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Discussion Starter · #1 ·
I'm very new to all of this, but very interested in converting my 2003 Honda pilot to an EV. I have little to no experience in auto mechanics or electronics, but do have friends that work in the industry willing to help. I would like to keep it AWD as it is and get anywhere from 60 - 100 miles per charge. I would also like it to still be able to pull maybe a small boat. Hope that's not impossible. I'm really not sure how much to expect to spend, but I'm hoping anywhere from $10,000 to no more $20,000 to fully convert it. I live in Alaska so it also needs to be able to work in extreme cold conditions. What kind of motor should I use? How much should I expect to spend? Please help with any info you can provide.

Thank you!
 

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Discussion Starter · #3 ·
Wow really? Is that because of the distance I want or the size of the vehicle? How much would a battery like that weigh? Do you have any suggestions on what kind of motor to use or what I should expect to spend on it?
 

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Just as a ballpark guess, given the 4000# plus weight, AWD, and wanting 60+ mile range you are talking about at least 156v worth of 200ah cells, or perhaps a parallel pack of 160ah cells..... $15k or so, plus $7k of electrics with an 11" DC motor and middle of the road 500amp controller like a Curtis, plus some skilled labor for the welding and whatnot. Going AC or with high end controller or charger would drive the price up significantly more...

oh... and is the Pilot standard or automatic?
 

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You could (and would have to) build insulated battery boxes as well in your situation. These don't dramatically add to the cost of a conversion (insulation and heaters are cheap) but they would add to the volume necessary for batteries.

However, winter driving means more energy used for heat, defrosting, wipers, lights, etc. And you will likely be plowing through rain and (in your case lots of) snow and all this going on at once can impact electric range by 20 to 30 percent easy. AWD will be a 5 to 10% tax on range as well but in your case maybe a requirement.

One thing that might be working in your favor: What kind of speeds are you looking at for that 60 mile (minimum) range? If it is mostly at non-freeway speeds (secondary roads and such) and not too hilly you might be able to get away with a somewhat smaller battery pack than if you wanted that 60 mile range at 60mph. As a real world example, my MR2 can do 50 to 60 miles at 60mph straight and level. If I could drive continuously at 40mph under the same conditions instead (depending on where in AK you live, quite possibly a more realistic situation for you than for me) the range would be in excess of 100 miles easy. This effect is largely due to the square law of wind drag (doubling speed quadruples wind drag) but also in my case there is a factor due to the lead acid batteries and their peukert effect which would be much less pronounced with lithium batteries.

You could also consider a smaller vehicle. As for towing, a "small" boat is a relative term but assuming no more than 2 or 3 thousand pounds there are smaller vehicles that would still seat 4 and tow the boat after being converted.

If you do have significant hills, then with the towing requirement an AC drivetrain might be very well advised for the regenerative braking ability. There is no "engine braking" in the typical DC powered EV. At the very least, ensure the boat trailer has brakes.

I am starting to theorize what my second EV is going to look like, and I want it to be able to seat 4, tow around 2000lbs and have decent cargo space. In other words, similar to what you are thinking. FWIW here is my very preliminary plan: I intend to use a solectria AC55 for the motor with direct drive using around a 6:1 gear ratio, and enough batteries for a 100 mile nominal range at freeway speed (at least 30KwH usable) My very preliminary current list of candidate vehicles: Pontiac Aztek (the heaviest but also with the most fat to lose up front, and also my favorite at this point), PT cruiser, Chevrolet HHR, Mazda 5, Scion xB (by far the lightest). I am expecting to be spending around $25K on the build, mostly for the batteries. I already have the motor and inverter (lucky craigslist buy) and I will recycle the manzanita charger from my current car.

Good luck
 

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Discussion Starter · #6 ·
The pilot I'm planning to convert is a 5 speed automatic with a rear locking differential. So I should be looking for an ac drive system because of the area I live? There are a lot of hills around here and would hate to setup with a Dc system and then have problems uphill especially in the winter. Is there somewhere I can get prices and specs that would work? I'm sure this will make my venture a much more expensive one. I was looking at www.currentevtech.com. Would the 120kw BLDC motor work in my situation?
Thanks again for all the helpful info!
 

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The pilot I'm planning to convert is a 5 speed automatic with a rear locking differential.
automatic is possible, but more complex and more expensive. you have to add a pump and get into the electronics to set shift points, etc.... there are threads on what is involved, and you'll see it complicates things.

If you decide to go AC you may be able to use fixed gearing and skip transmission to get around this issue, but you will sacrifice either low-end acceleration, or limit your top speed.....
 

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as for motor sizing, 120kw is about 160 horsepower. And dtbaker is right about the tranny. If you are going to keep it, go to a manual. You could possibly stay clutchless to keep the conversion simpler. You would use it more like a range selector: 2nd on the hills, 3rd on the flats most likely. Unless the pilot or a similar AWD system came with a manual, doing the swap might be a pain though. If your AWD transfer case has a low/high range though then there is your range selector.

The motor you are looking at has plenty of torque (635nm peak or about 450 foot pounds, yeesh) but a fairly low max RPM (5000) so if you were doing direct drive, a 6:1 gear ratio would be the best you could do. That would give you a maximum speed of about 65mph.

With all the hills you are back to needing a pretty hefty (but quite achievable) battery pack to get the range you want. If you assume a very conservative 500wh/mile with a boat in tow and some hills, a 30KwH usable capacity pack would give you 60 miles of range. Under better conditions (fewer hills, no boats) and not screaming along too fast that same battery pack might give 80 or 90 miles of range.

Good luck.
 

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Discussion Starter · #9 ·
The shifter has gear 1, gear 2, gear 3, then drive. I know it also has a button you can push that switches the speed that the AWD will operate at (mainly used when stuck in snow). Would I be better off getting a project SUV with a manual transmission? Would it be easier in any way if I went with 2 drive systems, one for the front axle and one for the rear?
 

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Sounds like your pilot is true AWD without a low range in the transfer case.

Yes, a manually shifted vehicle is frequently a better candidate than an automatic, all else being equal.

Lots of people have talked abouit building hybrids out of AWD / 4WD vehicles by putting a motor on one end and leaving the ICE driveline on the other. A very few have actually done it. To the best of my knowledge, nobody has been really successful at it. My take on that approach is if you want a hybrid SUV, go buy one. The ford escape hybrid gets around 30mpg's I think. Not bad for an SUV.

BTW, I have been continuing my own research and it is pretty clear the best vehicle for conversion of the bunch I listed in an earlier post is the scion Xb. 0.8 CdA (m^2) and stock curb weight of about 1100kg or 2400lbs. The stock curb weight is comparable to my MR2's, and the CdA is not that bad. Many pickups, SUVs and Minivans are well above 1.00 in that measurement. The Aztek is at 1.36.

Good luck.
 

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I didn't see what make/size boat you have. What do you consider "small"? Max required torque will depend on that. If you didn't already, find specs for your vehicle to determine max or peak torque of the existing engine and the gear ratios. I would guess the largest torque requirement is when you pull your boat out of the water up a ramp, and that you do that with the vehicle in first gear. Can you do it in second? That will bracket somewhat the required motor torque & gear ratio (wheel torque). Then you have a bound for what electric motor peak torque and gear ratio you would require for this if you use a fixed gear ratio. You may find that to have enough torque to pull the boat up the ramp you require a gear ratio that limits your top vehicle speed to a lower value than you would like. You can estimate the latter from max motor rpm for continuous duty, gear ratio, and tire diameter. If you use an AC motor with higher max rpm (higher than you could use with a series DC motor, which I think is around 4k to 5k rpm continuous depending on the size motor, but others here would know that better) and fixed gear ratio, it must have high enough continuous power rating at the higher rpms to move the vehicle and boat at the higher speed you desire. That may well require an AC motor with power which will be hard for a diyer to find and very expensive if you do - unless the boat is something light like a small (say 14 ft) aluminum fishing boat. If you have to pull the boat at higher speeds (say > 50 mph) up steep grades (say > 4%) that will be very demanding for required power at higher motor rpm. It would be much easier and cheaper to find a suitable motor/controller for a vehicle with a transmission.
 

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Discussion Starter · #12 ·
The boat is 14 ft and homemade of wood. I don't know the weight of the boat, but I'm guessing it's about 1 ton with trailer. Is it not possible to convert with an auto trans? I guess I'm just having a hard time understanding the mechanics of why? I've been looking at some ac motors on www.metric mind.com. They are much more expensive, but seem to be what I need with the mountains and hills all over. How hard is it to convert to direct drive? I need to weigh cost of trying even if it's possible with my honda pilot or getting a project car/SUV with a manual transmission.
Thank you for all the help!
 

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HI all, first post. Regarding "Lots of people have talked abouit building hybrids out of AWD / 4WD vehicles by putting a motor on one end and leaving the ICE driveline on the other. A very few have actually done it." It has been my dream to make a hybrid out of my 08 Honda Pilot.
First of all, 13-16mpg in the city really sucks and I bought it right before gas spiked at $5+ per gallon. My Pilot is a FWD and what I discovered is that the rear end is configured for a differential. I thought a simple electric motor and axles to the rear wheels would be fairly easy and the battery pack could be located where the drive shaft should be. I was thinking low profile lithium ion batteries instead of bulky deep cycle lead acid batteries. Anyway, I imagined the e-motor providing a boost at launch from red lights and such then revert to gen mode scavenging a minimal charge from the rear wheels until the brakes were applied then engaging as a regenerative braking system to aid stopping. My estimation is the primary difference between the 24mpg highway and the 15mpg city is overcoming the inertia of the pilot's bulk and taking that stress off the gas motor would save a lot of fuel.

I have no real plans at this point and I'm not sure where to start in selecting components or pricing such a kit. Any comments or suggestions would be appreciated. (Yes, I could start a new thread with this-don't know how-but wanted to glom onto the 03 Pilot conversion thread)
 
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