# 4x4 Conversion Feasible with EV?



## terrificKid (Sep 19, 2008)

I'm thinking about converting over a 4x4 van. Is this a feasible thing to do with EV? I am in no way a auto guy by any means, but from what I've _read_ it seems to me I would just connect the electric motor to the transmission like I would in a non 4x4 car. Are there electrical components or hydraulic systems involved in messing with transfer case or hub stuff that would make this too complicated or inefficient?

Thanks for the info!

-Tk


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## TX_Dj (Jul 25, 2008)

It seems you've picked two of the least desirable traits for an EV conversion... van + 4x4.  First of all, vans are heavy and not aerodynamic... weight and drag are the two biggest killers for EV range. Then you're going to add 1000+ lbs of battery (assuming you don't have the riches to afford bleeding edge lithium battery chemistry)... second, 4x4 adds a lot of weight and drag to the system.

Not saying it can't be done... just saying that unless you can afford about $40,000 worth of lithium, you won't get the same range as you would with $3000 worth of lead in a smaller, lighter vehicle.


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## Uncle Joseph (May 7, 2008)

Can it be done? Sure...the United States Government threw unlimited funds at NASA in the 60's to get to the moon in very short time, all things considered.

Would anyone here recommend that kind of vehicle? Not unless you have a veritable fortune to invest in all the top-tech products (AC Motor, lithium batteries, etc.). Not to mention that if you chose all those top-tech products, you'd be heading into some uncharted territory, and wouldn't have a lot of knowledge from other folks to build upon.

The motor/transmission adapter should be pretty standard fare. However, if you need a fluid pump for the transfer case, then you'd have to copy the method used for automatic transmissions. If you have an auto transmission and a transfer case, then perhaps a somewhat larger pump to drive the hydraulics could provide pressure for both systems. Although I'm not a transmission guy, so I wouldn't want to tackle this one.

Anyway, we'll all recommend a different vehicle. But if you have the cash (say $30k) then by all means, convert what will make you happy.


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## ElvishWarrior (Apr 10, 2008)

I think a 4x4 Van would be a great candidate for a conversion by someone willing to do double the conversion for double the vehicle. A full size van would offer the kind of room needed for the kind of parts you would need, unlike a modern midsize SUV that wouldn't have room for all the equipment required to move it. Figure a weight of about 5000lb, which is double that of the small cars more popular for EV conversions. You would probably be served best by a tandem motor setup, which would probably be best served by dual controllers. Using a regular size of battery pack, cut your range in half or double the battery pack. You may need a parallel battery pack anyway to cover the current draw required to move such a big vehicle.

Besides just doubling the conversion parts and work and working with a much bigger and heavier vehicle with heavier parts to pull and threaten to crush you, the biggest challenge may be the transmission. Manuals are highly recommended, and hardly any vans ever had anything but autos. I would swap it for a manual from a 3/4 or 1 ton truck, which may be work and cost intensive.

The result would be what one could possibly call the ultimate vehicle, something that can carry anything anywhere. You would of course have to drive VERY conservatively to keep from burning up your EV powertrain.

I'm looking at a light truck conversion and have a bare bones estimate of $5-6k (already have the truck) for a short range conservative speed vehicle. So you should probably be looking at $10-12k + vehicle just to get it rolling, with the possibility of some speed limitations. Instead of adding batteries for range, I'm planning to use a detachable range extending generator, as my trips are either real close to home or a fair drive away. Unless you plan to use your 4x4 van as a work vehicle for short range, a serious range extending generator would be worth serious consideration. For the power you'd need to move a van, a compact car engine might not be a bad idea. Efficiency and emissions would be much better than the small engines used on typical generators.

So if you want to break new ground and sink your teeth into a serious project, I think it would be really really cool. But if you just want a simple EV, think smaller.


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## TX_Dj (Jul 25, 2008)

Uncle Joseph said:


> Can it be done? Sure...the United States Government threw unlimited funds at NASA in the 60's to get to the moon in very short time, all things considered.


Great example. 



> However, if you need a fluid pump for the transfer case


Transfer cases are simple 2-speed unsynchronized (usually) gearboxes with a disconnect for the front axle. Nothing unusual required to have this in an EV conversion.

Yes... it is possible, as we've all said. Yes, you will have to have more of everything to equal the same range as half as heavy vehicle. No, it's not practical unless you have a legitimate need for a huge vehicle with 4x4.

Think about this- if you have a van with a 6000 lbs curb weight and an 8000 lbs GVWR (1 ton), you won't have enough cargo capacity to haul anything in the van once you fill it with lead, unless you do as Joseph suggests and go with Lithium batteries ($$$). Most of your vehicle's weight is related to its body, frame, and drivetrain. Yours has more weight in that category than most types of vehicles. If you were able to remove 800 lbs for your engine and its associated systems, you'd only have 2800 lbs to fit your motor(s), controller(s), batteries, assorted other devices, and you.

If you figure you want reasonable range, if you're going with lead, you'll likely need 2000-2250 lbs of battery to get a "reasonable range"... figure you'll need a bigger motor than a mid-size truck or small car, possibly two of them, and you're looking at 500 lbs of motors (with two). That leaves you with about 50 lbs for you, your cables, controller(s), charger(s), battery racks, etc before you're beyond the "legal weight". However, if you go with lithium, your pack may be closer to 900 lbs for the same capacity, but you're looking at more than $30k for batteries alone...

There are better choices available, and many people have done 4x4s and some people have done vans... but there are better choices available.


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