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Hello All,
I've been lurking on here for a few weeks now and I have to say, there is a TON of great info! This is my first post about my project, sorry about the lack of info.

My automotive skills are about average. No problem changing batteries or tires. But I've not tried anything more complicated. My electronics skills are above average. I can wire a house and build my own circuits.

We purchased a 2011 Mercedes Sprinter 3500 with the goal of doing an RV conversion. We got our Sprinter for a song because it doesn't run. A little more research revealed that the diesel in Sprinters are notorious for breaking down (over-engineered). I have been wanting to get an electric vehicle (looking into doing an EV conversion on my commuter car) and thought I would look into converting the Sprinter. Lo and behold, not only is it feasible, it *might* be cheaper than replacing the current diesel and will definitely be cheaper in the long run. Enough back-story, onto the good stuff.

The Sprinter comes with a 3.0L V6 Diesel that puts out 188 hp at 3800 rpm and 325 ft-lb at 1400 rpm. The weight ratings are: Curb weight 6196 lbs, Gross weight 9900 lbs, Payload 3794 lbs and Towing 5000 lbs.

I'm still debating between an AC or DC motor. I would love to hear all your thoughts on that. So far, it seems the consensus is that AC is better but DC is cheaper. I'm leaning toward doing a DC conversion for now. I've read a few forums on here where people have converted trucks and SUV's. How big of a motor will I need?

Clearly, as this is an RV conversion, efficiency and range are the most important factors. Not looking for performance. So we'll be spending most of our budget on batteries. Definitely looking into finding Leaf/Volt batteries or building my own.

Controller: If I go AC, going with the OpenReVolt unless you guys suggest otherwise. As DC is simpler, I haven't read up that much on DC Controllers.

My next big question is transmission. The sprinter is an Automatic and I can't figure out if it will be better to do direct drive or 2 speed.

Lastly, as this is an ERV conversion, I am planning to put some solar panels on the roof. I'm already planning to re-fashion the roof top piece above the cab to help with Aerodynamics. I was wondering if I have to keep the electric systems separate or if I can tie them together. This gets back to the AC versus DC discussion.

I can't wait to hear all your input!
 

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Hi
That is a big vehicle I'm using a DC system
I'ts great for having a lot of power cheap
But you are going to need continuous power - not just a few seconds until you reach the speed limit

DC motors are all re-purposed Forklift motors - mine is a big one (11 inch) and it is continuously rated at 10Kw
Running at a higher rpm will increase that - but even 30Kw will be too little for your beast
Running two motors might be enough - possibly with a tail wind

If I was converting an RV I would be looking for a motor/transmission from a crashed Tesla - or a Leaf although that might be marginal

I don't know of any of the "new" AC motors that would be big enough

If you are into electronics there are a number of people working on new "brain boards" to run the Tesla motor/inverter
 

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One option would keep the transmission and use an dual HPEVS AC-35 motor. With two 144 volt Curtiss controllers you peak at about 165 HP, which should give you at least stock-like performance if not more due to the wider and deeper powerband of the electric.

My main concern with this setup is how such a large vehicle can really suck some power going up a grade on the highway. Add a headwind, and you actually need high continuous power levels. Unfortunately, according to HPEVS the AC-35x2 only does about 70HP continuous.

A Tesla transaxle in the back would be great, but I suspect with the low floor of the Sprinter that you would need to raise the structure there to accommodate the Tesla setup.

With the Tesla in the back, you could use the center tunnel where the transmission, driveshaft, and exhaust are now for your battery pack, water tank, or whatever other heavy items you would like to keep low and centered in the vehicle. The engine compartment would gain a lot of space as well.

I am a fan of Sprinters, I look forward seeing your project progress.
 

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You are talking about peak power again - What is the AC 35 rated at for continuous? - I think it is 35Hp - 26Kw

It you have two of these in that size of vehicle you will destroy them
 

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You are talking about peak power again - What is the AC 35 rated at for continuous? - I think it is 35Hp - 26Kw

It you have two of these in that size of vehicle you will destroy them
Did you even read my post?

"My main concern with this setup is how such a large vehicle can really suck some power going up a grade on the highway. Add a headwind, and you actually need high continuous power levels. Unfortunately, according to HPEVS the AC-35x2 only does about 70HP continuous."

???
 

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We are just finishing a full Sprinter (Tesla style) conversion to all electric that has turned out pretty sweet, if you're still interested in conversion ideas.
 
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