gas generator trailer for EV's

[mctom987]

Has anyone here tried to plan/spec out a level 3 generator setup (25 kW output should be enough)? I understand it won't be cheap, but would love to build a trailer with a generator good enough for helping stranded drivers, and EV events.

25kw is ~34hp. You don't really ever want to run at 100%, so you'd probably want something around 70hp.

At 70hp, you're looking at a mid-range sport motorcycle engine. 650-800cc. Not nearly as small as a dedicated generator, though not nearly as heavy as the diesel gennies.

I've thought about doing something like this, and ultimately, it's just not feasible or cost effective. However, for the specific case of emergency support, you might be able to charge like $50 for the service to recoup your costs, while still be cheaper than a tow truck.

Long story short, you're probably looking at a $3000 setup. If you buy a commercial product in that range, they're almost always diesel, way larger than you can transport daily, and start around $6k.

 

[johnrhansen]

If you had a generator of approximately the right voltage range to put out battery voltage, you wouldn't need complex switching transistors, coils and the like. Just 6 rectifier diodes, and a low power control circuit for the alternator field to output the current the car is calling out for in a level 3 charge. maybe there's a 480 volt 3 phase generator surplus somewhere.

 

[mctom987]

Maybe… check a datacenter that is upgrading their UPS/EPS system.

480V 3P gennies tend to be quite expensive. $10k+ to start, and most can probably output the full 50kW charge. Definitely not something you could haul around though.

Who knows. This is interesting, so if you can find some sort of reasonable setup, it's definitely a new market. You also might be able to sell it to AAA or other services that offer gas delivery for ICE cars.

 

[lion]

Maybe… check a datacenter that is upgrading their UPS/EPS system.

480V 3P gennies tend to be quite expensive. $10k+ to start, and most can probably output the full 50kW charge. Definitely not something you could haul around though.

Who knows. This is interesting, so if you can find some sort of reasonable setup, it's definitely a new market. You also might be able to sell it to AAA or other services that offer gas delivery for ICE cars.

AAA already offers something like this in some areas (well they did a few years ago, haven't heard anything about the setup since). It was done by a company in NYC iirc, but they never responded to my e-mails.

I'm mostly interested in showing off the tech, help stranded EV drivers in the area, and use it during events which might be far away otherwise.

I guess we should start a new thread, as I don't want to derail this one, but I definitely would like to see a design that can be shared here. I'm not sure if 50kW vs 25kW is worth it, since it only charges at that speed while the SoC is low, and I'm guessing there would be a huge space/cost premium for 50kW.

Has anyone here tried to plan/spec out a level 3 generator setup (25 kW output should be enough)? I understand it won't be cheap, but would love to build a trailer with a generator good enough for helping stranded drivers, and EV events.

25kw is ~34hp. You don't really ever want to run at 100%, so you'd probably want something around 70hp.

At 70hp, you're looking at a mid-range sport motorcycle engine. 650-800cc. Not nearly as small as a dedicated generator, though not nearly as heavy as the diesel gennies.

I've thought about doing something like this, and ultimately, it's just not feasible or cost effective. However, for the specific case of emergency support, you might be able to charge like $50 for the service to recoup your costs, while still be cheaper than a tow truck.

Long story short, you're probably looking at a $3000 setup. If you buy a commercial product in that range, they're almost always diesel, way larger than you can transport daily, and start around $6k.

While $3,000 is expensive, it would be doable. Not aware of any commercial solution, unless you are talking about the diesel generators.

 

[JohnOver]

Maybe… check a datacenter that is upgrading their UPS/EPS system.

480V 3P gennies tend to be quite expensive. $10k+ to start, and most can probably output the full 50kW charge. Definitely not something you could haul around though.

Who knows. This is interesting, so if you can find some sort of reasonable setup, it's definitely a new market. You also might be able to sell it to AAA or other services that offer gas delivery for ICE cars.

AAA already offers something like this in some areas (well they did a few years ago, haven't heard anything about the setup since). It was done by a company in NYC iirc, but they never responded to my e-mails.

I'm mostly interested in showing off the tech, help stranded EV drivers in the area, and use it during events which might be far away otherwise.

I guess we should start a new thread, as I don't want to derail this one, but I definitely would like to see a design that can be shared here. I'm not sure if 50kW vs 25kW is worth it, since it only charges at that speed while the SoC is low, and I'm guessing there would be a huge space/cost premium for 50kW.

Has anyone here tried to plan/spec out a level 3 generator setup (25 kW output should be enough)? I understand it won't be cheap, but would love to build a trailer with a generator good enough for helping stranded drivers, and EV events.

25kw is ~34hp. You don't really ever want to run at 100%, so you'd probably want something around 70hp.

At 70hp, you're looking at a mid-range sport motorcycle engine. 650-800cc. Not nearly as small as a dedicated generator, though not nearly as heavy as the diesel gennies.

I've thought about doing something like this, and ultimately, it's just not feasible or cost effective. However, for the specific case of emergency support, you might be able to charge like $50 for the service to recoup your costs, while still be cheaper than a tow truck.

Long story short, you're probably looking at a $3000 setup. If you buy a commercial product in that range, they're almost always diesel, way larger than you can transport daily, and start around $6k.

While $3,000 is expensive, it would be doable. Not aware of any commercial solution, unless you are talking about the diesel generators.

If you are talking about attaching it to a truck, there are generators that attach to the power take-off (PTO) on the transmission of larger diesel rigs. I would think that a tow-truck sized truck would have a PTO. Maybe I'm misunderstanding your application. The big truck engines can easily make the 70 HP at 1800 RPM. I haven't looked into this kind of thing in a long time, but they were available for coach builders for fire trucks and (in my case) satellite uplink trucks. The whole package, since it didn't include the diesel prime mover, was quite reasonable.

 

[mctom987]

If you are talking about attaching it to a truck, there are generators that attach to the power take-off (PTO) on the transmission of larger diesel rigs. I would think that a tow-truck sized truck would have a PTO. Maybe I'm misunderstanding your application. The big truck engines can easily make the 70 HP at 1800 RPM. I haven't looked into this kind of thing in a long time, but they were available for coach builders for fire trucks and (in my case) satellite uplink trucks. The whole package, since it didn't include the diesel prime mover, was quite reasonable.

Something like http://www.electricgeneratorsdirect.com/Voltmaster-PTO30-25M-PTO-Generator/p5391.html?

While that would work great for AAA or tow trucks, it's not really something you could make use of with a Leaf in the back or a light duty trailer. A diesel genny is pretty much the only option.

This guy runs on LP and only weighs ~800lbs. Well within Class I towing limits, so it should be possible on a Leaf, even if it voids warranties. It only outputs 240V single phase though. Not sure how the DCFC things work, but you might be able to step-up, or just be satisfied with recharging up to 4 Leafs on L2 6kW.

A 480V 3phase generator costs almost double what the single phase costs. It's also a lot more efficient, so there's that. Probably because it runs on diesel, not LP. At almost 1800lbs, it's definitely outside the safe towing capacity of the Leaf. You would need Class II.


Keep in mind, even with these generators, you still need the L3 charger. The Leaf uses ChaDeMo, and it's not a simple connection like recharging a 12V battery is. This will add to your costs as well.

 

[TomT]

AAA already has mobile recharging trucks with both L2 and QC capability...

I've thought about doing something like this, and ultimately, it's just not feasible or cost effective. However, for the specific case of emergency support, you might be able to charge like $50 for the service to recoup your costs, while still be cheaper than a tow truck..

 

[JohnOver]

Something like http://www.electricgeneratorsdirect.com/Voltmaster-PTO30-25M-PTO-Generator/p5391.html?

Yep, or this: http://www.trexgenerators.com/pdfs/wincogen_catalog_2013.pdf (all made in Minnesota).