# Suv conversions?



## joseph3354 (Apr 2, 2008)

the first thing you should probably ask is,are the owners pockets deep enough to afford such a conversion.for those specs you are going to need a lot of money.its going to cost at least 20k just for the batteries.the range and speed will require loads of energy and you are just not going to get it from lead acid batteries(read cheaper) due to the weight of the batteries that would be required.the electrical components needed for those specs can be had(read pretty expensive) and are possible to achieve.all that being said,here's a link for some conversions to maybe give you an idea of what you may require.

evalbum.com


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## Driftweed (May 10, 2008)

can it be done for $10k is what i am basically asking. I checked out that site you posted, looks like they did do a couple of heavier duty vehicles. However they didn't provide any specs. 

any help?


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## joseph3354 (Apr 2, 2008)

unfortunately no,because of the weight of the vehicles it would take a lot more than 10k to get the speed and range you are looking for.we just had a post on another thread estimating the battery needs of a vehicle similar in size and weight to what you would like to convert.i will get a link to that thread as soon as i find it.personally i think the numbers are a little high but not by much.

here you go: http://www.diyelectriccar.com/forums/showthread.php?t=13363


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## joseph3354 (Apr 2, 2008)

it appears i may have been mistaken in my assessment of your project.what you want may be feasible but probaly not for 10k.check this out!

http://www.evalbum.com/037


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## ga2500ev (Apr 20, 2008)

Driftweed said:


> can it be done for $10k is what i am basically asking. I checked out that site you posted, looks like they did do a couple of heavier duty vehicles. However they didn't provide any specs.
> 
> any help?


Where to start? How about the amount of energy necessary to accomplish the task? First off the range is vastly affected by both the speed of the vehicle and the weight. The amount of energy expended is vastly different if you're driving 85 MPH vs. 40 MPH.

So you need to clarify your range at what speed.

Now back to energy. One point that is often missed by novices is that gas has a lot of energy in it. This howstuffworks article:

http://auto.howstuffworks.com/question424.htm

Equates the usable amount of energy in a gallon of gas to 15 kWh. I really like this number because it can help us relate the size of a battery bank to gallons of gas.

Now the Red Beastie pointed out earlier can be helpful in sizing some numbers. The trojan T-105 battery is a 225 Ah battery @ 6V. So 40 of them would give a total energy capacity of 

225Ah*6V*40=54000 Wh

Now only 80% DoD on lead acid is allowed so the usable capacity is: 54000*.8 = 43200 Wh

So the "tank size" is 43200 Wh/15000 Wh = 2.8 equivalent gallons.

So the question is can you get 75 miles out of the equivalent of 2.8 gallons of gas?

The answer is unlikely. But it's worse because those 40 batteries weigh 70 lbs each. So that's a total of 2800 lbs and you haven't even gotten a passenger in yet.

According to this Caddilac page:

http://www.cadillac.com/cadillacjsp/model/po_specification.jsp?model=escalade&year=2008

The Escalade has a 5511 lbs curb weight and a 7000 lbs GVWR (max weight) so it can carry about 1500 lbs. But the batteries weight 2800.

That's a problem.

Now of course there are lighter batteries. One could carry lipos. They come in 3.2V, 200 Ah, 14.8 lbs packages. So to get the same 43.2 Wh capacity you'd need 43200/640 = 68 batteries. And the load would weigh a little less than 1000 lbs. LiPos can be run flat so you don't need any overhead.

The batteries are $400 each. So 68 of them will run you $27,200 for the pack.

We haven't even started talking about the additional power required to run the accessories. Or the fact that none of these SUVs have manual transmissions AFAIK. Both are additional challenges that will require even more battery capacity.

As much as we despise gas, it's a fuel with wonderous properties. I own a Yukon XL with a 32 gallon tank. That 32 gallons of gas that will cost me $115 (@ $3.60/gal) or so to fill up has the same energy capacity as 750 cell LiPo battery bank that weighs 5.5 tons and cost $300k.

When it comes to size, weight, and cost, we have to equate EVs with vehicles with 1-2 gallon tanks.

So when you ask "Can I move a 3 ton vehicle 75 miles @ 85 MPH on 2 gallons of gas?" I think the answer becomes pretty obvious.

It's very likely that you're going to have to cut down on each of your requirements:

1) You're going to have to drive slower.

2) You're going to have to limit your range.

3) You're going to have to drive a lighter, more aerodynamic vehicle.

The SUV simply isn't a good fit in the EV world.

There's currently a discussion in the blog area on this topic:

http://www.diyelectriccar.com/forums/showthread.php/why-suv-and-ev-make-perfect-8761.html

I think ElvishWarrior has the right thought process. While the SUV isn't the right fit for an EV, it could in fact couple well with one. Think more along the lines of have two different vehicles for different needs. A small, light, aerodynamic EV would be used as a short hop, 1 or 2 person, daily driver, while the SUV would be used for longer family outings. The fact of the matter is that is the situation I have now. My daily driver is a 93 Corolla that gets 33 MPG. I'm usually in it by myself, or with one or two of the kids. When we all need to go somewhere, we hop in the yukon.

Just some thoughts on the subject. Sorry to be the bearer of bad news.

ga2500ev


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## T3Tech (May 4, 2008)

Also take a look at these:
http://www.evalbum.com/1102
http://www.evalbum.com/1413

I've started thinking about converting my "totalled" Suburban and for weight comparison a 1 ton van comes pretty close. So far this is all I've come across in the way of heavier vehicles demonstrating that it can be done. So it's possible, but as pointed out the battery cost is the killer. 

I've pretty much decided that AC is the way to go for any conversion(s) I eventually get around to. Hopefully by the time it comes to it the cost of lithium batteries has come down some. Though going AC will eat up a good portion of 10k (if not more) just in the motor, inverter/controller, and related components. Whether that's going the single large motor route or with multiple smaller motors and using Curtis 1238's as I've considered (similar to this: http://www.evalbum.com/1396 ), the cost works out to about the same.

Unless you get lucky and come across some parts like what's in this: http://www.evalbum.com/1149


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## ElvishWarrior (Apr 10, 2008)

I'm in a similar boat calculating what would be needed for various SUV conversions. I'm looking to do a budget series hybrid conversion on a Bronco II.

Unfortunately, practically any modern SUV is going to be much heavier than the light truck based ones of not too long ago. You cannot find a modern truck based SUV weighing under 4,000lb, and even that just gets you a late model Blazer or Toyota FJ. Lots of people here put lots of time and money trying to get a 2,500lb compact car to get good range and speed.

Another thing you run into with SUVs is that none of the big ones have manual transmissions, in fact hardly any do at all. Auto transmissions are difficult for EV conversions due to different shifting points. Many people believe that more powerful motors or tandem motors used in direct drive would be a good solution for RWD or 4WD auto transmission vehicle conversions. I'm friendly to that idea, but also to the idea of getting back to man-trans (as I call them.)

I'm of the opinion that, like everyone else is saying, part of the solution to the fuel crisis is to drive differently. But my take is that it shouldn't be driving less, but driving in a different manner. Take all the recommended "hypermiling" techniques and make them your driving doctrine. I would feel more fuel friendly driving an Explorer conservatively than driving an Altima like a maniac. Maybe if people drove more carefully we wouldn't be so concerned about crash protection and be able to lighten the weight of our vehicles back to what they used to be.

Like others, I think you'll have to sacrifice some of your criteria here. Here's my suggestion on how to proceed:
1. Drop the maximum speed. If it can keep 60mph on a moderate highway hill or even gradually drop down to 50mph, that's be a speed people should be satisfied if they insist on driving a heavyweight.
2. Start with the Explorer. I think mid-size SUVs may be the best compromise for EV conversions due to having the space under the hood for a V8 with less total weight.
3. Consider using a manual transmission from a silimar sized vehicle.
4. Consider using a range extending engine+generator instead of an enormous battery pack for the longer range uses. I'm looking to fit a 15-20hp generator under the hood of my BII. For a full size SUV like the Tahoe and Escalade, a high efficiency 4 cylinder engine from a compact car may be a good under-hood range extender. An Explorer may end up being the unhappy medium with hood space.

What's driving my conversion specs is that I can't imagine a practical use of an SUV that doesn't involve a range extender. If I ever do a pure EV conversion, it would probably be an around-town car or light truck. Now if it's a work truck for around town, that would be another story, but I'm guessing these are personal vehicles.


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## tazdotnet (Apr 9, 2008)

one of the problems with SUVs is that they are not aerodynamic... there are also lots of little spaces for the air to get caught up in on the underside of the vehicle... some people have suggested lowering the vehicle and others have suggested placing something flat underneath the vehicle to cover the uneven surfaces... i however prefer my car as it weighs almost as much and is built like a tank (1984 caprice classic 2dr) it has suspension designed for small trucks (at least that is how it is listed)... these tips may help with the hybrid SUV also but i wouldn't know, i'm not an SUV person...


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## ElvishWarrior (Apr 10, 2008)

Good idea on the undersides. SUVs aren't unaerodynamic by definition, but the more complicated underpinnings do make a difference, especially when clearance is higher. A flat panel underneath may offer some improvement, and could be spun as a win-win for protecting the underside.
One advantage of trucks for EV conversions is the frame-on-body design, which usually allows easier improvement of the suspension for battery weight and even some space in the frame to put them without starting to intrude on cabin or trunk space. That might even make a body lift start to look attractive, as long as it had enlarged wheels to make it worth it.
Lowering an SUV to me is heresy. If you need the size and capability, don't cut it back. If you want a lower, more aerodynamic vehicle, cars are a better choice.


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## outlooker202 (Jul 16, 2008)

here is a article where a 88 Jeep Cherokee was converted. It very detailed except it doesn't list price and man hours required to finish that project

http://www.driveev.com/jeepev/home.php


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## joseph3354 (Apr 2, 2008)

here is a fairly complete rundown on that jeep. enjoy! 

http://evalbum.com/589


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## GaryTaylor (Aug 27, 2021)

ga2500ev said:


> Where to start? How about the amount of energy necessary to accomplish the task? First off the range is vastly affected by both the speed of the vehicle and the weight. The amount of energy expended is vastly different if you're driving 85 MPH vs. 40 MPH.
> 
> So you need to clarify your range at what speed.
> 
> ...


Hi, the weight you've mentioned, have you taken into consideration the weight saved minus engine, gearbox and fuel tank?


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## Kato659 (Aug 5, 2019)

GaryTaylor said:


> Hi, the weight you've mentioned, have you taken into consideration the weight saved minus engine, gearbox and fuel tank?


The person you're quoting last posted in 2016. 

I don't think his numbers accounted for the removed weight, though with such a heavy Lead Acid pack it doesn't change the math by very much. Depending on the particular engine and gearbox, the weight removed can vary by a couple of hundred pounds, but with the pack described above you would still exceed the weight rating on the vehicle.

13 years on since this thread was last active, Lead Acid is now seldom used. Many of the challenges with a large vehicle remain, however.


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