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Hello,
I’m new here and have a bunch of questions for the experts here. I have looked through the posts but I don’t see anything that helps me with my questions. I have a side by side that I bought originally to put a car engine and transmission in but I also want to put an Onan generator in it to power welders, lights, tools ETC….. The car engine won’t leave much room for a generator and that lead me to start thinking about an EV conversion.

I think my situation is somewhat unique being that I will have a generator onboard and I also don’t need much range at all. I will need as much power as possible not just because I’m a horsepower junkie but I will need to haul heavy weights and pull trailers with it. I have a 1 acre property that I work at and the longest distance I would drive it would be about 2 miles if I were to drive it to my house and back.

I think this would be a good fit for me but I need advice on what parts to use and maybe somebody to smack me in the back of the head when I try to put way too big of a motor in this thing. I have the ability to do this, I’m a welder, hobby machinist, built a few cars, written more than a few PLC programs, built more than a few PLC control centers and know my way around side by sides. It’s been a while on some things but I’m sure it will all come back to me.

The carcass I plan on using is a 2007 Motobravo 4x4 (similar to the Polaris Ranger) with the 500cc Cheri engine in it, 3:70 rear diff gear ratio, the transmission is missing. The vehicle weighs 900 without engine and trans-1,200 lbs with engine and trans. I have a hoard of Onan generators from 2,000 watt to 5500 watt that all run really good. I don’t plan on setting up the 4x4 on this unit at first to keep it kind of simple.

With the generator onboard should I try to us a 3 phase motor with a DC to 3 phase VFD ?
Should I go with a DC motor to keep it simple ?
Can somebody point me to a motor so I can start looking for a used one or see what I have?
There is a guy selling a complete 2013 Smart car drive train without batteries locally, is that the way to go ?

Thank you for any help you can provide
 

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I just found a guy selling a complete car locally pretty cheap. He says the car is complete and drivable but does have some quirks. He's asking $2,000 for it would this be the smart way to go ? This is the parts description he has in his ad :

- 45 ThunderSky Lithium Iron Phosphate (LiFePO4) LFP100AHA 100 Ah cells making 144 volts nominal. When full charged, battery voltage is almost 160V. (Original cells from conversion. 2-3 cells are starting to become weak).

- Batteries are in insulated boxes, with plexiglass covers to keep fingers out during shows.

- Each battery cell has a Mini BMS monitor board mounted to it. They are all working fine.

- Kelly Controller KDH14801E (no CAN). Controller has lighted fans and water plate for cooling.

- Advanced DC FB1-4001A 9" series DC motor

- Elcon 2000+ charger. Works on 240V or 120V interchangeably.

- Elcon DC-DC converter to keep 12V battery charged.

- MES DEA RM4 heater. Connected to main pack. Currently has an issue.

- Battery charge level drives the fuel gauge on the dash.

- Voltage and current meters have been added to the dash.

- Fuel gauge on the dash works. It is connected to a battery energy usage measurement.

- Thermistor in motor drives temp gauge on dash. Currently has an issue.

- Batteries are in insulated boxes with heaters in bottom. Heater circuit is blowing its fuse for unknown reason. Still drives OK in winter with insulated boxes, but heaters would help cold weather performance.

- Tachometer on the dash is driven correctly with hall effect sensor on motor shaft.

- The charging cable is a twist-lock connector under the gas flap (where else?) and cables for 120V, 240V, and J1772 are all included. The charger automatically detects the voltage.

- I have some documentation on the conversion, including manuals, wiring diagrams, and schematics, as well as some background and driving information for service techs.

- I also have documentation from the Idaho Department of Environmental Quality (DEQ) that it has been converted to electric and is exempt from emissions tests.
 

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Why make it an EV at all?

You're travelling all of 4 miles round trip.

Leave the engine in it.

If you're going to have a generator anyway, for that low of a range, I wouldn't waste time or expense on a battery at all. Maybe a couple starter batteries, but, that's all the range you'll ever need even without running the genny.

A VFD would work but you might have trouble monkeying with the speed settings at really low speeds. Especially without a tranny. Especially if you want to do towing.

I think the right solution is to do nothing, just use the factory gas engine, this isn't a problem that lends itself to an EV solution. You'll be putting up a ton of expense for benefits that you won't ever notice.
 

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Why make it an EV at all?

You're travelling all of 4 miles round trip.

Leave the engine in it.

If you're going to have a generator anyway, for that low of a range, I wouldn't waste time or expense on a battery at all. Maybe a couple starter batteries, but, that's all the range you'll ever need even without running the genny.

A VFD would work but you might have trouble monkeying with the speed settings at really low speeds. Especially without a tranny. Especially if you want to do towing.

I think the right solution is to do nothing, just use the factory gas engine, this isn't a problem that lends itself to an EV solution. You'll be putting up a ton of expense for benefits that you won't ever notice.
The side by side carcass that I'm planning to use doesn't have a transmission and I doubt the engine will ever run again which is the reason I bought it. I bought a few side by sides that were not running so I could build my own but they were easy fixes so I fixed them and now they run fine. I bought the carcass that I plan to use because there were too many parts missing to put it back together or fix it. I just want to build something that is my own and the EV sounds like just the ticket to me.
 

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I just want to build something that is my own and the EV sounds like just the ticket to me.
Ahh, okay. That's cool, you don't need to justify a project, if you want to, you want to. I just wanted to make sure before you put time and money into it that it wasn't the wrong solution for the job, which, it probably is.

The stuff in your ad... it's not a terrible price. All the little things add up. If you were set on doing it as cheap as possible you could save money by doing other stuff, but if you're comfortable paying $2k for something that's a complete solution with little hassle, I'd go with that.
 

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Ahh, okay. That's cool, you don't need to justify a project, if you want to, you want to. I just wanted to make sure before you put time and money into it that it wasn't the wrong solution for the job, which, it probably is.

The stuff in your ad... it's not a terrible price. All the little things add up. If you were set on doing it as cheap as possible you could save money by doing other stuff, but if you're comfortable paying $2k for something that's a complete solution with little hassle, I'd go with that.
You got me there, It is absolutely the wrong solution for the job. I have 3 other side by sides that I hardly use but isn't going to stop me from building another one. On the positive side it keeps me from smoking crack and out of the whorehouses ;)

I know that motor in the complete car is too big for what I plan to do with it which might not be a bad thing but will I be hurting anything by rarely using it's full potential ?

Does it shorten the batteries life if they're not run flat before they get charged ? or is it best to keep them fully charged all the time ?
 

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I know that motor in the complete car is too big for what I plan to do with it which might not be a bad thing but will I be hurting anything by rarely using it's full potential ?
Nope.

Does it shorten the batteries life if they're not run flat before they get charged ? or is it best to keep them fully charged all the time ?
Running them flat will kill them. Even just once.

The only batteries that used to sometimes benefit from full discharge were NiCads. All other chemistries (lead acid, lithiums) are harmed by it.

Lithium cells should be kept charged, but not at their upper extreme. For a 4.2v cell, it's often good to keep it around 4.0v or less.
 
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