Charger not shutting off

[chris1434]

2004 Club Car DS, 48V, PowerDrive 2 charger. I had a problem with the charger not turning on. I replaced the relay in the charger which fixed that problem. However, the charger won't shut off. I have read many posts on here about troubleshooting so I will try to give complete info.

When I plug the charger into the cart, it comes on for a few seconds, turns off and then turns back on. I have charged it for more than 16 hours and it does not shut off. The amperage drops down to around 5 and stays there for quite a while. Before unplugging it, the voltage was 59.7. About 7 hours after unplugging it, the pack voltage is 50.7. The cart runs fine and the batteries will run it for a long time. Also, when I unplugged it, the orange/yellow light that indicates an incomplete charge did NOT come on. I am in the process of trying to find another 48V charger in the neighborhood to test with but in the meantime was hoping to get some info / help on here. It seems the OBC is communicating with the charger to turn it on but I was wondering if there is a way to test if it is communicating to turn it off. Since the partial charge light doesn't come on, it seems the OBC believes it is fully charged (and it seems to be). What exactly does the OBC do to let the charger know to shut off? Does it send voltage down a certain wire or maybe remove voltage from a certain wire? If I can find another charger, I think it will be easy to know whether it's the cart or charger but in the meantime I was hoping to learn something and do some testing. I hope I have provided sufficient detail and appreciate any info and guidance. Thanks in advance.

[chris1434]

Another piece of info and a different question. With the cart charging and the battery pack above 59V, I checked voltage between the positive battery post and both sides of the fusible link. That voltage was only 55.4V. Should the voltage be the same as the battery pack? Maybe I am losing some voltage through the connections and not sending back the proper info to the charger?

[Fairtax4me]

Which fusible link? You mean the glass fuse on the grey wire? That will not read exact pack voltage.

The OBC on the cart may be failing, or you may have batteries that are not getting to the correct voltage for the OBC to recognize that they are full. Check the voltage of each battery while the charger is plugged in and charging, preferably after it has been running for a few hours and the amperage has dropped down into the 5-10a range. Each battery should be pretty close to the same voltage at that point. If you find that one is showing 9.2v while the others are at 9.6 or 9.8 or above, the lowest battery has an issue. Conversely, if one shows higher voltage than the others, most around 9.5v and one at 10v or higher, the higher battery may be the issue.
Remember this is While the charger is plugged in and charging.

Your rest pack voltage around 50.7 sounds normal but a little low, which could mean the pack just hasn't reached a full charge yet, or it could mean the pack has degraded enough that it is going south and that can be the reason the OBC is not stopping the charge. Hence the need to check battery voltages while the charger is running. If voltages on each battery are close to the same, then the pack is likely OK, and the OBC needs to be replaced, or change to a smart charger.

[chris1434]

Yes, that is the fusible link I was referring to. Thanks for letting me know that voltage doesn't match the pack voltage. It kept me from spending any time going down that rabbit hole.

I am happy to report that the charger is now shutting off. I don't know exactly what was going on but I will provide as much as I can about what transpired between the time it wasn't working until it started working again in hopes of helping anyone who has a similar issue.

The first time I noticed it not shutting off was when it was charging a full day after I had plugged it in. This was after replacing the charger relay. I first thought that maybe it just needed a longer charge because the batteries had not been charged in a few weeks while I was getting the relay fixed. I drove the cart a short while (a mile or so) and it was doing fine. I put it back on charge and noted the time. From my reading in this forum, I understood the charger is supposed to shut off after 16 hours. 18 hours later it was still charging. I unplugged it to do some more research. I plugged it in several more times over the course of a few days and it would never turn off. There was at least two more times where it charged for over 16 hours.

After your reply, I plugged it back in so I could check the voltages as you suggested. When I went out to the garage about 5 hours later, the charger was off. I drove the cart about 5 miles and plugged it back in. The charger charged the batteries and shut off again. Wanting to be sure, I drove it again about 1 mile and plugged it in. Once again, after a few hours the charger shut off.

The main thing that kept throwing me off was reading in several places that the charger will shut off after 16 hours. This was not the case. So, to avoid battery damage, I wouldn't just leave it connected. Since everything seems to be working now, apparently there are situations where the charger does not shut off at 16 hours. Perhaps it was doing some sort of maintenance charge on the batteries or something. I will keep an eye on it the next several times it charges, but for now, I am back in business. Thanks for your kind reply and suggestion.

[Papas 73Dart]

you should also make sure you don't have a battery that is internally shorting out . I had that happen once and it caused my charger plug to melt

[chris1434]

Thanks. I will do some further testing to be sure.