Hi. My 2012 e4 is my first GEM. I just noticed that if I put one probe of a DVM on the positive post of the battery bank and the other probe on the frame I get 61.5 volts. Wazzup wit dat? Is that normal? If not, what would I do to diagnose the problem?
The cart is a 2012. It only has 350 miles. It has no other accessories installed other than the factory original stuff: windshield wiper, heater/defroster, 12V port, orange flashing safety beacon on roof.
At about 300 miles the speed sensor on the end of the motor went bad, perhaps that was a related issue.
Hints?
TJ
Nominally it’s a 72 volt system so 61.5 volts seems a bit low. Are you sure you got a good ground for your testing? Any performance issues indicative of a low/weak battery condition? Can you measure the end-to-end voltage at the controller/12 volt converter rather than chassis ground? I’m personally not 100% convinced that measuring to chassis ground is valid on a GEM.
Did you measure each battery separately? Maybe one of the batteries is “shot”. I’d also check fluid levels if it’s a flooded lead acid system. After a couple of recharging cycles, my fully charged FLA batteries run about 13.1 - 13.2 volts each which should give you a total charge of 74 to 78 volts.
Al
Hey Al,
I should have been more specific. I have gel batteries and they are healthy. The whole pack shows about 79 volts. Each of the 6 batteries has just over 13 volts.
I’m not familiar with GEMs, but on Club Cars, Yamahas, and EZ-GOs the frame should NOT be grounded. Typically when there is a phantom voltage on the frame it is due to wet cell battery overflow that contacts the frame.
My suspicion with this GEM is that the emergency beacon is probably grounded to the frame hence the frame voltage is 2 batteries worth less than the whole pack.
I was hoping someone with GEM experience could guide me in the trouble shooting process.
Thanks,
TJ