Good morning, I would like to ask if the gem can work (motor only, and not the rest of the systems) if I replace the speed controller and the battery with 48 volts and leave the same 72volt motor.
Sure, but why?..
xxx…xxx
I have a new battery pack and motor. The original broken
You might need to define what you consider “work”.
I hope your expectations of both performance and range are not set very high.
It sounds like work to swap in the wrong direction and I think my favorite line from a recent infomercial might apply here - Avoid disappointment and future regret.
1 Like
thank you very much!
I think that I see your dilemma. Few parts available in your location.
In a previous post mentioned replacing batteries. What model year is your car?
Batteries in the front? It is rare to find a broken battery and motor.
Yet you ask about using the same motor at 48v.
We may be able to help given enough information. Much more to converting a car to 48v than you may think.imo
Listen to what is happening. I bought this car in 2007 with a damaged controller and I want to transfer the parts from an ezgo (engine, solenoid, wiring, controller) to this car. I do not want to make changes to the electrical circuit powered by the voltage converter which is 72 volts (for this reason I ask if this converter can work at 48 volts). Do you think this can be done?
The engine of the ezgo fits perfectly in the car’s gearbox.
Τhanks!
I think we get it, but in your post #1 you actually stated you were retaining the original 72v motor and only swapping the controller and battery.
I built your car in my head(another super power) and mentally installed the necessary harness to get the drive system operational. It was a tough call if I pull the harness out of my perfectly working (fictional) ezgo or use one from my scrapped out cart and gamble with tracking down possible wiring issues after the install.
I also drove the car around the neighborhood (in my head) and was not having much fun given it’s 48v golf cart performance. Realize that cutting the voltage in half doubles the amp requirements so performance and range are severely affected.
You might be perfectly happy with it tho if all you are doing is cruising around the property or campground.
You did not say what year your gem car was, so it is difficult to say how much of the original wiring you could use for the accessories. Both old and new generations have 72 and 12v tightly woven together in harness and on the pwb and PSDM. I suppose you could just hook 48 up to the dc converter and see what still works? Trying to diagnose any future electrical issues will be a nightmare. There would be a nest of unused wires running everywhere.
Really- all you need is lights, wiper, horn so it wouldn’t be difficult to just make a new harness. What converter do you have? Will it work with ~48v?
You also did not say what happened to your old motor and controller and what makes you think they are dead? Most of the time motors can be repaired. Repairs on a Controller are a yes/no gamble.
Batteries are a consumable.
Depending on the year and current condition of your car, you will also be lowering the resale value to a very low amount.
I tried to give a voltage of 12 volts to the connector of the inverter after consulting its manual and I have lights, horns, windshield wipers. I do not have a flash and the screen does not open from the steering wheel. The car was built in 2007 and I believe that with the 48 volt engine it will have the same performance as the 72 since the user manuals give the same final speed for both cars.
I hope the conversion succeeds.
No, need a 48v converter.
Even if you did manage to somehow get the screen to light up, it gets most of its useful data from the GE controller, since you are replacing it with some other controller you will not get speed or controller error data, direction selection(DH, DL, REV) and since you are not sticking with 72v the battery SOC is not going to work.
If you get real lucky, you might get a green arrow R/L turn indicator to work and maybe the headlight indicator. I don’t have the schematic in front of me at the moment.
What is going to be fun is since the display has lost communication with the controller much of it will be forever blinking (about once a second) in an effort to get your attention. You can tell people the destruct sequence has been activated and they need to get out quickly!!
You’re so preoccupied with whether or not you can, you didn’t stop to think if you should.
2 Likes
I’d agree… While it’s a interesting challenge to do the conversion, pay the $500 to have your controller rebuilt and call it a day.
Not only that, you’re most likely going back in performance. Why waste as the hours to have a car performing worse than you started with.
I’ve thrown stupid money into projects before… But I wouldn’t do this.
2 Likes