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John Deere Gator EV conversion to LiOn

1875 Views 21 Replies 7 Participants Last post by  pottscb
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Hey all,
I just bought a “for parts” heavy duty ATV for use on my place. It’s basically just a frame and bed, all the batteries were gone and most of the plastic, rubber, brakes, suspension, needs replacing, or so I thought. After getting it apart I found an aftermarket motor that is high torque (600A) and an aftermarket Curtis 600A motor controller so I can afford to throw a little money at the batteries (and I’ll have to as that motor will crush most 48V batteries, or at least the BMS of light duty batteries) I haven’t put the inrush amp load logger on it yet but I’d like to spec batteries that can handle 600A for a few seconds on startup (and 200A continuous) as I’ll be hauling/towing with it at low speed. It has a 24”x27”x12” battery compartment under the bed so I’ve got room. The battery compartment has openings on most sides and vent in front to let airflow through so cooling shouldn’t be a problem. I’m looking for enough capacity that I only have to charge 1xWk at most so probably 200Ah+. This limits my choices and makes them much more expensive, you can either have high amperage or long range relatively inexpensively, not both.

As I’m new to this, I started out looking
for the easiest PnP solution I could find, such as kilovault HLX+ 48V-300Ah but these run $6K MSR. Then I migrated to Nissan Leaf, but I’m having trouble finding them worth the money that aren’t at less than 50-70% capacity (which is when Nissan warranty replaces them). So now I’m at Tesla S modules which are the best bang for buck as far 48V-250Ah…but implementing them isn’t for the faint of heart. I’m not an engineer but I can read a schematic, the problem is, the current electrical system has been piggybacked/spiced for several small accessory switches and implementing the BMS and contactors complicate things and I can’t find a schematic for specifically what I want to do, which would be 2X 24V Tesla modules, fairly simple BMS (SimpBMS?), onboard charger with 12V shunt for lights, commercial sprayer, etc.

Anyone have feedback on this? Am I barking up the wrong tree with Tesla modules for a first time build? Anyone interested in me posting my build pics?

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Howdy & welcome

For what it sounds like your building
...& what you want to use it for

IMO you'll only need a ~2kWH (~50AH) to~4kWh (~100AH) battery pack
...& for a vehicle of that size, you'll never need or use 600A

Probably more like ~200A peak (for a few seconds)
...& maybe ~50A - ~100A continuous

I have a 48V 8kW PM motor on an old motorcycle
...& doing "the math" (8,000/48V=166.67A)

When riding around, I've seen it draw ~150A on hard accelerations
...& more like ~50A to ~100A when just cruising
...& hardly anything while coasting ;)
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