11 Precedent OBC and PowerDrive 3 issues

LJ12530

Working on a friend's cart. He brought it down because the lights were not working, and a battery hold down was hanging down below the cart. I opened it up and there was quite a bit of battery corrosion. That was the cause of the battery hold down problem. It had corroded completely through. I also noted that a black wire connector just to the left of the last 8V battery in the string. I put new connectors on the black wire and as expected the lights now all work. Also replaced both hold downs.

Now it gets interesting. I also noted that the bottom right corner of the OBC was sticking out from the aluminum structure about a half inch or so due to the growth of corrosion. I pulled the corner of the OBC away from the aluminum structure and scraped off the corrosion. I then pushed it back and put on a bit of adhesive to keep it in place. So far so good. Lights work, battery held down. corrosion cleaned up pretty well and the OBC is flush with the aluminum structure. I brought the cart back in and plugged it into my PowerDrive3 charger. Relay picked up, but the ammeter pegged pretty hard left. I figured there was a problem so I had him take his cart home and plug it into his charger. Same results. He brought the cart back and I did the OBC trouble shooting procedure in the manual. I did procedure 19 (onboard computer gray wire) step 1, and got 0 volts indicating the OBC needs replaced. Today I figured I'd do the charger gray wire into OBC bypass procedure. I did that and nothing happened. I then tried the charger relay bypass procedure and nothing. At that point I figured out my charger wasn't working either. So here I am, his OBC has apparently failed and my charger appears to have failed.

Could a bad OBC cause my charger to fail ?

The only taps on the batteries are a red one on 1+, and a blue one on 4 -. Any chance that the black wire repair that I did to restore the lighting system is related to any of this?

Any suggestions on a simple fix to try on the Charger?

Any other thoughts or suggestions?

I do have continuity from the gray wire on the power plug and the terminal going in the OBC.

Lengthy post, but I can't help it......retired engineer!

BGW

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Sergio

So neither one of the chargers work in your cart either?
Take a voltage reading between the + and - at the charger socket. If you are not getting a reading, check the continuity on the red wire to the pack positive.
If that is good than the SCR in the OBC is bad, but I don't think it would damage the charger.

LJ12530

Right now I have programmable power supplies individually charging 2 batteries. I'm running them at 10.5 V, and a 5 amp limit. I could go higher, but I don't want to burn out the power supplies. I'll get 2 of them charged and then run the procedures you listed. It appears that the OBC is a sealed unit so I gather that any internal failure requires an OBC replacement. I still can't figure out what caused it to fail...assuming it did. I worked on everything with the key off and R/T switch to T.

LJ12530

Good continuity between the red terminal on the receptacle and the + battery pack. Every test I have run says the OBC is bad. Fortunately it is under warranty.

Now.......I have to figure out what is wrong with my PowerDrive 3 charger.

thx for the help

Sergio

I looked at the powerdrive 3 wiring diagram and the ammeter going to the left would be consistent with not having a connection between the negative wire from the charger socket and the pack negative. That also explains why by-passing the relay in the charger would not have done anything either.
Since the negative connection goes thru the SCR in the OBC, if there is no corrosion anywhere in that path from socket to OBC and OBC to controller, then the OBC is still the suspect.
Something must have happened though between the time the cart left your house and came back, if the OBC sense wire (gray) was bad as you tested, the relay would have never come on as it did the first time.
Good luck with the charger....

LJ12530

So............I'm tearing down and checking the charger because

Oh, well it's a learning experience. My repair philosophy seems to be .. if it's not broken, break it..!

LJ12530

If you are having a problem with your '11 Precedent equipped with 8 V Crown batteries you might be interested in the recent court ruling between Club Car and Crown.

For the purposes of the lawsuit Club Car acknowledged a design problem with the OBC/battery system design.

I spoke with a person familiar with the issue and was told that there definitely was a problem ( I think it was fixed by an OBC software fix, not sure ). I was also told that if you have those batteries with the original OBC you can expect a shortened battery pack life.

I worked on a cart for a friend and measured the specific gravities of each cell. They were all over the place. The OBC had also failed. The OBC was replaced under warranty and the dealer installed a different type of battery cap. Not sure why the latter would have any effect unless it was more of an electrolyte spillage issue......the cart was very, very corroded as witnessed by the battery pack hold down being corroded to the point of failure.

Attached Files

USCOURTS-ohnd-3_12-cv-02158-0.pdf (162.7 KB, 0 views)