48V Charger Failure - I think

[Sergio]

That does not bypass the entire OBC, only the relay activation.

You need to run a 10ga wire from receptacle negative to pack negative in order to bypass the OBC current control circuit.

[fllint54]

Originally Posted by Sergio

That does not bypass the entire OBC, only the relay activation.

You need to run a 10ga wire from receptacle negative to pack negative in order to bypass the OBC current control circuit.

Sergio, thanks (!), I'll make that change in the morning and report back. I'm hoping that solves the easier half of my cart woes.

[TahoeDawgZ71]

Sergio is 100% correct. If the ammeter registers after you bypass the charging circuit of the OBC you'll know for sure that it's an OBC problem. With your symptoms, it usually is an OBC problem.

[fllint54]

Well, I'm amazed, and would have lost money on a bet that this would make a difference, but it truly did. I connected a jumper cable between B- at the receptacle and B- at the pack and the charger started singing. Why this puzzles me is because the B- receptacle lead already connects directly to the B- pack wire at controller terminal N, thereby making a clear connection to pack. I don't understand how the OBC can disrupt this current path, unless it just sucks the current away where the B- cable passes thru the hole in the OBC, but somehow it does.

Now that this charger is shown healthy, I still have to figure out how to get by without the OBC and also avoid overcharging. Is there a way to "smarten" the charger so that it operates in lieu of the OBC? Hard to think about buying a DPI charger when this one functions, and would rather not spend money on an OBC that is likely to fail again, if there's a better way. A thousand thanks to you experts for sharing your knowledge and experience!

[jjance]

I've heard of people adding a external timer. It would have to be a heavy duty one. Enough to handle a 1000 watts.

[Sergio]

Make sure the fuse on the red wire from solenoid to OBC is ok.

Make sure the negative wire from OBC to Controller N is ok.

if those are OK, then the OBC is bad.

Just to clarify, the negative wire from the charger receptacle goes straight into the OBC, then a different negative wire goes to controller N.

There is a device inside the OBC (an SCR) that controls the charger current.

Your best bet may be to get a "smart" battery charger like a DPI accusense.

The club car OEM charger is just a power supply, the actual charging control is performed by the OBC.

If You run the OEM charger with the OBC by-passed, make sure You unplug the charger once pack voltage gets up to +60v.

[fllint54]

Sergio, thanks for the clarification on B- routing. That now makes sense. I'm puzzled about the final pack voltage recommendation. I'm seeing pack voltage right now of 59.9V, yet the hygrometer readings remain below 1.2, indicating a good ways to go yet.

The DPI is probably where I'll go, unless there's a module I could add to the OEM charger that will allow it to work like the DPI. Hate to discard a working device if it can be made smarter.

[jjance]

BTW can you drive it yet. Wondering if the two problems were related.

[Sergio]

That was not a final pack voltage, but a safe number to unplug the charger.

Since the OBC is by-passed, the charger will not stop charging and it could gas the batteries pretty quickly after 60v.

If you are watching and measuring the batteries specific gravity, You could let it stay on the charger.

Make sure You adjust for temperature if your hydrometer is not the temperature compensating type.

Perhaps you can try to sell Your old charger to offset the cost of the new charger.

[fllint54]

Thanks for all the help! I've taken the charger offline now that SG has reached a desired >1.25 on all cells. I'm very close to standard temp (77F) here, so
temperature correction (today) not an issue. When I took the charger off I was seeing pack voltage of 62.5 which immediately dropped to 54.5 when I disconnected the charger. My new concern is that the batteries do not charge at the same rate, even though they're same age (1 month), same lot, and all new cables. Battery #6 reaches 100% (and gasses) long before the others reach 75%. Yes, DPI seems the way to go, as I'll be getting rid of the OBC. To Jjance, no, even with full battery power I'm back to solving the bigger issue of why the "no run" condition (on the other thread).