thanks for the ideas. I'm thinking of going there, but slowly.


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## m38mike (Dec 27, 2008)

I adjusted the settings on the Junior to broaden the range of performance and it made a big difference in how the jeep responded. I'm very happy with how it's working now. 

But I noticed something unusual with my tach. I have an electronic one with a magnetic proximity sensor mounted near the front of the motor. There's a plastic collar on the front shaft that has 2 magnets in it to make the proximity sensor work. But here's the problem. When I'm accelerating the tach goes to zero. When I'm holding my speed steady the tach goes to 1000 rpm. When I completely back off the accelerator, the tach shows me the true motor rpm. I'm not sure what's happening here, but I think that when I put power to the motor, it must have a strong magnetic field that is affecting the sensor. I'm looking for suggestions on how to fix this problem.

Any ideas???

I also noted while I was driving that at 30 mph I was using about 3.2kW and at 50 mph I was using about 5.6kW according to my Cycle Analyst. Once I get my laptop defragged and ready to copy data, I plan to connect it to Junior while I'm driving so I can capture the data that Junior will tell me about performance and power use. I'm interested in comparing what Junior will tell me and what the Cycle Analyst tells me. That will go a long way toward helping me decide just how much generator I need to buy to power up the Electro-Willys Range-Extender trailer.


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## m38mike (Dec 27, 2008)

I solved the tach problem! I moved the tach sensor about an inch farther away from the motor, then I put a steel plate between the tach sensor and motor. When I took it for a very chilly test drive this evening, the tach worked perfectly. I really like it when a plan comes together! 

Now I'm going to hook the contoller back up to the tach sensor and then connect the laptop to the controller to find out if the controller is getting the tach signal.


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## hijibs (Sep 10, 2012)

hi
i am new to this... but i have read through ur previous posts on EVs using batteries only.
Now this one i suppose is using generator only...
but as i understand while we are using the batteries we are limited by the size and cost of batteries...
y cant we try generator as a supplement to batteries? so that we use batteries for start and acceleration and generators otherwise for normal running...
i've also read that AC motors have better performance characteristics over DC motors...


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## Anaerin (Feb 4, 2009)

hijibs said:


> hi
> i am new to this... but i have read through ur previous posts on EVs using batteries only.
> Now this one i suppose is using generator only...
> but as i understand while we are using the batteries we are limited by the size and cost of batteries...
> ...


Congratulations, you've invented a Series Hybrid. See also: The Chevy Volt.

You certainly can use a generator to supplement batteries, but using a generator is nowhere near as efficient as replacing the weight of the generator with more batteries and charging them from the wall, and while it may get you greater range, it comes at the cost of extra weight and greater costs for fuel. There is also the matter of the much greater added complexity, as you have to have a battery management system that can handle power in and power out at the same time, a generator large enough to be able to power the vehicle, and a charger big enough to convert the AC current you'll get from your generator into suitable DC for the batteries whilst being able to handle the power necessary to move the car. 

In some cases, for instance for very long journeys, it might be that a generator is a good idea, perhaps in a towable trailer of some form, to extend your range. The advantage then becomes that when you don't need the extra weight of the generator, while you're commuting for instance, you don't have to take it with you. It also means you could use it for backup power generation at home, for instance.


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## madmike8 (Jun 16, 2011)

Ok, question. If I had a 24 Lifepo4 cells. Could I get 3 Meanwell RSP-3000-24 Power Supplies Link aNd run them in series set at ~3.45v per cell. Use that with a generator on a trailer for a hybrid? Am I making any sense?


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## Anaerin (Feb 4, 2009)

madmike8 said:


> Ok, question. If I had a 24 Lifepo4 cells. Could I get 3 Meanwell RSP-3000-24 Power Supplies Link aNd run them in series set at ~3.45v per cell. Use that with a generator on a trailer for a hybrid? Am I making any sense?


Yes, you are. But I see a problem. Those three supplies would need to be connected in series, which is more than likely not possible, and you'd be trying to overdrive them anyway (24 cells / 3 = 8 cells per supply. 8x3.45v = 27.6v. The power supplies produce 24v. 4 supplies would work quite nicely, and give you a little voltage overhead (24(cells)/4 = 6, 24v/6 = 4v each cell)). And you would have 3kw to run the vehicle from. Most small vehicles require at least 9kw just to run on the straight and flat, with no charging capacity beyond that. And that's not even taking into consideration the generator itself.

So yes, it'd make a series hybrid, but all you would be doing is slowing your discharge rate on the batteries by about a third.


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## hijibs (Sep 10, 2012)

Thanks Anaerin for ur reply... as u suggested a generator powered EV will have a greater range.... lets take this case u have a EV that runs purely on batteries, now if u have a generator that can keep charging the batteries as they are consumed, i guess we would be better off. Especially when one is waiting in long traffic jams and ur car is just inching forward... with the generator(running on petrol or diesel) u can store all the energy in batteries unlike the case with IC engines which waste energy while ideling... wot do u say?


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## Anaerin (Feb 4, 2009)

hijibs said:


> Thanks Anaerin for ur reply... as u suggested a generator powered EV will have a greater range.... lets take this case u have a EV that runs purely on batteries, now if u have a generator that can keep charging the batteries as they are consumed, i guess we would be better off. Especially when one is waiting in long traffic jams and ur car is just inching forward... with the generator(running on petrol or diesel) u can store all the energy in batteries unlike the case with IC engines which waste energy while ideling... wot do u say?


Okay, yes, that would work. Of course, the extra weight of the generator and fuel would bring down the efficiency of the vehicle, as it's a fair amount more weight to move around, which would mean you'd have to use more power to accelerate and keep the vehicle at speed. Or you could just not include the generator, add batteries in the space where the generator was going to go, and get extended range that way, for less work and less pollution. 

Do remember that electric motors don't idle, so while you're sitting at the lights you're not using any power. And while this would generate a little power in a few minutes you're stationary, it wouldn't be enough power to justify carrying around all the extra weight.


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## madmike8 (Jun 16, 2011)

I'm not really looking for efficiency. Since I'm looking at a needed range for my daily driver of <15 miles. I'm building my EV with only a 30 mile range. Maybe twice a year I might want to take it ~250 miles to an EV event or something, and at that point I'd like to pull a trailer that would extend the range between charges. I wouldn't even mind if I had to stop for an hour or two to charge every hundred miles or so. It would give me a chance to stretch my legs and grab a bite or something. The generator would be multi purpose for me (emergency power, camping, etc.) where a trailer full of batteries wouldn't. I'm just trying to figure out the best way to do it at an affordable price.


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## Duncan (Dec 8, 2008)

madmike8 said:


> I'm not really looking for efficiency. Since I'm looking at a needed range for my daily driver of <15 miles. I'm building my EV with only a 30 mile range. Maybe twice a year I might want to take it ~250 miles to an EV event or something, and at that point I'd like to pull a trailer that would extend the range between charges. I wouldn't even mind if I had to stop for an hour or two to charge every hundred miles or so. It would give me a chance to stretch my legs and grab a bite or something. _*The generator would be multi purpose for me (emergency power, camping, etc.) where a trailer full of batteries wouldn't.*_ I'm just trying to figure out the best way to do it at an affordable price.


Hi Mike
Why would the generator be multipurpose and the batteries not?
_*emergency power, camping, etc.
*_Batteries would be just as good _*- 

*_enough energy to take you 250 miles_* - *_at 300watthours/mile = 75KwhrsThat would run my house for over a week! - or a big freezer for 6 weeks!


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## MN Driver (Sep 29, 2009)

Duncan said:


> 75KwhrsThat would run my house for over a week! - or a big freezer for 6 weeks!


75kwh would be enough to run my house for over half a month for 9 out of the past 12 months of actual electricity usage. Remove the air conditioning load and there isn't a month that I couldn't run my house for half a month.

Of course then you'd be driving a gas car around to save the range on the trailer pack if you thought the outage would be extended or driving far enough with your trailer to plug it into a J1772 where there actually is power to top up when there is an outage that lasts an extreme amount of time.


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## madmike8 (Jun 16, 2011)

We had tornadoes down here a couple years back. No power for 3+ months... just saying... 

Either way... I'm not doing a trailer full of batteries... too expensive(Lifepo4) or too heavy(Lead)... Don't think fullsize car here... My car will weigh ~1000lbs total when done. I won't be driving at freeway speeds. All back roads <=50 mph.


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## raszpel (May 19, 2010)

MadMike8 I have been following your thread with great attention. I am working on a range extending/portable charging system also. I own a 1980 Commuta Car, you know those little wedges. I have a 60 volt pack with an altrax controller. I do not have the volt and amperage levels needed that you do. So I can get away with something smaller and lighter. I will be using on my first version a 300 amp High Output automotive alternator direct coupled to a 16 hp horizontal shaft air cooled engine, probably the old Kohler out back. I am going to use a single wheel dual mount trailer. I expect the total weight to be close to 200 pounds. This system will give me between 3.6K and 4.2K peak yielding 74 volts at 48 amps continuous. When I have all of the bugs out I will purchase a good used 28 volt 400 amp commercial vehicle alternator with a 500cc Honda motorcycle motor I already have lying around. That motor is water cooled so it should run cool. I know the 28 volt 400 amp alts run around $1,800.00 in good condition used. If you shop 500cc or just a little bit bigger Motorcycle motors can me found for under $900.00. 

I plan on removing the regulator and attaching 3-Phase Diode Bridge Rectifier 500A Amp 1600V to get my DC here is a link to one on Ebay. http://www.ebay.com/itm/250984126197?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

I can adjust the voltage by engine rpm. The motorcycle motor is easy to set up for remote control. Using the throttle style with BMX connector between the car and trailer. This system would give me 11,200 watts of power with minimal weight. I have also seen a 10.2K genhead on ebay which was priced reasonable.I am waiting for your real_time power needs. I to would like to be able to drive with my second version when needed. Thanks for sticking with this thread.


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## jacobgoona (Jan 5, 2021)

ken1939 said:


> I'm sure it's not the easiest thing in the world (or "surely someone" would have done it by now)
> 
> 
> Its not so much that, to me there are three reasons.
> ...


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## jacobgoona (Jan 5, 2021)

Hello ! Can some one help me understand how Bridge Rectifiers work. I need to replace one in my power supply for my battery charger for my vehicle. I don't understand how they work completely. I found this article Bridge Rectifier Explanation but I still dont understand if they come in a preassembled module or it is a kit of diodes I have to put together.. Any help at all would be great !


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