[Swankierdust119]

So I plan on doing a somewhat EV conversion to my 93 Bronco. This is my work vehicle but I’ve got a few questions. I’m planning on basically making it like a train, running an engine that turns a generator onboard to power the battery and motor. I want to iterate this is not a Hybrid. The engine will never power the drivetrain directly, only the battery and motor. The main reason I’m looking into this is the extended range of a generator powered EV and the torque that I could gain by going EV. The main reason for range is I live out in the countryside of the Southern United States but I don’t have the money to buy essentially a Tesla Cyber Truck with the tri motor setup. Now on to the questions, got a little side tracked.

1) has anyone on this website done something like this? If so, how’d it go? Any complications/regrets?

2) what would be a good motor to run with for something of this setup? I would like one that is lightweight but still a workhorse that’s somewhat efficient.

3) about what size battery would be good for a setup like this? Maybe one with about 50 miles of range Atleast for when the fuel tank runs out but is there any specific brands or companies to look for?

4) and finally what should I look for to convert this to a somewhat EV? (This is the first time I’m doing anything close to this and don’t want to mess up terribly)

 

[piotrsko]

Rules of thumb: weight of vehicle divided by 10 to get watt hours per mile thus battery size.
Going to need a genset that does say 240VAC at least 100 amps, 3-400 is better so you're talking a 6 cyl diesel Onan out of a big motorhome..$$$$.

Kinda like being your own level 3 charger. Not sure if the bronco can deal with the size and weight, definitely not offroad.

Not saying don't do it, just be aware why you'd be the first to do this.

The train people do this with big diesels that displace more in one cylinder than the typical american race engine total, and have generators that can power buildings

 

[MesquiteTim]

bad idea - efficiencies are lost each time you convert energy

Your plan:
convert gasoline to recip engine
convert recip to turn a AC generator
AC gen converts hp to electricity
electricity powers battery charger
battery charger converts AC to DC
inverter converts DC battery to motor
electric motor turns drivetrain
drivetrain drives wheels

Better plan:
convert gasoline to recip engine
convert recip to turn a AC generator
AC gen converts hp to electricity
electricity powers battery charger
battery charger converts AC to DC
inverter converts DC battery to motor
electric motor turns drivetrain
drivetrain drives wheels

** charge at home at night instead of carrying your engine/gen "grid" around with you. There is a reason, a good reason, that NO ONE does it your way.

 

[Electric Land Cruiser]

Probably not wise to convert your work vehicle as your first conversion because even in the best of scenarios it will be inoperable for months on end. My recommendation is make something EV first and then add a generator once it's working.

 

[MesquiteTim]

Agreed. The '93 Bronco is a huge brick. Look for a smaller car. My first one was VW transaxle based to make the adaptor as simple as buying a kit.

This would be a cool build:

 

[brian_]

I’m planning on basically making it like a train, running an engine that turns a generator onboard to power the battery and motor. I want to iterate this is not a Hybrid. The engine will never power the drivetrain directly, only the battery and motor.

But that is a hybrid; specifically, it is a series hybrid.

Wikipedia: Hybrid vehicle drivetrain / Series hybrid
Center for Advanced Automotive Technology: HEV Types
Parker: Series Hybrid Vehicle System Design
UCSUSA: Series vs Parallel vs Series/Parallel Drivetrains

Aside from assisting understanding of these terms, these references should help understanding of the design factors to consider in building an effective series hybrid system.

 

[brian_]

There is a reason, a good reason, that NO ONE does it your way.

Well, almost no one. The Fisker Karma used this design, the BMW i3 REX is a series hybrid if using the engine, the Honda Accord Hybrid runs in series mode except at highway speed, and the Nissan e-Power system is a pure series hybrid.

I agree that it's not the most efficient hybrid configuration, and makes sense only in some specific circumstances. Doing it with decent efficiency requires careful optimization of all of the components.

 

[MesquiteTim]

Ok, let me rephrase it. No one does a hobby conversion this way. Happy brian?

(since this is a DIY electric car forum, I assumed that it was implied)

 

[brian_]

Going to need a genset that does say 240VAC at least 100 amps, 3-400 is better so you're talking a 6 cyl diesel Onan out of a big motorhome..$$$$.

A six-cylinder genset in a motorhome? Try one or occasionally two cylinders. My 5500-watt Onan is a two-cylinder. That largest RV genset would be a 12 kW (50 A @ 240 V) to match the typical Class A motorhome electrical capacity.

Yes, 400 A @ 240 V would be 96 kW and vastly larger than my Onan, and would have more cylinders, but you won't find one of those in any motorhome; the largest Onan for an RV is a 8 kW 3-cylinder diesel... and even it weighs 794 lb (361 kg) and won't fit in many large motorhomes. A six-cylinder 100 kW genset sits in a building, or occasionally is found on a trailer or mounted to a large truck for industrial use; it weighs about the same as the entire Bronco, and would never be in any RV.

A series hybrid doesn't need an engine sized to meet peak power demand, only one large enough to run efficiently at average power demand - the battery smooths out power flow. Industrial gensets are too heavy; the smallest car engine one can find, tuned for efficient running at constant moderate speed, is suitable for a series hybrid system for a light truck. BMW uses a 650 cc 2-cylinder maxi scooter engine in the i3 REX (and it gets lousy fuel efficiency).

 

[brian_]

Ok, let me rephrase it. No one does a hobby conversion this way. Happy brian?

(since this is a DIY electric car forum, I assumed that it was implied)

No, that wasn't really implied. As an EV forum, any hybrid is outside of the forum's intent... and despite that many people have come in with some sort of hybrid proposal. A few of them are series hybrids. No, they don't get built, but when giving examples of what is done for EV conversions, many examples are from production EVs (which are all better designed and built than any backyard project), not just from other DIY projects.

 

[brian_]

2) what would be a good motor to run with for something of this setup? I would like one that is lightweight but still a workhorse that’s somewhat efficient.

Motor weight is small compared to everything else, so keeping the motor weight down is not normally a high priority.

3) about what size battery would be good for a setup like this? Maybe one with about 50 miles of range Atleast for when the fuel tank runs out but is there any specific brands or companies to look for?

You could use production plug-in hybrids for examples - they normally run 8 kWh to 16 kWh battery capacity, and 50 miles is the top end of the battery-only range of these vehicles.

4) and finally what should I look for to convert this to a somewhat EV? (This is the first time I’m doing anything close to this and don’t want to mess up terribly)

Converting to a pure battery-electric EV consists of increasing the battery capacity and removing the generator set (engine and generator). You might consider how an additional battery pack might go where the generator set was, and how you would re-configure the battery to use this additional pack space.

 

[brian_]

1) has anyone on this website done something like this? If so, how’d it go? Any complications/regrets?

It is often proposed, and rarely if ever actually built... perhaps because people realize how poorly it will work.