Ah, 2020 is a whole different ball game. It has all kinds of different crazy going on in those cars and I have not personally had hands-on with those systems yet.
My advice mainly go up to 2015 gem cars. Apologies for any confusion.
There may be others here that might know more about the Gen4 charging system.
I removed the original charger and batteries and installed Lithium. My charger just has the red and black.
Was anybody helping you with this?
What battery did you install?
What charger?
From what I understand this is not always a simple swap and go. The VMC and BMC are programmed via factory to expect a certain config. Anything outside the programming will make the VMC cranky. Expect to see a few error codes.
Thanks for the information. This is my first go at a GEM. I have done a number of Golf cart conversions. A friend asked me to try this. I put in a 105 ah/24 cell LifePo4 pack, JK BMS and 20ah 72v lithium charger from Summit Battery (not sure of the brand).
I did the battery swap first and then confirmed everything worked as it should. Then I swapped the charger and thats when I got the charging signal on the dash display. I wasn’t surprised as I figured there was some kind of charger lockout and knew the green and white wires were open.
I was very excited to read your comments on this post which explained the situation. You had recommend connecting the green to B+ with a switch so that you could reset the SOC meter. I thought I would go 1 step further and make that switch triggered by plugging in the charger and unplugging the charger. I’m hoping the 8 amp relay switch i have will fit that bill. The green wire will be connected to B+ when the charger is unplugged and will be disconnected when the charger is plugged in.
I am grateful for your advise and for being included in this group.
The first problem with your current plan is that the 2020 cars are a 48v based car.
I’m not sure anybody here has over volted the Gen4 cars THAT high.
How much of this did you get hooked up so far?
Realize that there is a HUGE difference in the design between a pre-2015 and a 2016 and up. It was a total drawing board wipe and start over from the ground up. You can think of it like when NASA went from the apollo to the space shuttle program.
Most of the stuff you read here applies to the cars that look like this:
Here is a photo of the cart I’m working on. It had 6 12v FLA batteries when I got it. Conversion went great. The relay on the green wire was perfect. It now works like it did before.
Well, See there. You don’t have a 2020 gem.
Up over the back window on driver side is the VIN sticker. Unless someone has been up to some creative shenanigans, you should use that for ID purposes.
How very odd. Quick search says that is a 2009. I would have guessed at least newer than a '12. I didn’t know they switched to a metal tagged VIN that early.
(Mine is also a 09 car and it does not have this).
Yes, DC motors up until about 2015 then Polaris went clean slate and redesigned the car. One of the changes was going to AC.
DC is fun, but has it’s limits. Mainly RPM. At least you are starting your education with a 2009 car. It has a real good base to build from, and still big potential for expanding. Being a little 2 seat car, the short wheel base by nature will make it a tritchy ride at high speeds.
Some of the real smart guys here have figured out the path to convert the legacy cars over to AC. That’s where the real fun begins.
