48V Club Car - Stops Charging at 46.8V
 

Howdy BGW!

I recently acquired a 1996 Club Car DS (my first golf cart) and I'm trying to learn everything about it. I have some big plans for this cart, but my first priority is getting is cleaned up and running.

The batteries are a year older than I was expecting. They are Super Start GC8120 with a K6 date code (which should be either October or November of 2016). They were all pretty drained when I got the cart home - so much so that the charger wouldn't kick on. I hit each of them with my 12V charger at 2 amps for 30 minutes each to bring them up, as a pack, to 30+. That got the charger to fire, so I let it do its thing overnight. Now, the charger cuts off 46.8V for the entire pack.

Can someone help me understand why the charger is doing that? As I understand it, they should be hitting about 2.3V per cell, would would be 55.2V for the pack.

Thoughts? TIA.

Re: 48V Club Car - Stops Charging at 46.8V
 

What charger are you using? And if it is a Powerdrive it will cut off regardless of the voltage after 16 hours.

Re: 48V Club Car - Stops Charging at 46.8V
 

I have both a Powerdrive and a Powerdrive 2. They both cut off LONG before 16 hours.

Re: 48V Club Car - Stops Charging at 46.8V
 

Then if you are 100% sure your DVM is correct and you have verified it, your OBC is bad.

You can unplug the Pack Neg and place it in Reverse and depress the pedal for 30 seconds and then hook the cable back up and start another charge. If it still cuts off too soon, your OBC has failed. You can bypass it to test it.

Re: 48V Club Car - Stops Charging at 46.8V
 

I am using a cheap (free) voltmeter from Harbor Freight, so I'll be having a friend come over with a better one tonight to verify the accuracy.

If it verifies what my cheapo DMV is reading, how to I go about bypassing the OBC and testing from there? What should I be looking for?

Re: 48V Club Car - Stops Charging at 46.8V
 

You can bypass the OBC by running a 10g jumper wire from the back side of the charge receptacle (where the black 10g wire is that goes into the harness) and run it directly to the Main Pack Negative. Also take the grey sense wire coming off the same receptacle and land it to the same place. This will allow the charger to turn on and it will not turn off.... (You will have to do that once pack voltage reaches 61-61 volts)

Re: 48V Club Car - Stops Charging at 46.8V
 

Is 61V the proper level to which the entire pack should be charged?

Re: 48V Club Car - Stops Charging at 46.8V
 

If your OBC was working as it should, it would run between 61-63 (and as high as 65v) volts before shutting off.

By bypassing the OBC you will not be using the algorithm so therefor you will only be surface charging the batteries, This cannot be done long term as you will ruin them.

Re: 48V Club Car - Stops Charging at 46.8V
 

So, when/if I end up bypassing the OBC, I'll want to monitor closely the charge level and manually shut it down when it gets in the 61-63V range, correct?

Re: 48V Club Car - Stops Charging at 46.8V
 

This attachment will give you an idea of the expected battery charge voltages for the various stages of charging.