# Crazy idea: Using a chevy Volt engine for a range extending trailer?



## joekitch (Sep 13, 2013)

here's my thought process:

The volt is literally designed for this exact use case of being a generator to charge a system that's in active use. If paired with Volt cells in a conversion, would it even be that difficult? 

of course you'd need to replicate the high voltage cabling that exist in the Volt, although no idea if the ICE engine in there goes through the normal plug in charging system, or a totally separate system when it's acting as a generator for the batteries.

also an entire 4 cylinder car engine on a trailer is...not small, but i can't see it weighing in over 1000 lbs for the engine, short heavily mufflered exhaust, a small gas tank, cooling loop with a radiator, the necessary cabling, and a fiberglass cowl on top to keep the weather out. 
Engine testing stands are a thing and they're pretty darn compact...

prices on car part for these engines are between 500 and 1000, not great but not terrible.

Of course, the hard part will be fooling the engine into running when it's totally outside of a normal Volt. I imagine there's a lot of ECU and charge controller hacking i'm glossing over.












thing is, the volt's internal generator is 45kw, so that little thing has as much electric generator capability as this 4000+ pound, $27,000 diesel monstrosity
https://www.coloradostandby.com/winco-mobile-towable-generators-rp55-45kw-diesel-generator
and at 45kw you should be able to maintain charge for most motor setups at cruising highway speeds


*So how crazy is this? has anyone even researched it yet?*


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## rmay635703 (Oct 23, 2008)

Most who have considered the Volt were looking at using the power split 
AS INTENDED
But in a different FWD vehicle, a few looked at locking it into EV only mode others thought of swapping out the 1.4 for something smaller

There are also
Thought experiments 

https://www.diyelectriccar.com/forums/showthread.php/showthread.php?t=107946&amp=1


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## brian_ (Feb 7, 2017)

I don't think GM went to much effort to optimize the engine for the Volt; Toyota's -FXE engines might be a better example. In any case, the engine has no idea what its output is being used for, so you don't need to use the Volt (or Prius, or other similar powertrain) and any engine can work... you just want one which is very efficient when running at the planned power. Having said that, generating while the vehicle is stationary is a normal mode for these vehicles, and some people use a Prius that way.

Running a generator trailer to power an EV creates a series hybrid. There is a good reason that GM went to some trouble to avoid that mode of operation (the Volt normally runs as a power-split hybrid): inefficiency.

The onboard charging system to accept plug-in power is mostly an AC to DC converter; the control of power from the motor-generators to the battery is unrelated to the plug-in part, and regulated by the inverter/controllers for each motor-generator.

Sure, the engine, all accessories (cooling system, exhaust system, etc), generator, inverter/controller, fuel tank, trailer structure, trailer chassis, and body might reasonably be not much more than half a ton.

If concerned about weight, carrying around the Volt's entire transaxle and only using a small fraction of it (one of the motor-generators) doesn't make a lot of sense to me.

I don't know why anyone would want a small fuel tank; the trailer is for long-range use, so it should have a larger tank than a conventional car would have.


The "diesel monstrosity' is heavy because it is intended to run at full power continuously, all day and every day, efficiently.


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## joekitch (Sep 13, 2013)

My thought was that by using the transaxle you maintain all the optimizations (however lazy) gm did to get that thing to push out 45kw, also to reduce cost since the motor+transaxle is only like $750 from a wrecker.... whereas using the engine but putting your own generator on it means you need to find a pretty darn good generator and make an adapter plate etc. The two things you get at that point (over using the stock transaxle) are more control over the generator, and saving maybe a hundred pounds or so since you don't have the extra motor dead weight compared to a smaller motor + adapters. But for the lower overall cost and the lower need for bespoke controllers, I think using the stock transaxel is worth it.
Of course, it shifts your effort into making the transaxel firmware do what you want in terms of pushing kilowatts when you want it.

The small fuel tank is for safety (less volume of boom boom), but I guess having a stronger tank isn't too difficult or heavy. Keep in mind these engines get a solid 40 mpg in generator mode, so a 5 gallon tiny tank still gets you 200 miles of range assuming your highway cruising isn't drawing more than 45kw (I'll admit I'm not actually sure what the numbers are on power draw at 60mph).... Although on that same token you could go freaking 800 miles on a single 20 gallon tank! Solid 13 hours of straight driving without dipping into batteries, holy cow.

A totally separate charging circuit will add some complexity of a different charger on top of the plug in charger, but I can't imagine it's too bulky? 

One thing I have no idea about is how would the wiring from the trailer to the batteries work? Would it just be some big ass cables with a really beefy super locked connector going from the generator inverter into the generator charger that'll live in the car? That's definitely need some bespoke stuff, including safety systems to pop connections and fuses in the case of a runaway trailer!

Also what is even involved in making a volt engine "just run" on command and the generator to just make power. 
How much of the engine do you need to fool? How much of the original volt do you need? 
Could you use a totally separate aftermarket ECU to run the engine and just not do anything to the generator, just get the high voltage cables and trust it'll make the power you want?

Please note I'm a complete idiot and I'm throwing out ideas to see what's feasible or not, hoping some folks come along to say "well actually" and set me straight.


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## joekitch (Sep 13, 2013)

Also, if one wants extra safety for an outboard fuel tank. Racing safety fuel cels~~
https://fuelsafe.com/motorsports/racing-fuel-cells/


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## brian_ (Feb 7, 2017)

joekitch said:


> My thought was that by using the transaxle you maintain all the optimizations (however lazy) gm did to get that thing to push out 45kw..


No, the transaxle doesn't change how the engine operates; it would run exactly the same way with a just a generator, given suitable control logic. 45 kW is only 60 hp... that's trival for the engine.



joekitch said:


> ... also to reduce cost since the motor+transaxle is only like $750 from a wrecker.... whereas using the engine but putting your own generator on it means you need to find a pretty darn good generator and make an adapter plate etc.


Yes, but you carry around a lot of hardware for that cost saving and convenience.



joekitch said:


> The small fuel tank is for safety (less volume of boom boom), but I guess having a stronger tank isn't too difficult or heavy. Keep in mind these engines get a solid 40 mpg in generator mode, so a 5 gallon tiny tank still gets you 200 miles of range assuming...


To me, 200 miles is unworkably short for highway travel, making any significant trip into a continual fuel stop planning exercise. You don't need to use all of the available range if you have more, but it lets you stop for fuel when you want, instead of when you need to.



joekitch said:


> One thing I have no idea about is how would the wiring from the trailer to the batteries work? Would it just be some big ass cables with a really beefy super locked connector going from the generator inverter into the generator charger that'll live in the car? That's definitely need some bespoke stuff, including safety systems to pop connections and fuses in the case of a runaway trailer!


Right... and I think you want a connection which will safely pull apart rather than get destroyed if the cable is pulled. Even the connection from a Level 2 charging station to an EV (which is fundamentally just a 240 V AC plug-in) has safety interlocking, and that's in a stationary application.


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## Telco (Jun 28, 2008)

So the Volt has a 45kW generator set on board? Wild! I spent weeks trying to find a 50kW genset for my truck, while planning a conversion. Only, I don't want to do a trailer, I wanted to install it permanently and use it as a series hybrid.

I figured on 50kW based on using a Tesla X drive unit. To drive my truck at the cruise speed I want, it will take about 67HP which is right at 50kW. This is really overkill, because I overestimated the vehicle weight. And, if it came to it, I could just cruise the speed limit. 

Unfortunately, I also came to the conclusion that I would only be seeing about 18MPG max going this way, so I'm not going to do it. I have an alternative that will get me 40+mpg in the same truck, which currently gets 15mpg. The 15 year old V6 and 4 speed is coming out, and a modern V8 and 8 speed is going in. I'll look into the Volt drivetrain just the same, because if I can get what I want with electricity I'd rather go that way and what I want is 10 second quarter miles and 40+mpg cruising.

This is the link I used to figure out required HP. The field information needed like frontal area and cD can be found online. Frontal area, find you vehicle's height and width in inches online, multiply one by the other, then divide the answer by 144 to convert to square feet. Whatever it comes up with, multiply by 746 to get the wattage required to maintain speed. 

http://www.wallaceracing.com/Calculate HP For Speed.php

This site does similar, but claims I need 10hp less to maintain speed.

http://www.tritrack.net/horsePower.html

Hope some of this helps.


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## joekitch (Sep 13, 2013)

the 45kw number i'm pulling right from that infographic on the volt engine










so it's accuracy is....hmmm..

also keep in mind if you aren't covering 100% of your cruising energy with the generator it's not that bad. The idea is to extend your range, not totally replace it with gas, which would be a pretty lofty goal and most of the time you'd be spinning a generator for nothing. If instead you get triple your standard range because you're consuming battery power at a third the rate, that takes your 100 mile range project to 300 miles instead!

but, have no clever electrical engineers tried anything like this yet? Generator trailer ideas keep popping up and going nowhere, it's pretty disheartening


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## brian_ (Feb 7, 2017)

joekitch said:


> the 45kw number i'm pulling right from that infographic on the volt engine
> 
> ...
> 
> so it's accuracy is....hmmm..


Marketing people frequently mess up technical content, but that image is from GM... it's probably trustworthy. 45 kW is entirely reasonable for the output side motor-generator in a power-split transmission for an engine of this size. It's probably capable of more than that; the total output of both motors is listed as 129 HP (96 kW), and the 45 kW value is for regenerative braking output, which may be limited by acceptable battery charging rate (rather than the motor-generator).


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## brian_ (Feb 7, 2017)

joekitch said:


> ... also keep in mind if you aren't covering 100% of your cruising energy with the generator it's not that bad. The idea is to extend your range, not totally replace it with gas, which would be a pretty lofty goal and most of the time you'd be spinning a generator for nothing. If instead you get triple your standard range because you're consuming battery power at a third the rate, that takes your 100 mile range project to 300 miles instead!


The generator only needs to cover the average power demand for range to be limited only by fuel. If the generator's continuous output matches the average, it will never idle; the generator will only idle most of the time if it is sized for peak power demand, rather than average.

The REX version of the BMW i3 is a series hybrid (as any EV with an added charging trailer would be); it has a little 25 kW engine (a 0.647 L two-cylinder from a scooter). If not deliberately hobbled by software limits set to game California regulations, it can keep up with cruising demand for the car as long as the fuel lasts.


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## brian_ (Feb 7, 2017)

joekitch said:


> ... but, have no clever electrical engineers tried anything like this yet? Generator trailer ideas keep popping up and going nowhere, it's pretty disheartening


I think most trained and experienced engineers would realize how rare suitable applications would be, given the efficiency and implementation issues, so they don't pursue the idea. And most of the details of a generator trailer are mechanically engineering issues, not electrical; the charging control is the only significant electrical technical challenge.

The BMW i3 is one of the very rare series hybrids in production; it is essentially the same as an EV plus a charging trailer, but is much more convenient to drive (except for the tiny fuel tank), and its poor fuel economy demonstrates why this sort of system is problematic. A larger engine would likely be more efficient, but the car-plus-trailer implementation would be an efficiency disadvantage due to rolling and aero drag.


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## joekitch (Sep 13, 2013)

brian_ said:


> which may be limited by acceptable battery charging rate (rather than the motor-generator).


this is what i'm worried about with a chevy volt system. Can it actually push 45kw from the generator into the battery continuously? I think the regular volt can give enough juice to maintain highway driving without dipping into the battery....but doesn't the volt just have the gas engine "directly" (without the battery as a middle ground) power the wheel motor when at higher speeds? 
I'm really hoping it's the former.


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## rmay635703 (Oct 23, 2008)

The Volts system power is 108kw

On gas only it can dip into the battery buffer to make up the difference


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## brian_ (Feb 7, 2017)

joekitch said:


> this is what i'm worried about with a chevy volt system. Can it actually push 45kw from the generator into the battery continuously?


I don't see why not. It's not much compared to available engine power, and not surprising for the motor-generator. The inverter-controller will be sized to suit the application.



joekitch said:


> I think the regular volt can give enough juice to maintain highway driving without dipping into the battery....but doesn't the volt just have the gas engine "directly" (without the battery as a middle ground) power the wheel motor when at higher speeds?
> I'm really hoping it's the former.


A Volt can accelerate hard up to and beyond typical highway speed without needing energy from the battery (although the battery needs to be functional - pull it out entirely and the car is likely dead).

The Volt transaxle has multiple operating modes, and the list of modes depends on the generation of Volt. Modes with a mechanical transmission path (the "power-split" feature of the transaxle, also used by the Prius and other Toyotas, Ford hybrids, and non-GM two-mode hybrids from BMW and others) are used for efficiency, not due to limitations of the motor-generator sizes.

The battery is always in the power flow, but only the net difference between what is generated and what is used goes into or out of the battery. This is true of any system which "floats" the battery, which is how all hybrids work.


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## CanadaLT28 (Oct 15, 2011)

Before I decided on 2 Leaf motors, I was thinking of having one in the front acting as a generator being driven by a TDI. The torque curve for the TDI is ideally suited to driving a Leaf and I could generate 60kw with no problems. I had been thinking of the idea of the trailer with this system as well for long hauls.


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## brian_ (Feb 7, 2017)

CanadaLT28 said:


> Before I decided on 2 Leaf motors, I was thinking of having one in the front acting as a generator being driven by a TDI. The torque curve for the TDI is ideally suited to driving a Leaf and I could generate 60kw with no problems. I had been thinking of the idea of the trailer with this system as well for long hauls.


Given the substantial size of this truck, you could even build the generator set on a skid to be carried on the truck's deck... not that it would avoid the inherent inefficiency of a series hybrid, but it would avoid towing a trailer (and the resulting aero drag).


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## CanadaLT28 (Oct 15, 2011)

brian_ said:


> Given the substantial size of this truck, you could even build the generator set on a skid to be carried on the truck's deck... not that it would avoid the inherent inefficiency of a series hybrid, but it would avoid towing a trailer (and the resulting aero drag).



That would be nice but the bed will be taken up, most of the time during long distance travel, by a pop up hard top camper. I noticed that my current fuel economy with 1 tonne of solar panels on the back doesn't change much but towing a 14' Bigfoot camper is really bad so every effort will be taken to make the camper as aerodynamic as possible, hence the pop up.


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## brian_ (Feb 7, 2017)

CanadaLT28 said:


> brian_ said:
> 
> 
> > Given the substantial size of this truck, you could even build the generator set on a skid to be carried on the truck's deck...
> ...


That makes sense. Fortunately, a generator trailer would be narrower (or much narrower, if by 14' you mean a later 17' Bigfoot with a 14' long body) than the Bigfoot, so it would not be the same aerodynamic problem. If the generator trailer would typically be used with the camper, but not always, it could be designed with a load deck on top (matched to the truck deck height?) so that when carrying the camper the trailer could carry cargo which would be in the aerodynamic "shadow" of the truck and camper.


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## Telco (Jun 28, 2008)

brian_ said:


> Given the substantial size of this truck, you could even build the generator set on a skid to be carried on the truck's deck... not that it would avoid the inherent inefficiency of a series hybrid, but it would avoid towing a trailer (and the resulting aero drag).



One thing to consider, the driven motor (generator) will not generate enough to drive the drive motor at 100 percent. You'd be looking at probably 80 percent by the time line losses and whatnot are taken into account. In the past I considered doing something similar only using Warp engines, and was looking at using a Warp 11 for the drive motor and a Warp 13 for the driven motor. I wanted the ability to run the drive motor at 100 percent, while still having enough juice to run the rest of the car. This may not actually be a concern for you, but it's something you should be aware of nonetheless.



I really wish the infrastructure and battery tech were at a point where you can stop at any corner gas station and fully recharge the battery in 5 minutes, going 100 percent would be a no brainer. Due to family and work I need to be able to jump in and drive 12 hours nonstop at the drop of a hat, so I'm probably going to be driving a gasser all my life because of it.


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## CanadaLT28 (Oct 15, 2011)

brian_ said:


> That makes sense. Fortunately, a generator trailer would be narrower (or much narrower, if by 14' you mean a later 17' Bigfoot with a 14' long body) than the Bigfoot, so it would not be the same aerodynamic problem. If the generator trailer would typically be used with the camper, but not always, it could be designed with a load deck on top (matched to the truck deck height?) so that when carrying the camper the trailer could carry cargo which would be in the aerodynamic "shadow" of the truck and camper.


Yes, you are right. It is the 17ft Bigfoot with a 14ft body. I suspect the power trailer would be somewhat like the size of a bigger motorcycle trailer and could easily be designed to fit into the slipstream of the truck, even act as a drag reducer similar t those on the back of a semi trailer.


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## CanadaLT28 (Oct 15, 2011)

Telco said:


> One thing to consider, the driven motor (generator) will not generate enough to drive the drive motor at 100 percent. You'd be looking at probably 80 percent by the time line losses and whatnot are taken into account. In the past I considered doing something similar only using Warp engines, and was looking at using a Warp 11 for the drive motor and a Warp 13 for the driven motor. I wanted the ability to run the drive motor at 100 percent, while still having enough juice to run the rest of the car. This may not actually be a concern for you, but it's something you should be aware of nonetheless.
> 
> .



In my travels with our Pacifica Hybrid, steady state (ish) 100kmh is around 25-35kw. Now I know that the aerodynamics of an old car, and especially my VW brick, is much worse than a new car but the combination of the TDI and a Leaf motor producing around 60kw at 1800rpm results in much less fuel consumption than a normal Jetta would. And, if I can get 60kw production whilst consuming perhaps 40kw, the motor would only have to be on for a fraction of the time. If the car is other than my brick, the numbers should be better.


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## MattsAwesomeStuff (Aug 10, 2017)

> In my travels with our Pacifica Hybrid, steady state (ish) 100kmh is around 25-35kw.


40hp to maintain highway speed on a flat?

That's awful.

500Wh/mile. Hrm. Okay, for a bigger vehicle I guess that's not so bad.


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## rmay635703 (Oct 23, 2008)

Go smaller

https://m.youtube.com/watch?v=M_3-3zIdNG0&feature=youtu.be


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## joekitch (Sep 13, 2013)

rmay635703 said:


> Go smaller
> 
> https://m.youtube.com/watch?v=M_3-3zIdNG0&feature=youtu.be


heh, body swap a prius is a really interesting move, actually. 

however the generator trailer is a solution to several problems that won't be solved any time soon
>getting decent (200+ mile) range on a classic conversion means an absolute boatload of batteries, there might not be room for them AND 
>even tesla supercharging is half an hour for 0 to 80%, and good luck making supercharging work on a DIY. Even other fast charge systems like CSS are really hard to get on a diy 
>the charging network is sparse, the fast charging network even moreso.

hence why i'm so interested in this. Don't need to add some many batteries, Keep your conversion's weight very low, don't need to ruin the car to find enough room to add batteries as well. If you're ever worried about range for a trip, hook up the trailer and just go


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## joekitch (Sep 13, 2013)

bumping this thread back up

the chevy volt motor's rated electrical output is 55kw
so, in theory, if i can keep my power consumption under 550wh per mile at highway speed of 70mph, it should charge my batteries.

although even if it doesn't charge them, if it just slows the discharge down, that's still a huge boon in terms of range.

now, will a P90 rear drive unit powered 1971 corvette towing a 1000lb trailer pull more than 550wh/mi? i'm not sure. 

considering most model Xs seem to average around 350-400 wh/mi, 550 seems like a reasonable ceiling.

*but the real question is wiring*, would the engine need to go through the main change controller? or* would it be wired in parallel with the entire battery pack *or something?
what problems could result from a moving car being charged? If it just causes battery heat that's easy to fix with more aggressive cooling


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## brian_ (Feb 7, 2017)

joekitch said:


> the chevy volt motor's rated electrical output is 55kw


I would say that's the hybrid transaxle's rated electrical output, not an engine output.



joekitch said:


> so, in theory, if i can keep my power consumption under 550wh per mile at highway speed of 70mph, it should charge my batteries.


550 Wh/mile at 70 miles/hour would be 38.5 kW... so yes, a 55 kW supply would keep up. Or, 55 kW divided by 70 miles/h is 786 Wh/mile, so with a 55 kW generator you could use up to 786 Wh/mile (which is very high).



joekitch said:


> although even if it doesn't charge them, if it just slows the discharge down, that's still a huge boon in terms of range.


Yes, even a lower output would extend range. The difference between power consumption and power supply is the net power which must be supplied by the battery.



joekitch said:


> now, will a P90 rear drive unit powered 1971 corvette towing a 1000lb trailer pull more than 550wh/mi? i'm not sure.
> 
> considering most model Xs seem to average around 350-400 wh/mi, 550 seems like a reasonable ceiling.


Given that the C3 will probably have a worse aero drag coefficient than a Model X but less frontal area, and the trailer adds drag, that seems reasonable to me... but we're only making educated guesses.



joekitch said:


> *but the real question is wiring*, would the engine need to go through the main change controller? or* would it be wired in parallel with the entire battery pack *or something?
> what problems could result from a moving car being charged? If it just causes battery heat that's easy to fix with more aggressive cooling


The generator's output can't go through the AC-to-DC section of the charger, but you still need control, as discussed earlier:


brian_ said:


> The onboard charging system to accept plug-in power is mostly an AC to DC converter; the control of power from the motor-generators to the battery is unrelated to the plug-in part, and regulated by the inverter/controllers for each motor-generator.


You would need an equivalent to the inverter/controllers used in the Volt, acting as a rectifier and charge controller, and something still needs to tell that controller what voltage to output, and something needs to tell the engine controller (ECU) how much power to produce. Yes, the power output of that charge controller would be connected to the battery in parallel with the car's drive motor controller.


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## joekitch (Sep 13, 2013)

brian_ said:


> You would need an equivalent to the inverter/controllers used in the Volt, acting as a rectifier and charge controller, and something still needs to tell that controller what voltage to output, and something needs to tell the engine controller (ECU) how much power to produce. Yes, the power output of that charge controller would be connected to the battery in parallel with the car's drive motor controller.


ah, so it's not like generator -> battery - > motor
it'd be more like generator + battery -> motor
both would be giving the voltage needed, the motor would just be drawing from both.

although that sounds like it'd be a nightmare, like the generator needs to give power in lock step with the battery or something complex like that. I was hoping it'd be more like you just dump power into the batteries in a parallel configuration, but the motor controller and batteries are still "in charge" and handle all the vroom vroom on their own, to the point where you could disconnect the generator at speed and the system wouldn't even notice


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## joekitch (Sep 13, 2013)

actually, if a normal charge controller won't be able to handle the kw i need to run the car at highway speeds (350 watt hours at least)...
why not just use chademo?

the whole exercise is about dumping DC amps into the battery, and chademo can do that just fine and pretty easily too


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## brian_ (Feb 7, 2017)

joekitch said:


> actually, if a normal charge controller won't be able to handle the kw i need to run the car at highway speeds (350 watt hours at least)...
> why not just use chademo?
> 
> the whole exercise is about dumping DC amps into the battery, and chademo can do that just fine and pretty easily too


I assume that you meant 350 Wh/mile, so the average power is that multiplied by the average speed, such as 21 kW at 60 MPH.

Yes, the connection between the car and a generator trailer can be treated like the connection between the car and charging station. Since there's no point in going through an AC stage at all, it's like DC charging, and CHAdeMO and CCS are the two standards for that. In addition to the handshaking/interlocking features of each of these protocols, the car needs to tell the generator trailer what current to supply (and presumably what maximum voltage to reach), and something on the generator trailer needs to tell the inverter/controllers to produce that current.


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## brian_ (Feb 7, 2017)

Since this thread has been revived, I'll note that there are other possible donor vehicles. In addition to the obvious Toyota hybrids and the already discussed pure series BMW i3 REX, there are two which actually run in a series hybrid mode at least at low road speeds: the Mitsubishi Outlander PHEV and the Honda Accord with Intelligent Multi-Mode Drive (i-MMD) two-motor hybrid powertrain.

In each of these vehicles there is a generator which is always coupled to the engine, a motor which is always coupled to the wheels, and a clutch (plus fixed-ratio gearing) between them. That means that the engine and transaxle can be converted to a pure generator set by removing the motor and disabling or removing the gearing, with the result being power limited to a level which would be adequate for this purpose (60 kW peak or 30 kW continuous in the Outlander, for instance). An advantage to these vehicles is that pure series operation is a mode which is part of their design (Honda calls it "Hybrid Drive", in contrast to the parallel mode "Engine Drive"), and requires (for the charging trailer application) control of only one generator and no clutches; the Volt can be more complex.

As with the Volt, the 2.0 L engine in each vehicle is much more powerful than required to drive just the generator. With some control changes it should be possible in both cases to engage the clutch and use both the usual generator and the drive motor as generators, for higher electrical power output, although it's not needed for the generator trailer application. In the Outlander system the extra motor can be easily removed (perhaps to sell it or use it for another vehicle); in the Accord I think both motor/generators are integrated into one case and not readily separated.


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## electro wrks (Mar 5, 2012)

Mr. Sharkey, I think, still has this totally mechanical ICE pusher trailer operating after many years: Mr.Sharkey's Pusher Trailer

It does have some advantages in efficiency and ease of construction. The power from the ICE is applied more directly to the road as compared to the more circuitous route of ICE to generator to battery/motor to road path. I know the Volt has the potential of this more efficient route, but its drive train and control seems to be a lot more complicated.

Let's hope with better batteries and an expanding charging infrastructure this whole discussion will become moot in the very near future.


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## joekitch (Sep 13, 2013)

brian_ said:


> As with the Volt, the 2.0 L engine in each vehicle is much more powerful than required to drive just the generator. With some control changes it should be possible in both cases to engage the clutch and use both the usual generator and the drive motor as generators, for higher electrical power output, although it's not needed for the generator trailer application. In the Outlander system the extra motor can be easily removed (perhaps to sell it or use it for another vehicle); in the Accord I think both motor/generators are integrated into one case and not readily separated.


that would be the idea, either mechanically (by welding or something) or electronically, engage the clutch which turns the motor on the volt engine into a generator, and take the combined 48kw as continuous chademo charging.
however yeah i'm not sure how to make the motor change its amp output, as needed for chademo to work right, is it just revs?

as for charging overall i'd just have it only kick on if the battery is under 70%, then keep running till it's over 80%, then wait till it hits 70 again, it'd be easier than setting it up to give more amps based on my current watt hours per mile consumption or something. Also, under 80% i'm nowhere near the possible issues of throwing balance way off by topping the batter using a charge method that doesn't top balance like level 2 does.

but man those i3 REX generators keep looking better and better, they're so dang cheap and tiny!



electro wrks said:


> Mr. Sharkey, I think, still has this totally mechanical ICE pusher trailer operating after many years: Mr.Sharkey's Pusher Trailer


to be honest pusher trailers scare the hell out of me 
when you drive trailers often, one of the scariest scenarios is when your trailer isn't braked and starts pushing your car around 
it's like trying to balance a pencil on your finger by the tip, the system is inherently unstable
maybe it works much better on much lower power cars?


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## Isaac97 (Jun 3, 2019)

You don't need CHAdeMO. A connector of that sort might be a good idea (though a CCS plug is cheaper) but you just need, as you said, a way to control amps and volts.
The generator inverter is inherently able to output battery voltages at any speed, just like your motor inverter is able to make the motor turn at any speed from battery voltage. It's basically regenerative braking.

Are you planning to use the original Volt inverter and controller, probably over CAN? That would be the easiest from the point of view of limiting HV work. But very difficult to reverse engineer. I would guess that the car requests a specific amount of power and sets a voltage limit -- just like a regular charger. So the generator might output 100A until the battery hits 390V.

If you want more precise and fully customizable control, you could put an OpenInverter board into the Volt inverter. Then you just lock it into regen mode (fairly easy) and set voltage and current limits -- then use another microcontroller to turn on and shut off the ICE when necessary.





 - you've probably seen this, if not watch it. There are hydraulic clutches which you could just weld together to lock both motors to the ICE. Then you could get 110Kw out of the system if you wanted.
Personally, I'd stick with a single motor; the original electronics probably will not like two of them, and the OpenInverter system only controls 1 at a time unless they're synchronized exactly (or you just use 2 control boards).

I've actually got a Volt inverter in my car with an OpenInverter controller along with a Siemens motor - something like 65Kw continuous with good cooling and I've pushed 140kw for brief periods. It's all coming out soon because it's not behaving well with the transmission. Maybe PM me if you're interested in it? I could definitely help you with setup and configuration.

-Isaac


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## joekitch (Sep 13, 2013)

the question is if the charging system needs to be "smart" in any way. Like if i need it to deliver amps in a PID temp style of slowly ramping down as it reaches its target

if it can be dumb as a rock, literally just the engine turns on and delivers a fixed amperage until the car bms say its at 80% then switch off, that makes things way easier

i'm using 80% since it's full-ish without getting anywhere near the top end of the battery, but should i be aiming for 70% instead?


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## Isaac97 (Jun 3, 2019)

Dumb as a rock will work great. You only need to ramp current down if you want to charge to 100%.
Any charge level would work; 80% would let you run the engine less often (but for longer), whether that matters or not. 

Or you could try charge-sustaining mode, where once the battery discharges to 20% the generator turns on and keeps charge about that level.

Theoretically, higher battery voltage gives slightly better efficiency, so you could set it up to turn on at 50% and turn off at 80%.


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## remy_martian (Feb 4, 2019)

It's that "just turn the engine on and deliver fixed amperage" that's tricky AF - something I wouldn't tackle as an electrical engineer. You'd have to PID control the engine throttle with a custom governor that delivers the current the car asks for. Then there's safety - being on a trailer, a disconnect (that includes a bad connector) means engine overrun and stuff-toasting voltages.

For the weight, I'd just do an aux battery pack on a trailer. I know a guy who's selling some Tesla Modules in the classifieds... 🤓


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## joekitch (Sep 13, 2013)

that was the plan, turn on at 50%, turn off at 80%, and it'll run for however long it needs to in order to meet those numbers.

i would be surprised if amps were dictated by anything other than engine rpm, and getting the engine to just start and run at 2000 rpm forever should be relatively easy compared to like, making a full custom map for all revs? If i'm lucky i can trick the ecu into just starting and doing its thing, if i'm unlucky i'll need to use a megasquirt ECU to do that. same with the volt inverter, lucky i can use the stock one, unlucky i use an openinverter control board

trailer safety is a relatively solved problem, with emergency spring loaded brakes connected to one of those runaway cable things they use in europe, tie that into also shutting off the engine and disconnecting the high voltage connection to the car and in any runaway scenario the trailer should just stop altogether.










for added safety i'd use a racing fuel cell instead of a gas tank, since they're much tougher and have internal baffles etc. I don't need it to carry much gas at all, 10 gallons at most really and maybe only 5. 

the problem with a battery trailer is it has the same problem as the car itself: not enough fast chargers around.


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## remy_martian (Feb 4, 2019)

It's not as simple as running the engine at 2000 rpm - that will give you constant voltage, not constant current, from a generator. The slightest change in pack impedance, like cells getting bypassed by the BMS during charging, will vary the current into the pack -- your engine has to respond to these load changes.

And the disconnect I am taking about is at the _electrical_ connector. In operation, not when it comes off the hitchball. That also is a nontrivial problem.


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## Isaac97 (Jun 3, 2019)

A 3-phase motor with an intelligent inverter can generate any voltage level at any RPM within reason by the use of field weakening. This is not a DC motor we're talking about, it's got an intelligent controller. 
So yes, you can get constant power out, and then decrease that power as necessary in case of voltage rises. Electrical power can be cut off if voltage rises too high (indicating the connector coming loose). 

Holding the engine at an RPM should be relatively easy, it's practically cruise control minus 3000lbs.

Cells do not get bypassed by the BMS; the BMS is able to drain small amounts of current to keep cells in balance, but that has practically zero effect on the overall pack voltage - 100mA quoted here.

Disconnect is an issue only if current is flowing, since the motor power can be shut off instantly by the inverter. (And I mean instantly - within milliseconds of a problem being detected).
A J1772 connector uses a latch with a button to shut off before being disconnected, but also first to break/last to make signal and ground pins, so that if it's unplugged the power can be shut off before the power pins disconnect. So something similar would work well. 
You'd also want contactors on both sides, a la CHAdeMO, to isolate high voltage when the plug is disconnected.

Overall, this is a very feasible project as long as you can get the engine running and the transmission clutches engaged (maybe weld things up internally?).

-Isaac


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## brian_ (Feb 7, 2017)

joekitch said:


> trailer safety is a relatively solved problem, with emergency spring loaded brakes connected to one of those runaway cable things they use in europe, tie that into also shutting off the engine and disconnecting the high voltage connection to the car and in any runaway scenario the trailer should just stop altogether.
> 
> View attachment 120207


Those rod-linked overrun braking systems are ubiquitous in small trailers in Europe, but very rarely used here - it's hard to find a coupler for them with anything other than a 50 mm ball, or to find a 50 mm ball for a North American hitch. The common alternative here is a hydraulic surge brake setup. Either of these and an electric braking system all have a breakaway cable; using that cable to trigger an engine shutdown and high voltage disconnect does seem like a good idea to me.


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## brian_ (Feb 7, 2017)

I really don't think you want to directly control engine speed - there's an engine management computer for that. Requesting a constant power output, or just letting the appropriate Volt operating mode do its job, seems like a better idea. The Volt engine should run at the engine speed which is most efficient for the power to be generated. The biggest problem is that you have a choice of running in a mode which looks like a stationary car (no axle rotation, so the output side motor-generator MGB can't be used), or going to a lot of work to fool the system into thinking that it is coasting (moving but with no load on the axle outputs) and needs to top up the battery. According to one description in a second-gen Volt the forced charging at a standstill might be "mountain mode", but certainly a reading of the owner's manuals for both generations would be advisable.

This would be easier to understand with a series hybrid such as the Outlander PHEV or Accord Hybrid, which at low road speed has no mechanical connection between the engine and the axles, although of course in that case again you wouldn't be using the drive motor as a generator. Even a Prius is mechanically simpler than a Volt and knows how to charge while stationary (again, not using MG2) - that's "Battery charging" mode in the Wikipedia description.


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## brian_ (Feb 7, 2017)

remy_martian said:


> The slightest change in pack impedance, like cells getting bypassed by the BMS during charging, will vary the current into the pack -- your engine has to respond to these load changes.





Isaac97 said:


> Cells do not get bypassed by the BMS; the BMS is able to drain small amounts of current to keep cells in balance, but that has practically zero effect on the overall pack voltage - 100mA quoted here.


It's true that cells don't get disconnected from the series path through all cells under any circumstance, by the BMS for balancing or otherwise, so in that sense a cell is never completely bypassed. On the other hand, when the BMS drains current to balance, it is bypassing (or "shunting" - connecting another path in parallel) the cell group being adjusted with a relatively high resistance (resulting in a relatively low current); if that is done while charging then the overall pack resistance is slightly reduced.


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## joekitch (Sep 13, 2013)

brian_ said:


> I really don't think you want to directly control engine speed - there's an engine management computer for that. Requesting a constant power output, or just letting the appropriate Volt operating mode do its job, seems like a better idea.


What you're saying is let the volt engine and inverter do what they need to as defined by chevy..... but in my experience the more modern a car gets, the more difficult it is to make the engine run "headless", as in, just an ecu in empty space.

there's so much cross talk and interdependence that it can get infeasible fast.

if i'm lucky it'll just be a matter of porting over the key system, and with that in place it'll happily pretend its a regular car and just do its thing
if i'm unlucky i'll have to do something more drastic like spoofing a deluge of signals and data for the ecu and inverter controller to be "happy", which will involve a ton of reverse engineering and can sniffing

if someone's already done all this work though, and i'm just using someone else's can message package while changing a few can messages to put it into mountain mode as soon as it starts, that's great, but i don't think anyone has?


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## brian_ (Feb 7, 2017)

joekitch said:


> What you're saying is let the volt engine and inverter do what they need to as defined by chevy..... but in my experience the more modern a car gets, the more difficult it is to make the engine run "headless", as in, just an ecu in empty space.
> 
> there's so much cross talk and interdependence that it can get infeasible fast.


True, but if anything is worse than running the system out of the context of the car, it's running only part of the system in any context. The logical alternative to the Volt's engine and hybrid system controls is to throw them away entirely and in their place put on a complete aftermarket ECU and an aftermarket or DIY controller section in the inverter of motor-generator A. The other motor-generator and most the gearing will all just be ballast, or you could pull everything unnecessary out and put in whatever spacers and seals are required to keep the remaining bits alive. The engine control would be set up for full load (wide open throttle); the inverter control would be set to adjust load (charging current) to maintain a set speed (corresponding to the most efficient engine speed for the target operation).

It might be possible to keep the engine's ECU and command it from a custom controller which would also command the (presumably aftermarket or DIY) controller in the inverter.

The nice thing about the idle charging mode is that not much should be needed to be spoofed: no axle speeds, for instance.


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## joekitch (Sep 13, 2013)

....hence megasquirt, which is an extremely popular open source ECU which works with just about anything that makes booms to turn wheels, and the open inverter board to handle the inverter side, and potentially some cross-talk between them so the inverter board can ask for more or less revs if it needs them.

of course all this is contingent on me getting the hardware to experiment with. I can find the volt engines all day long for $500 to $1000 but the inverter assembly seems to be referred to as the transaxle in this case, and floats around ebay for a little under $1000, this one for instance appears to have everything, including the inverter control under the black plastic
2013 13 CHEVROLET VOLT AUTOMATIC TRANSMISSION ASSEMBLY 24256617 OEM | eBay


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## remy_martian (Feb 4, 2019)

How do you control the inverter? CAN?


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## joekitch (Sep 13, 2013)

i believe both megasquirt and the openinverter board can chat over can messages
if not i'll need to do something weird with an in-between board


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## Isaac97 (Jun 3, 2019)

That picture is just the generator/transmission. Inverter is all metal, that's where those 6 wires/2 connectors go.
Here's a cheap one Engine ECM Hybrid-electric Drive Motor Control Fits 11-15 VOLT 364633 | eBay


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## joekitch (Sep 13, 2013)

Ok so shopping list wise it'll be engine, transmission/generator assembly, the inverter box, a megasquirt board, and an open inverter board, and that's just to get it on a stand for testing

if this whole setup works well, it could really open the door for super daily driveable and usable ev conversions which don't need to pack on a ton of batteries 

i really need to find someone who worked on the Volt team to pepper them with specific questions....


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## brian_ (Feb 7, 2017)

Since we're talking about controlling the engine, it might be interesting to note how the engine should run... that is, at what speed, load, and resulting power.

The following graph is found in various online discussions.
_GM-Volt forum_: Understanding the Volt's extended range mode (graph)
_SpeakEV forum_: Are PHEV manufacturers being lazy about charge-sustain efficiencies? (graph)
It presumably originated with GM, but I have not found and authoritative source and am only assuming (based on it being entirely plausible technically) that it is valid. It was probably in presentation material is not currently published to the web by GM.
View attachment 120222


The label says "Family O 1.4-l gen. 3" because this engine is part of GM's "O" family, has a displacement of 1.4 L, and is the third generation of this design; the version used in the Volt (apparently for both generations) is specifically the A14XFL, identified by order code "LUU" (like the code for the V8 engines commonly swapped into everything now is "LS3"); it differs from other A14Xxx (same family, generation, and displacement) variants in having a much lower redline speed and tuning for lower power and higher efficiency. 

The "contour" lines show operating conditions of equal brake specific fuel consumption (BSFC, in grams of fuel consumed to produce one kilowatt-hour); this is of course output as mechanical power from the output shaft, not electrical power. The very best efficiency (lowest fuel consumption is at full load (producing 110 Nm of torque) and about 2250 RPM, which corresponds to about 25 kW. Remember that mechanical shaft power equals the product of torque and rotational speed, with whatever factors you need to make the units of measure correct (torque in Nm times speed in RPM divided by 2π). The "operating line" shows the set of points at which the Volt is programmed to operate: it generally stays just off full load and varies speed to vary output power, but doesn't go below 1400 RPM and throttles down to further reduce power at that speed.

This is for "charge sustaining" mode, which is essentially following the car's demand for power, rather than charging up the battery then taking a break. That may not be the mode you want to run in, but it illustrates the engine operating efficiency and how it depends on power output. In practice since the transaxle output shafts are not connected to anything, it would need to run in a different mode if using stock controls.

The detailed map is interesting, but the end result is what one would reasonably expect: for a given power output, run as slowly as possible by running at full load - that's how gasoline engines work. The other useful bit of information is that at what point of low power requirement should one shut down, run on battery, then restart later; what is the minimum power level for efficient operation or the single power level to run at in a cycling mode? In this case, on/off operation would be at 25 kW (110 Nm @ 2250 RPM), and if following the load then don't go under 1400 RPM and things get bad rapidly as load must be reduced to decrease output below 12 kW (80 Nm @ 2250 RPM). There is something to be said for not cycling excessively because the causes battery charge and discharge inefficiency, it would make sense to 

generally follow the electrical demand of the car
don't go above 42 kW (115 Nm @ 3500 RPM) for efficiency, which is about the MGA output and battery charging limits anyway
if power demand is below 25 kW and battery is depleted below some target (50% SOC?), run at the optimal efficiency point (25 kW, 110 Nm @ 2250 RPM) until battery hits a target high SOC (80%?), then follow demand
if power demand falls below some low threshold (15 kW?) and battery is already above high target, shut down and wait until a low SOC threshold to restart
If this looks like a pain to implement or not clear to understand, you can see how letting the stock system do its job has advantages. If it makes sense and seems easy, this might be an interesting aspect of the vehicle design to play with.

The second linked discussion also contains a similar map for the older and newer Prius engines showing similar behaviour, but highest efficiency below full load and better efficiency than the Volt engine.A non-plug-in Prius is nearly always in something equivalent to charge-sustaining mode because it has almost no battery. The Volt engine's fuel consumption translates to about 37%, while the Toyota engine peaks at just over 40%.


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## remy_martian (Feb 4, 2019)

*RPM times 2 pi (not divide) to get radians 

and RPM divide by 60 to get it on a revs/second baseline

So, pi/30 times RPM times NM torque

to get power in Watts

That efficiency chart is gold, Brian


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## remy_martian (Feb 4, 2019)

So...4 kwH for every kg of fuel burn and 3.5 miles/kWh (using my Bolt EV's efficiency and optimistically degrading 10% for the trailer) gets you 14 miles per kg of fuel. 

Need to degrade that by charging losses (heat). So call it 13 miles per kg.

2.7 kg per gallon of gas, so around 35 MPG

Buy a Prius, lol. The car, not the engine, because the Prius engine gets you to only 38 or so MPG.

Towing a trailer and the added weight of the vehicle is strictly novelty and of no practical use as an in-motion range extender.


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## joekitch (Sep 13, 2013)

remember, the objective isn't high efficiency, just "enough" efficiency for long distance highway voyages outside of good charging networks
i'd use this thing a few times a year, but the fact that i CAN use it means i don't need to have a separate car just for when the ev lacks the range i need

and again, this means only having like 100 miles of range isn't a problem, and i don't need to chop up the car to fit more batteries + drastically increase its curb weight just for some range i won't need most of the time


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## remy_martian (Feb 4, 2019)

You don't need to own a separate car. You *rent* one. A hybrid.

$400 a year for your vacation (or 12 days a year worth of beyond range trips). AND, you're not getting yourself closer to having to buy or build another EV because you're racking up the mileage. Running your own car for a 1600 mile trip costs about the same as a rental, and the rental is cheaper if you drive even more miles in those 12 days.


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## brian_ (Feb 7, 2017)

remy_martian said:


> *RPM times 2 pi (not divide) to get radians
> 
> and RPM divide by 60 to get it on a revs/second baseline
> 
> ...


That's right, of course - I even tested the formula with an example against the web-based calculator that I usually use, then just didn't check what I wrote out. Sorry for the confusion, and thanks remy_martian for catching that.

I'm trying to edit my earlier post to fix the error, but the forum software is throwing an error.



remy_martian said:


> That efficiency chart is gold, Brian


I had seen similar efficiency maps for Toyota and Mazda engines, so I searched for the Volt, and was pleasantly surprised to find one. If anyone finds the original source, I would interested in seeing the rest of the report or whatever it was in.


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## joekitch (Sep 13, 2013)

Efficiency maps are cool, although I'll need to find the stock fuel/ignition mapping for the volt to put on the megasquirt....
Somehow I doubt that's easily available online


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## brian_ (Feb 7, 2017)

remy_martian said:


> So...4 kwH for every kg of fuel burn and 3.5 miles/kWh (using my Bolt EV's efficiency and optimistically degrading 10% for the trailer) gets you 14 miles per kg of fuel.
> 
> Need to degrade that by charging losses (heat). So call it 13 miles per kg.
> 
> ...


It's true that any series hybrid has higher fuel consumption than a similar non-series hybrid or even conventional (non-hybrid) vehicle. The BMW i3 REX was a shocking demonstration of this when it appeared - it was hard to believe that such an advanced vehicle designed for efficiency could have such high fuel consumption, especially with such a tiny engine. The drag of the trailer would make the configuration even worse.

A generator trailer is intended to make an EV usable for occasional trips that would otherwise not be viable; if used routinely, it's the wrong solution.


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## brian_ (Feb 7, 2017)

remy_martian said:


> You don't need to own a separate car. You *rent* one. A hybrid.
> 
> $400 a year for your vacation (or 12 days a year worth of beyond range trips). AND, you're not getting yourself closer to having to buy or build another EV because you're racking up the mileage. Running your own car for a 1600 mile trip costs about the same as a rental, and the rental is cheaper if you drive even more miles in those 12 days.


I agree that the rental solution is better in most scenarios. Although I don't recall ever seeing a hybrid in a rental fleet, this should usually be a highway trip and that's not where hybrids are most beneficial anyway. The rental approach also allows a different size or type of vehicle (than the owned EV) to be used for these trips.


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## brian_ (Feb 7, 2017)

joekitch said:


> Efficiency maps are cool, although I'll need to find the stock fuel/ignition mapping for the volt to put on the megasquirt....
> Somehow I doubt that's easily available online


It would probably be the world's only application of aftermarket performance engine management to a Volt engine. Even the rest of the EcoFlex engines would not be popular tuning targets (they're in mostly economy cars, not sports cars), and the LUU variant has different enough characteristics that mapping would be different from other A14Xxx variants.

Those characteristics include peak torque near the maximum engine speed - this is visible as the top of the efficiency map rising nearly to the end of the speed range. This the combination of a moderately high speed of the torque peak and a very low maximum speed.


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## brian_ (Feb 7, 2017)

The A14XFL (LUU) engine is only used in the first-generation Chevrolet Volt (which is presumably what people are finding in salvage). The second-generation Volt (2016+) uses a similar engine from the Small Gasoline Engine family of engines which is replacing the Family 0; the one in the Volt is 1.5L L3A. The new engine is a newer design and has a higher compression ratio (than any other SGE variant or the LUU), so it is presumably more efficient; it uses direct injection (normally found only on turbocharged engines in this family) to make the higher compression ratio possible.


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## remy_martian (Feb 4, 2019)

brian_ said:


> I agree that the rental solution is better in most scenarios. Although I don't recall ever seeing a hybrid in a rental fleet, this should usually be a highway trip and that's not where hybrids are most beneficial anyway. The rental approach also allows a different size or type of vehicle (than the owned EV) to be used for these trips.


I get them all the time, when available - you do pay a premium over an ICE econobox and the breakeven on fuel seems to be around 400-500 miles. Either a Ford Fusion or a Toyota Prius. You can spec one if you search on kayak.com for rentals.


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## remy_martian (Feb 4, 2019)

While the Volt is convenient in having all the right pieces in one package, for the F-450 conversion I was looking into a baby turbodiesel, which is available in many small pickups and even, surprisingly, some large ones as well. Torque, baby! And, you can be carbon neutral by burning biodiesel in it, which we have available here locally at the pumps.

Those engines are all you see in SE Asia, pretty much, and are not as common here in The Greatest Country in The World™, though you can find some now and then.


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## brian_ (Feb 7, 2017)

remy_martian said:


> I get them all the time, when available - you do pay a premium over an ICE econobox and the breakeven on fuel seems to be around 400-500 miles. Either a Ford Fusion or a Toyota Prius. You can spec one if you search on kayak.com for rentals.


Good to know. I've never been offered a hybrid or seen that choice when booking, but this will depend greatly on location and I haven't rented very often (only about once a year) in the past few years. Even in Vancouver (where the Prius is the most common taxi) I wasn't offered a hybrid and didn't see one on the lot when I rented there last year.


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## joekitch (Sep 13, 2013)

well, if given the choice between 
-develop a charging trailer as a cool fun project which will then permit me to take my fun electric classic sportscar anywhere i wish
vs
-occasionally rent a boring modern car for longer trips

nine times out of ten i'm going for the former


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## brian_ (Feb 7, 2017)

remy_martian said:


> While the Volt is convenient in having all the right pieces in one package, for the F-450 conversion I was looking into a baby turbodiesel, which is available in many small pickups and even, surprisingly, some large ones as well. Torque, baby!


As I've noted before, I don't think the Volt is really convenient because it has parts which are not only unnecessary but could cause control complications. A Outlander PHEV is closer - just remove the superfluous drive motor and ignore the clutch and you have a 2.0 L engine geared to a 60 kW generator.

High torque for the power (meaning low optimal engine speed) is not an advantage in a purely series configuration (which the generator trailer would be); it doesn't matter what speed the engine needs to run, except that the lower the speed (and thus the higher the torque) the bigger the generator required in a direct-drive configuration (or the more step-up gearing ratio is required if stepping up engine speed to a more optimal generator speed).

I'm not sure what you consider "baby" - worldwide around 2 to 3 litres accounts for most of the light truck diesels (and this size is used in the Chevrolet Colorado and Silverado 1500, Ford F-150 and Transit, Ram 1500 and ProMaster, Mercedes Sprinter, etc), and while small by North American traditional practices that's very large for a generator trailer. If you want one set up for aftermarket applications, Cummins offers a 2.8 which is available as a crate engine (but not optimized for generator service).


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## brian_ (Feb 7, 2017)

joekitch said:


> well, if given the choice between
> -develop a charging trailer as a cool fun project which will then permit me to take my fun electric classic sportscar anywhere i wish
> vs
> -occasionally rent a boring modern car for longer trips
> ...


... and thus we have the reason for the continued existence of DIY Electric Car, even though it's no longer necessary to build a DIY project to have an electric car.


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## remy_martian (Feb 4, 2019)

"Baby" compared to the 6.4L that was in the 14,000 GVW truck


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## MattsAwesomeStuff (Aug 10, 2017)

joekitch said:


> -develop a charging trailer as a cool fun project which will then permit me to take my fun electric classic sportscar anywhere i wish
> nine times out of ten i'm going for the former


Yep, me too, and I'm interested in this for the same reasons 

Especially if it's a little trailer I could park vertically at the back of my parking stall when not in use.


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## remy_martian (Feb 4, 2019)

Seems you can't rent hybrids in Canuckistan.


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## brian_ (Feb 7, 2017)

remy_martian said:


> Seems you can't rent hybrids in Canuckistan.


Well, not readily in the places that I've gone recently. I haven't rented a car in Toronto (for instance) for about a decade, though. The Prius had been out for about a decade when I last rented in a major U.S. city, and I wasn't offered one there, either, but there are a lot more hybrid models now.


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## brian_ (Feb 7, 2017)

MattsAwesomeStuff said:


> Yep, me too, and I'm interested in this for the same reasons
> 
> Especially if it's a little trailer I could park vertically at the back of my parking stall when not in use.


Be careful with that idea - most engines don't like being tilted 90 degrees, so orient the engine appropriately, route vents and drains to work with that, and give the oil some time to drain down to the sump before starting after putting it down.


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## remy_martian (Feb 4, 2019)

Get creative with the motor mounts to keep the oily side down if you do it as a transverse 😂


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