2002 gem 4 seater lithium converstion

I have a 2002 gem four-seater and would like to convert it to lithium batteries. Does anyone have a step-by-step how to guide to help me with this process?

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@ScottyD has a front mount battery custom made specifically for 2002 Gem.

That’s awesome, do I need to change all the wiring? Also, are there batteries that will go under the rear seat too or just the front batteries? I’m a little over my head with this undertaking but I like learning so I’m taking it on. And honestly I’m just tired of my lead acid batteries dying all the time. I’ve had to replace batteries 3 times in the past 2 years because they all get drained from not being used for a month or two

Connects to existing B+ and B- wires. Front battery is all that’s needed.
Some modification to crossmember in front, but Scott will take you through it.
@AssyRequired has a similar one that he may put together for you.
front mount 22s

From what little i know, your wet batteries should not be doing that. They should last a few years as long as they are maintained. A couple of questions…

  1. What batteries are you using?
  2. Are you checking and filling as needed the battery water with distilled water?
  3. When not in use for a while are you charging your batteries up still regularly? I have a 2002 also. The charger will not trickle charge, so you have to unplug and replug it in to reset the charger. I have heard others get a heavy duty timer outlet so it will do that regularly. I plan on looking at that soon myself.

Hey @ScottyD , love the set up, I live in San Diego and I recently bought a lifted 2002 GEM, 72v 7.5hp motor with big wheels, and 6 12v deep cell batteries and having issue because I live on a hill, so I am Mr. cool guy going down the hill not so cool guy limping up the hill. I really love the cart and have spent a lot of time researching building my own Lifepo4 pack. P.S your shop is to clean,lol

Then you know better now?

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I would like to build, at minimum, a 72v 150 ah Lifepo4 Battery Pack for under $1800, and don’t mind using lower grade cells if needed. I initially thought the pack would have to be installed in the rear, but the front end might give better traction and balance. Thanks agin…

Most of the guys on here have moved on from the lifepo4 cells. They are great for solar backup storage but not great for the GEMs. Samsung SDI are popular and what you’re seeing in Scotty’s front install. He pieced those together with loose cells.

What hill we talking in SD? Sunset cliffs / pt loma, Soledad, del Cerro, helix? I chased this dragon with my 2000 in del Cerro. Lithium is a good start to get to solid hill climbing but you’re going to want to swap the gears from 10:1 to 12:1. Also, you’ll really want to get the controller out from under the dash… you’re going to be pulling a lot of amps esp being lifted so you’ll run into overheat issues on hot days.

After spending thousands trying to make a good car out of a crappy early model design, I threw in the towel and bought a 2016. I can rip up and down the del Cerro hill. Have driven it to pt loma and back no problem, and keeping up with traffic on 35-45mph roads.

As long as you know the early gems are complete modification money pits…and pressing forward anyway, my understanding is folks have figured out how to install a Samsung 22s SDI pack up front over the wheels with a JK BMS. It’s probably the most proven setup folks are running on here.

Post some pics of your ride!


Right on the Money, Del Cerro (I live on Ridge Manor Ave)… Wow, point Loma… I have had enough money-pits in the past, i just might have to rethink things, as I am not moving anytime soon…lol

Oh nice! You’re in my backyard. I’m over by Dailard. I have to go up and over the Del Cerro hill to get anywhere… KnB, Camino Rico to get anywhere in grantville / allied gardens (home depot, kids preschool, etc.). I’ll shoot you a PM.

I created some funny videos of me going up my hill in the GEM and posted them on youtube …Some are not that funny… Tombstone Dash - YouTube