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John Deere Gator EV conversion to LiOn

1874 Views 21 Replies 7 Participants Last post by  pottscb
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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Wow, I didn't know JD made electrics. Is that thing 2WD or 4WD ?

I think Tesla modules are the wrong tool for this job - they're 6S, so you get a 12S with two in series. Lead-Acids would be at 45.6V near full discharge, but 12S NCA would be 36V or so... Thus 14S is a better configuration for converting former Lead-Acid 48V systems, and even 16S in some cases.
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You do understand that lead acid battery chemistry only allows 40% of its capacity to be used before its performance starts to drop off? I have an inrush current meter on an aftermarket high torque motor and have never exceeded 200 amps for 1 sec while flooring it…under heavy load I’ll prob. take it easy (or maybe add another battery so I don’t have to). The specs are in the link above…210Amps-10 sec; 250Amps-5 sec. ~350A-immediate shutoff…here.
You're mixing different contexts. @brian_ made a relevant comment. You seem to have the data to suggest his concern is not applicable in this case, but you also don't seem to understand the quirks of the "lead acid battery chemistry."
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