# What is the best motor for a van conversion?



## ickkii (Nov 6, 2013)

Hello, first time poster, 2+ year lurker.
As I am beginning to build a parts list for a planned sprinter conversion I find myself in need of a motor.
I had always thought the warp 13 to be the go to motor for the project but I'm starting to come down to earth a little more with the budget and was wondering if there are better motors for the job.

I estimate the project to be a modest 5-6 tons. I probably will avoid the interstate, however a max 60-70mph would be nice if possible.

Also given that this is my first build, what cooling is de facto currently?


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## major (Apr 4, 2008)

ickkii said:


> As I am beginning to build a parts list for a planned sprinter conversion I find myself in need of a motor.
> I had always thought the warp 13 to be the go to motor for the project but I'm starting to come down to earth a little more with the budget and was wondering if there are better motors for the job.
> 
> I estimate the project to be a modest 5-6 tons. I probably will avoid the interstate, however a max 60-70mph would be nice if possible.


I don't see 70 mph at 6 tons modest  That's huge. Offhand, I'd say you're looking at two of these. Siemens-1PV5135-WS28 or similar.


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## ickkii (Nov 6, 2013)

major said:


> I don't see 70 mph at 6 tons modest  That's huge. Offhand, I'd say you're looking at two of these. Siemens-1PV5135-WS28 or similar.


Yikes that voltage is a little much
Maybe drop it to 5 tons and 55mph max?

Not really sure what the bare sprinter weighs, but there won't be too much in it aside from batteries.


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## Ivansgarage (Sep 3, 2011)

Here read about this truck (motor and controller)

http://ivanbennett.com/forum/index.php?topic=16.0



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## zeva (Nov 4, 2013)

Ouch, that Siemens motor is almost twice the price of a Warp 13.. and a big enough inverter is likely to cost as much again! Despite the protestations of AC fanboys, AC gear is still much more expensive than DC.. (*puts flame suit on*  )

The Warp 13 would be a decent option for a vehicle that big, but if you're looking for "bang for buck" perhaps dual Motenergy ME1002s at about $1400ea: http://www.motenergy.com/me1002.html

That'd give 50kW continuous, which should be enough to drive a 5-ton truck at 60mph. Motors wired in parallel with a 1000A controller (water-cooled Zilla or Soliton for sufficient continuous power) and a ~150V battery would give decent performance. Motors in series with a 1000A controller and 300V pack would be very spritely, but 300V is a fair bit more dangerous to work with so you have to know what you're doing!

Air cooling is most common for DC and industrial AC motors, water cooling for the higher end AC. Water definitely allows for higher power density, but usually comes at a premium.

I guess you've figured out by now that the cost of doing a conversion goes up roughly in proportion to vehicle size and performance..


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## ickkii (Nov 6, 2013)

zeva said:


> Ouch, that Siemens motor is almost twice the price of a Warp 13.. and a big enough inverter is likely to cost as much again! Despite the protestations of AC fanboys, AC gear is still much more expensive than DC.. (*puts flame suit on*  )
> 
> The Warp 13 would be a decent option for a vehicle that big, but if you're looking for "bang for buck" perhaps dual Motenergy ME1002s at about $1400ea: http://www.motenergy.com/me1002.html
> 
> ...


I have no preference to ac or dc, I'd love an AC for regen breaking (plus Nikola Tesla is one of my favorite scientists) - but for the cost of a DC motor I can live a happy camper. I haven't done very much research on dual engine setups, I know they are a little rougher to calibrate and that is about it. 

For air cooling the motor where does the air intake usually go?

The bulk of the project is mainly in a 75kW hybrid supercapacitor-LiFePO4 bank so I doubt 1000a will be a problem with the capacitors in mind. I think the drawback to dual motors would be that I am putting the bank behind the cab, in between the axles for decent balance and to conserve space up front for a small diesel/biodiesel generator. The generator could go, but since I'd like to do some camping it's a very convenient method of charging a planned 10kW auxilary bank for overnight HVAC. 
I'm still accumulating funds so the cheaper the better, although given the scale of the battery bank an expensive engine and controller can be probably offset by waiting a few years for graphene supercapacitors.


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## zeva (Nov 4, 2013)

IMHO the tricky part about dual motors tends to be mechanical, i.e coupling them together, fitting them in the vehicle (especially difficult with transaxle vehicles). Electrically, Series DC motors play very well together off a single motor controller.

For DC motors the air intake is usually the commutator end. They have an internal centrifugal fan at the opposite end blowing air out, so it gets sucked in at the comm end and pulled past the windings.

By the way, it is a common misconception that a 1000A motor controller needs batteries that can deliver 1000A to be of any use. Controllers act like a buck converter, able to step up amps when they step down voltage. So for the bottom half of the rev range, the controller can deliver 1000A to the motor without pulling more than 500A from the batteries. (Bit of a simplification but you get the idea!)


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## Caps18 (Jun 8, 2008)

Look up Jack Rickard's Escalade conversion. Send him an e-mail asking about that setup vs the dual AC-35's or AC-75 motors.

I don't know what the top end performance would be when it comes to weight and speed, but I think it can be done. It might be kind of tricky for the first build though.


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## ickkii (Nov 6, 2013)

Caps18 said:


> Look up Jack Rickard's Escalade conversion. Send him an e-mail asking about that setup vs the dual AC-35's or AC-75 motors.
> 
> I don't know what the top end performance would be when it comes to weight and speed, but I think it can be done. It might be kind of tricky for the first build though.


I looked at his blog just now, I find his project reassuring. For one he's doing a hybrid capacitor setup. I initially had intended to do this with lead-acid and a maxwell capacitor bank however later on I decided that since this will be my only vehicle for a while - that I would go with LiFePO4. I had still intended to have a capactor bank for current load balancing (he describes it as a 'buffer') with the LiFePO4 bank, but after finding hybrid-cells with rated at around 25C I had found my candidate. I still have elected to have a 12v capacitor bank running the headlights, power steering, breaking, backup camera, and other miscellaneous items involving the vehicle. The caps will be charged from the main vehicle bank and the 12v 10kW auxilary bank which handles hvac, radio and interior non-critical items.

He mentions dual netgain 9 motors, I'm not sure why he chose those other than to cut costs. There also were some problems with the transmission not getting ECU signals from the ICE, don't think I will really have the same issues coming from an embedded systems background.

I'm removing everything from the van that can be removed. I'm hoping the body is under 3000 lbs so I can max out at around ~5000 I think. Ideally I'd use a lighter body but at that point I'd almost be building from scratch. If I get lucky I might not need the same power he has on his 7 ton escalade, so maybe dual netgain 9s may work. I still feel the warp 13 may be the motor for the project.

I don't have any up to date circuits made, just this doodle I made to kind of lay a few things out.


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## ickkii (Nov 6, 2013)

zeva said:


> IMHO the tricky part about dual motors tends to be mechanical, i.e coupling them together, fitting them in the vehicle (especially difficult with transaxle vehicles). Electrically, Series DC motors play very well together off a single motor controller.
> 
> For DC motors the air intake is usually the commutator end. They have an internal centrifugal fan at the opposite end blowing air out, so it gets sucked in at the comm end and pulled past the windings.
> 
> By the way, it is a common misconception that a 1000A motor controller needs batteries that can deliver 1000A to be of any use. Controllers act like a buck converter, able to step up amps when they step down voltage. So for the bottom half of the rev range, the controller can deliver 1000A to the motor without pulling more than 500A from the batteries. (Bit of a simplification but you get the idea!)


Interesting fact about the motor controller! I think I'll take one of my arduinos and get a few tiny motors to do a few small scale conceptual builds with series motors. 
I am familiar with Solar MPPT controllers that do something similar to what you are mentioning.


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