Series Hybrid Build

[Seeker]

So I have this idea. EV is changing the car world, but it hasn’t appeared in the off road world yet, to my knowledge. As we all know, our TJs aren’t the best on gas, especially lifted and with tires. I get 14mpg highway on 35s and a 4in lift.

to address this issue, I’ve been thinking of creating a series hybrid drivetrain to increase MPG and torque. Both of these things would increase off road performance. Imagine being able to tap into 100% tq on the trail at all times.

I see several advantages right out of the gate here. The need for axels, axel tubes, differentials, transmissions, transfer cases, and lockers would be totally unnecessary. It would all be controlled on the hubs by electric motors and software.

For those who don’t know, a series hybrid uses an internal combustion engine (referred to as ICE for the remainder of thread) to power a generator that powers the motors and charges the battery bank when needed. This means the ICE doesn’t run full time, and only runs at its most efficient RPM when it does. The batteries power the motors and relies on the ICE to be charged when needed. A parallel hybrid still has an ICE that is attached to the drivetrain which lowers its efficiency.

I will have to dyno my Jeep to see how much power and TQ it currently makes to source a generator of equal output, but standard power use of a vehicle is 15-20kw to move on a series hybrid design.

With that said, to get the most efficiency, you’d want to upscale that number to reduce fuel consumption, so I’m thinking a 30kw diesel generator. This would consume 2 gallons an hour on a generac diesel generator. So in theory, at highway speeds (70mph) that would be 35mpg. Or over double my current fuel consumption at a minimum if the engine runs all the time, which isn’t how the system works.

Now that we have the benefits listed, to a somewhat degree, it would only be fair to discuss the drawbacks.

I would have to design a custom hub at each wheel to hold an electric motor, suspension mounts, sway bar mounts, brakes, wheel bearing, and studs. This is if I wanted to totally delete the axels and axel tubes. Cost is another issue, as generators are not cheap and neither are batteries. System management would rely on a MoTec ECU as they offer hybrid support, but that is also expensive, but it comes totally customizable with traction control support as well (lockers and LSD for daily use). Weight would also be a factor as subtracting an engine, trans, and transfer case would be replaced by a generator and a battery bank; neither of which are light. The weight may be offset, or it will increase.

All in all, I think it would be a fun project and be the first of its kind. If desired I can site a thesis paper on EV.

 

[AndrewLJR]

Pretty neat idea if you have the knowledge and ability to make it all work. Other than the obvious concerns, the first I thought of was exposing the hubs/motors to the elements we typically when wheeling.

 

[jhetcel23TJ]

Buy one of these and put a jeep tub on it https://bollingermotors.com/bollinger-e-chassis/

 

[Chris]

I agree, if you have the knowledge and ability to make it all work, this would be one hell of a cool build.

 

[Seeker]

Buy one of these and put a jeep tub on it https://bollingermotors.com/bollinger-e-chassis/

While that would be the easiest solution, my goal is to retain the Jeep frame and mounting points for most of the suspension and steering components. This way I can replace things that brake cheaply.

 

[Seeker]

Pretty neat idea if you have the knowledge and ability to make it all work. Other than the obvious concerns, the first I thought of was exposing the hubs/motors to the elements we typically when wheeling.

Yeah that’s a major concern of mine as well. Luckily modern electric motors are weather proof. The issue would be hiding the wiring to the motors in a way it can’t get snagged on a trail. My idea is to run the wiring behind the motor and then up the backside of the struts.

As far as ability and knowledge goes, I think I got that covered. If I run into roadblocks I have friends who are electrical engineers to assist.

 

[B00mb00m]

I'd love to see it done, hope yo ugo through with it. I like the hybrid aspect of it also vs pure electric, just for range. So if you get rid of the axles what are you going to be doing for suspension? The easiest implementation would be electric motor placed at each driveshaft and then you can keep it mostly traditional suspension options.

Have you seen the ElectricGTE setup where they have a smallblock sized electric motor package that plugs into oem style drivetrain. That's what we'll need to make electric swaps commonplace among jeeps IMO.

 

[Seeker]

I'd love to see it done, hope yo ugo through with it. I like the hybrid aspect of it also vs pure electric, just for range. So if you get rid of the axles what are you going to be doing for suspension? The easiest implementation would be electric motor placed at each driveshaft and then you can keep it mostly traditional suspension options.

Have you seen the ElectricGTE setup where they have a smallblock sized electric motor package that plugs into oem style drivetrain. That's what we'll need to make electric swaps commonplace among jeeps IMO.

It would be simpler to just throw an electric motor on each axel, but my goal is to eliminate as much drivetrain lose as possible. As for suspension, it would be similar to independent suspension front and rear. It’ll have to be a coil over conversion to the hubs, just like that in sports and race cars. That way I can eliminate the need for axel tubes. In essence the Jeep suspension would have to be totally custom.

I do plan on making this build, and while it’s happening I’ll create a spreadsheet with the needed parts and cost of each. I’d like to release that information at the end of the build after it’s been thoroughly tested so the Jeep community can replicate it. Maybe sell a kit with all the nessicary parts as well?

I honestly think this will help extend our TJs life span into the future.

I’d like to be able to create a price point for different fuels such as diesel, gas, and propane since they are easily acquired world wide. Maybe do back to back resting of each fuel for the generators running on the same motors, batteries, and suspension set ups to see which is the most MPG and which is the cheapest per 100 miles.

So far I’ve decided on a 30kw diesel generator, preferably generac as it uses a Perkins 2.2L turbo diesel ICE, 2 Chevy Bolt battery banks, and possibly Tesla S motors on each axel, since Tesla uses 2 motors for its 4wd. I know I can get forklift motors much cheaper, but they aren’t as weather tested as the Tesla motors, but they are smaller and can be built into a hub. For the brains of the operation I’ll have to contact MoTec to see if they’re electric controller can handle 4wd. If not then I’ll have to raspberry pie it and develop my own firmware which will be the most time consuming part.

It seems the easiest way would be to make the Jeep independent suspension front and rear and have axels running from a center mounted electric motor with custom hubs to mount the suspension to.

Here is my current price layout:
30kw diesel generator - used 3,000-5,000. New 7,000+
Tesla motor: used 1,600-2,000 x2
Batteries: Chevy Bolt battery new 3,000 used ~750-1,500 x2 (possibly)
MoTec ECU - 2,000 (if they support 4wd. If not then raspberry pie)
Inverter (converter) - varies (estimate max new 2,000)
Time - undetermined

 

[B00mb00m]

It would be simpler to just throw an electric motor on each axel, but my goal is to eliminate as much drivetrain lose as possible. As for suspension, it would be similar to independent suspension front and rear. It’ll have to be a coil over conversion to the hubs, just like that in sports and race cars. That way I can eliminate the need for axel tubes. In essence the Jeep suspension would have to be totally custom.

I do plan on making this build, and while it’s happening I’ll create a spreadsheet with the needed parts and cost of each. I’d like to release that information at the end of the build after it’s been thoroughly tested so the Jeep community can replicate it. Maybe sell a kit with all the nessicary parts as well?

I honestly think this will help extend our TJs life span into the future.

I’d like to be able to create a price point for different fuels such as diesel, gas, and propane since they are easily acquired world wide. Maybe do back to back resting of each fuel for the generators running on the same motors, batteries, and suspension set ups to see which is the most MPG and which is the cheapest per 100 miles.

So far I’ve decided on a 30kw diesel generator, preferably generac as it uses a Perkins 2.2L turbo diesel ICE, 2 Chevy Bolt battery banks, and possibly Tesla S motors on each axel, since Tesla uses 2 motors for its 4wd. I know I can get forklift motors much cheaper, but they aren’t as weather tested as the Tesla motors, but they are smaller and can be built into a hub. For the brains of the operation I’ll have to contact MoTec to see if they’re electric controller can handle 4wd. If not then I’ll have to raspberry pie it and develop my own firmware which will be the most time consuming part.

It seems the easiest way would be to make the Jeep independent suspension front and rear and have axels running from a center mounted electric motor with custom hubs to mount the suspension to.

Here is my current price layout:
30kw diesel generator - used 3,000-5,000. New 7,000+
Tesla motor: used 1,600-2,000 x2
Batteries: Chevy Bolt battery new 3,000 used ~750-1,500 x2 (possibly)
MoTec ECU - 2,000 (if they support 4wd. If not then raspberry pie)
Inverter (converter) - varies (estimate max new 2,000)
Time - undetermined

I think if your project requires making a jeep IFS you won't find a large audience of interest. A lot of us will have spent MANY hours and dollars dialing in our suspension just right and when I want to extend my LJ life with a motor swap i surely wouldn't want to cut off my suspension and start over. IMO if you want IFS start with an IFS platform like T4R, a lot of those overlandy folks would love the hybrid.

 

[Apparition]

Tagging in. I’d also like to see 4 motors one at each end of the solid axles maybe make them portals if further reduction is needed.

 

[Seeker]

I think if your project requires making a jeep IFS you won't find a large audience of interest. A lot of us will have spent MANY hours and dollars dialing in our suspension just right and when I want to extend my LJ life with a motor swap i surely wouldn't want to cut off my suspension and start over. IMO if you want IFS start with an IFS platform like T4R, a lot of those overlandy folks would love the hybrid.

The goal is to make it bolt on for the hubs to accept the same coil over suspension (if they have it) or offer a coil over package with the kit.

I agree that it won’t draw a lot of attention for a sale item, but I want to do this to prove it can be done and a budget price for such a build.

I’ll have to do a deep dive into the suspension design on my Jeep and see if I can design a hub that will keep the original suspension. Not holding any hopes though as the axel tubes are a major weight distribution factor in it. Personally I’d want to retain my current suspension set up if I can to lower the cost of the build.

 

[Seeker]

Tagging in. I’d also like to see 4 motors one at each end of the solid axles maybe make them portals if further reduction is needed.

I need to do further research on 4 hub mounted motors. Right now I know a center mounted IFS IRS set up with Tesla motors will work. I’d like to have hub mounted motors personally, but the size of the motors and the need to (hopefully) retain stock suspension mount points would mean the motors would be a stressed part.

 

[B00mb00m]

The goal is to make it bolt on for the hubs to accept the same coil over suspension (if they have it) or offer a coil over package with the kit.

So not IFS? Sketch something out for us, pictures are worth many words.

 

[Seeker]

So not IFS? Sketch something out for us, pictures are worth many words.

I’ll work on that tonight. Both of my ideas would be IFS. The difference would be the motor placement locations and the need for axels or not. 1 motor per hub would eliminate the need to an axel but a 2 motor center mounted location would require axels.

In the second idea, the motor would be mounted to the tub or frame and have axels with a U joint running from each side of the motors to the hub. This is the way IRS works on cars. No actual axel tube, but bare axels exposed that run to joints.

 

[BuildBreakRepeat]

I’ll work on that tonight. Both of my ideas would be IFS. The difference would be the motor placement locations and the need for axels or not. 1 motor per hub would eliminate the need to an axel but a 2 motor center mounted location would require axels.

In the second idea, the motor would be mounted to the tub or frame and have axels with a U joint running from each side of the motors to the hub. This is the way IRS works on cars. No actual axel tube, but bare axels exposed that run to joints.

I think an axle-less but not independent (thinking like a strong trailer axle with the motors on each wheel) would perform much better and get much more love than IFS or IRS

 

[scottgraham]

@Seeker
There is on off-road EV, google Ken Block and KOH maybe.
He demo drove it, more of a dessert racer from what I recall.
Maybe get some ideas from it.

 

[Seeker]

@Seeker
There is on off-road EV, google Ken Block and KOH maybe.
He demo drove it, more of a dessert racer from what I recall.
Maybe get some ideas from it.

Yeah I’ve seen it. It’s pretty neat, but I’m going for a trail rig, not a desert racer. I would LOVE to build a Baja 1000 race Jeep though, but that’s for future projects.

I apologize for not posting the schematics yet. Work has been busting my ass, but I will tomorrow! Get ready to see some really crappy art work.

I brought this idea up to my dad and he said if I could make it cheaper and for side by sides that it would probably sell well. I don’t know much about the side by side communities, but I would like to develop something for them after this build.

 

[Zorba]

How bad of an efficiency hit would it be to eliminate the battery altogether? Run like a ship or diesel electric locomotive? Batteries suck!

 

[Aaronroy]

Did you ever get anywhere with the series hybrid build? Very interesting idea and something I'd consider for my TJ in the future.