# Planning Ford Bronco II/Ranger Conversion w Range Extender



## ElvishWarrior (Apr 10, 2008)

New member here, so I hope folks will forgive me if I inadvertantly kill a few kittens. (I'm new to the forum but not to internet forums.)

I've been reading up on EV conversions for a while and am planning to do one or more in the next year or two. Maybe sooner if things line up. My intended donor vehicle is one I already have.

Vehicle - 1990 Ford Bronco II 4x4 with manual transmission and cruse control. Same platform as Ford Ranger, most mechanical parts are common to the two. In its glory days it got up to 25mpg on the highway.
Currently powered by a 2.9l V6 that's noisy as heck and doesn't pass emissions, so it has to stay off the road until that can be fixed.
There are two efficient cars in the family, but I'm looking for something that wouldn't need petroleum to drive 1.3 miles to work each day, and would provide a solid 4x4 for winter driving. That way I could fuel up every other month instead of once or twice a month, and wouldn't have to start my car cold 4 times a day. Minimizing cold starts to preserve engine life is one of my main reasons for wanting an EV.
Trips in my neck of the woods are either around town (5mi max round trip), to a neighboring town (20mi max round trip) or 40-60 minutes or more to a nearby city. I'd want the first to be pure EV, the second would be nice, and I wouldn't expect the third to work in EV only. Range extended EV perhaps.
I tend to go easy on the gas, getting 40+mpg on a good day from my mid sized car. I typically drive 55-60mph on the interstate, so I wouldn't mind if my EV had a 55mph max speed as long as it could hold speed going uphill. Dropping below 45 on the interstate wouldn't really be my cup of tea.
Overall cost minimization. This would be a first EV using a vehicle I know and own. Advanced EV conversions would be considered later, and would take into account what's on the new car market. No reason to reinvent the wheel at higher cost, higher risk, and with no warranty.

Hopefully that gives a good idea for my basic needs. Here's how I was thinking of doing it, and where I start getting into trouble:
I don't want to sink lots of $$ or space into a battery pack. Looking to use the smallest and least expensive batteries available for a given total voltage.
Part of the reason I don't want to take up too much battery space is that I would like to put a range extending generator under the hood. Specifically a 10hp 7000W diesel generator that would presumably be biodiesel friendly. I would remove the frame and gas tank to save space and hook it up to the truck's fuel system. Even if it means taking it slow and making a few stops to let the generator catch up, I'd like the capability of actually taking an SUV on outings. Just driving it around town seems a little lame, even if it does have zero emissions. Figure that the generator only has to match the average power output of the engine, not the max or even continuous rated power.
I'm firmly decided on DC for cost control and low end torque.
If it is at all possible for the cruise control to work with the EV system that would be excellent.

Here's what I have on the table going into it:
About a month of reading up on EV conversions and a few more of less aggressive interest.
A BSME Degree and a couple years experience, but none of it electrical.
Some basic hobby and science project circuit experience. Highest current application I've dealt with is hooking up a trolling motor to a lawn tractor battery. I have replaced suspension parts and fabricated a minor part of a truck frame.
A small and basic vertical milling machine and a fair bit of experience, but most of it is with woodworking. This may or may not be up to fabricating a motor mount. Purchasing another machine is not out of the question. Neither is purchasing a motor mount to make sure it's done right.
I do have a 240V circuit if needed for charging. The diesel generator I've been eyeing for a range extender also has a 240V outlet.
I'm aware of motor offerings by NetGain, ADC, and D&D as well as the occasional E-bay find. From what I've read I'll be needing a motor rated between 15 and 30hp continuous. But as long as it meets my minimum requirement of 50mph uphill on an interstate I'd like to go with the least expensive and/or most efficient, as long as I wouldn't be damaging it.
I'm not very familiar with controllers. Having some wiring experience, I'm open to the idea of making my own controller using an open source design to save cost or improve efficiency.
Again I'd like to use the least battery possible to save both on weight and cost. IF, and this is a big if, IF the range extender works out I'd really be ok with a 5 mile range, although 20 would be preferred.

I'd greatly appreciate the input of the people on this forum. See any unreasonable expectations? Or any possibilities I may have missed?


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## O'Zeeke (Mar 9, 2008)

Hi Elvish, Welcome to the challenge. check out Nick's 4wd conversion

http://www.driveev.com/jeepev/home.php


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## heynow999 (Mar 2, 2008)

Look on "Mother earth news" there are many examples of what you propose, that were done many years ago!

heres a link to get you going

http://www.motherearthnews.com/Gree...-01/An-Amazing-75-MPG-Hybrid-Electic-Car.aspx


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## ElvishWarrior (Apr 10, 2008)

Wow, those are both excellent and very helpful links. The Jeep conversion gave me a good example of converting a similar vehicle, and the Yugo series hybrid gave a good validation of the series hybrid design I have in mind.

A big question I would have about the Yugo conversion is what size of lawnmower motor and generator were used. Most push mowers I've seen are 5-8hp. If that's the kind of IC engine he's using, then my plan to use a 10hp diesel would about right. As far as I know my vehicle weight is 3300-3500lb, which would of course vary greatly based on how I end up doing a battery pack and range extender. If however he's using a lawn tractor engine which are typically 15-20hp, then my system would be much more limited.

Considering that both vehicles are capable of 65mph cruising, I think I have a little breathing room if the highest speed I need to hold is 55mph.

I'm still up in the air about motor size and battery packs. I was thinking of adding up smaller batteries for a higher voltage battery pack with a moderate amount of energy stored between them all. The goal would be higher motor efficiency and higher torque on command while the energy stored and used on average would be comparable to a lower voltage battery pack. How does this sound? To save on space and cost I was considering using... please don't laugh... lawn tractor batteries. Does the same rule of thumb of battery weight to stored energy apply? Or is that really an unviable option, even if they're added up to a fair voltage like 144-240V?

And then there's the motor. The one that seems the most economical for the power it provides is the D&D ES-31B rated at 18hp continuous and 144Vmax. Would that be a good benchmark? Other's I've been looking at are the NetGain Warp 8 ImPulse or Warp 9 ImPulse as high end options, and a 9" ADC in the middle. Then I occasionally see something on E-bay that looks like a great deal but I don't know where I'd find brushes or other maintenance items. Most tend to be listed as giving high power at lower voltages, leading me to suspect they may be less efficient than typical EV motors.

I'm also pretty open minded about a controller at this point. I had once strongly desired regenerative braking, but then read about how difficult and risky it is using typical DC motors. I can hold off on that until the technology is more standard or I plunk down for an AC conversion at some distant future date.


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## heynow999 (Mar 2, 2008)

I have never built an EV or a hybrid, so I can offer no advice other than what I have read. 

I think the one problem with your idea is that any small generator will probably be real bad for emissions. Modern car have computer controls and catalytic converters so they have pretty good emissions. So you are taking a good idea, an electric car, and powering it from a polluting source. I agree that a diesel and using biodiesel will make this a bit greener. WVO would probably be even better, and cheaper.

I don't want to be a wet blanket, I still think you should go for it. We need to see stories on the evening network news about people who have built cars like this in there garage for $500 in parts. That will get people thinking, "why can't GM build the Volt with a 500 million dollar budget, when ElvishWarrior can with $500"

Good luck


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## ElvishWarrior (Apr 10, 2008)

WVO = ? Never heard that acronym before.

Another point I failed to mention - not only would the generator be more polluting, it would probably be noisier too. To address this I was thinking of hooking it up to the exhaust system already in the truck. Anyone considered this before?

Adding up the costs, this isn't something I'm going to jump into next week. Plenty of time will go into covering all the bases and getting a thorough design with a fair amount of input.

Also, even if I can't get around the pollution, the IC engine would still only come on during weekend trips. Trips around town would be EV only.


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## heynow999 (Mar 2, 2008)

WVO is waste vegetable oil. You go to a local restaurant and make a deal to take there waste oil from them. This is the oil that they deep fry food in. Take it home, run it through a few filters, hook up a second tank to your car or generator, start on diesel then switch to your free oil after it has warmed up.

That is a really brief overview, it is more complicated to execute.

Peter


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## michaeljayclark (Apr 3, 2008)

using a small generator now is not more polluting than the original motor was. most generators are now carb certified.


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## ww321q (Mar 28, 2008)

I posted this under chit-chat the other day

Our discussion on on board generators brought up somethings that I have never liked about measuring pollutants produced by an IC engine . IC engine is nothing more than an air pump . The bigger the pump the more horse power it it is capable of producing and more cubic feet per minute it puts out . We measure pollutants by parts per million . There is no consideration for total volume of pollutants over a given time . Your Honda Civic may not pass smog but I would bet it still produces less pollutants per minute then an SUV with a 6 liter v8........just a thought..... J.W.


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## michaeljayclark (Apr 3, 2008)

the discussion over the onboard generator has been done yes, just the idea that it can be done is what I think he's looking for.


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## O'Zeeke (Mar 9, 2008)

Lawn tractor batteries IMHO would not give you anywhere near the range you would want, in the forum somewhere it was said that pounds of lead are equivalent to pounds of fuel, more is better up to a point. I still have not road tested my Mustang but its about the same weight as your bronco and i am using a warp11 with 18-8V Trojans (144V) for halfway decent performance and range


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## ElvishWarrior (Apr 10, 2008)

From a little bit of surfing on EVAlbum, it looks like the D&D ES-31B run at 144 volts would be just enough.

I spent some time looking at battery specs at a local store. Most of the ones I've been looking at thus far are car batteries. They tend to be rated in cranking amps instead of Amp-hours, but one marine battery had both listed. I think it read 875 cranking amps and 115 Ah. So the ratio would seem to be roughly 1/8 on the conservative side for Ah, perhaps? Or is it not really a direct relation?

Just to humor me on the lawn tractor batteries, here's what I put together using fuzzy math:
12x 12V lawn tractor batteries rated at 275 cold cranking amps. At 1/8 ratio, that would be 34.375 Ah. Multiply that by 144V, and that's 4950Wh. If I don't let my batteries go below 50%, that would be roughly 2.5kWh

Assuming that my average power is 18hp and my average speed is 45mph (pulled out of nowhere), that's 13.5kW. Yes, that would be more than my range extending generator. I'd need to either take long trips really slow or make my average power less than the max sustainable hp of the motor. BTW, most of my range extended trips would be on back roads anyway.

2.5kWh / 13.5kW * 45mph = 8.3 miles.

If those numbers are correct, then that would actually fit within my definition of acceptable, even if a bare minimum. I can work up from there to the best compromise of space, weight, and cost against range. The question is if they are the slightest bit correct.


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## ElvishWarrior (Apr 10, 2008)

I just found the part of the FAQ section that illustrates how to size a battery pack using a sedan as an example. It listed 0.40-0.45 kWh/mile for a 65mph cruise speed for truck/SUV and 0.3 kWh/mile for a medium/large sedan which is probably close to the weight of my BII but more efficient aerodynamically and in the drivetrain. Using my 45mph cruise speed, I'll throw out the estimate of 0.3 kWh/mile average for my BII.

If my calculation of 2.5kWh for the lawn tractor battery pack is right, that ends up at exactly the same 8.3 mile range. So the question that remains is whether my estimation of the Amp-hour ratings of the batteries is correct.


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## 3dplane (Feb 27, 2008)

Elvish!
The average lawn mower battery is around 20 AH. The average small car battery will be around 50-55 AH . Medium to larger car or small truck battery i've seen them up to 73 AH.(in a jaguar seen 90AH but that was a long sucker)Yes like you suspect I would not try to calculate AH from CCA.And keep in mind the fact that they are not deep cycle so they will not stand the abuse as well as deep cycle.(On the other hand I do run car batteries in my golf cart for two years now with no problem but I know the limitations and the load I put on them) Hope that helps out a little. Barna.


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## ElvishWarrior (Apr 10, 2008)

Figured I'd come back to this thread with my latest questions.

My plan now is to use two forklift motors. One is here, the second on the way. One is series, the other is sepex. Both are approx 50lb.

They are listed as 97V and 120V, respectively. The series motor is listed as 29hp at 97V, but I doubt that's continuous. I'm not sure that's max either. The sepex motor is listed as 21hp continuous at 120V, with 70hp peak. I'm taking all those numbers with a grain of salt. Any input would be appreciated.

My plan is to use a 72v battery pack and a separate controller for each motor. I plan to adjust the position of each potentometer in order to line up their performance curves as much as possible. The reason for 72v is to be able to use a regenerative controller by Kelly on the sepex motor. I'm not sure what controller to use on the series motor. There is a prospect for a Curtis 72V 400A at a good price, but still more expensive used than a new Kelly. Input would be appreciated.

I'm thinking that if the 72V setup proves to be inadequate, I could up the voltage to 84 or 96V and still keep the prospect of regen. New controllers would be needed though.

I still wish to use a range extending generator. The problem I'm looking to solve is how to handle the current. I don't know what sort of batteries would take the kind of charging my range extender would give, so I'm looking to size the range extender according to a reasonable charge rate. A custom setup with a 20hp engine running a 10kW generator is a possibility. I'm trying to figure out how a range extending generator could give most of its power straight to the motors while bypassing the charger. I'm assuming an on-board charger would be integral to the range extending setup. Also, I'm worried that between the range extender and the regen, the batteries couldn't handle the energy coming in while going down a long Pennsylvania hill. Which suggests to me that there may be an upper limit to what I can get out of a range extending generator. On the good side, it means it may not be that big. On the bad side, it may not be the indefinite range extender I wanted it to be.

I'm also open to the range extender being outboard, though I would really like it under the hood and hooked up to the exhaust if possible. If outboard, I would plan to stick it in a trailer hitch like a cargo rack.

Based on the lower battery pack voltage with dual motors and range extender, what I think will be most important in a battery pack is the ability to receive and discharge high levels of current back and forth. In other words, I want an ultracapacitor, but will have to settle for the best lead option there is. Starting batteries are still under consideration. EV only range is still not a big deal if the range extending can be worked out. I was considering NiMH, but it doesn't look like it has any advantage there. Someone correct me if I'm wrong.

This will hopefully be a power system that will outlive the Bronco II and find its way into a 4x4 Ranger some day. The BII isn't exactly worth sinking a lot of $$ into, but being worth so little it's not something I would worry about messing up either.


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## Bowser330 (Jun 15, 2008)

When I always think about a range-extending generator (i was thinking propane actually) I always figured you would connect to the battery charger...that way it manages the charge current just as you would normally charge your pack...

maybe you would need some type of contactor switch that you could switch it over to home plug power and not the genset, say you were parked at home or anywhere else with a outlet...

So Im sure if we could calculate what charge a zivan charger can provide to a battery pack we can determine how much range it will be extending? right?


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## ElvishWarrior (Apr 10, 2008)

Hmm, what about some sort of crude high amp charger for the range extender that would only be used when the vehicle was under power?

Or... now this is wild...

A third controller. The range extending generator would be continuously connected to the battery pack via the charger. BUT there would also be a controller between the battery pack and charger. This controler would be controlled by a third potentiometer operated by the same gas pedal as the first two. It would give as much power as the motors are drawing, up to the power level of the generator. Anything above that would draw from the batteries only.

Crazy, yes no?


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## Bowser330 (Jun 15, 2008)

all the research i have done is that optima yellow tops can take high charge amps coming in and they can dish them out too..the only issue is the DOD....I would play it safe and not let your pack go more than 50% DOD...

What generator to use, the 10Kw ones arent cheap, whats cheaper is getting two 5kw ones, maybe one trifuel and one bioD, therefore you have 100% coverage for power, no matter what type of fuel is available you can use it to power your pack...CNG, LPG, Gasoline, Diesel, BioD...

There was a video of Fifth Gear (tv show) and they put a genset in the back of a Smart EV, the video has been removed from youtube...i wonder why..maybe it was too good of an idea.....hmmmm


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## Bowser330 (Jun 15, 2008)

http://www.evalbum.com/682

http://www.evalbum.com/122.html

Same owner two EVs (Hybrids), He is using 5kw gensets for both EVs...

In the over 2 ton truck (4600 lbs) he is getting 80 miles per charge with the 5kw genset running....

If the car was more aerodynamic and weighed less (lithium ion) this 5Kw genset could help the car get closer to double the range....160miles per charge?????


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## ElvishWarrior (Apr 10, 2008)

Using fuzzy math, I'm thinking that if he doubles the range by using the 5kW generator, then his truck requires about 10kW. So with presumably conservative driving, 10kW could extend his range indefinitely.

Going from his project to mine, my truck is about 3300lb with ICE. Fair to assume the ICE is about 300lb, and now we're down to 3000?

Ok, now we add 100lb between two motors. Add another 50 for the dual controllers. If the generator will keep it going indefinitely (if conservatively), then the battery pack would only need to be big enough for the EV only range. How about six 12V 75Ah batteries weighing about 50lb each? 300lb. Now we're up to 450lb. Another 50lb between the 72-12V inverter and the vacuum pump and I'm at 3500lb. Then I have to add the generator, say 300lb for a 10kW setup? So I'm at 3800lb. My vehicle may be a little less aerodynamic, so let's call it even.

Sensible plan? I guess only if there's a way to use that 10kW. Yay, nay on converting to DC and using a third controller as a charger?

One thing making me lean towards using a complete AC generator is an automatic throttle that gives enough gas to support whatever load is applied, and then reduces when it isn't applied. Is there an easy way to do this that would open up more possibilities?


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## Bowser330 (Jun 15, 2008)

you will also be able to lose weight with the exhaust system removed
and fuel tank, fuel system, etc, radiators etc., etc. I also would presume your engine weighs more than 300lbs..so I think you could shed a good 500-600 with all the parts out...


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