Charger not charging although it acts normal

As the title says, when I plug it up, the charger starts humming and the dash light turns orange. It will eventually turn green and shut off after a typical lengthy period of time. The batteries are simply not charging up. The % meter is steadily going down without ever being recharged, even though we charge it every day. We have had this car a few years and have never had any problems. The batteries are not gel, they are 3 years old, and have been fine until this charger mishap. Worth noting is that I did just add water to the batteries and open up the dash trying to chase down some wiring. I didn’t unplug or change anything (that I am aware of), I was simply just checking out the wiring. Not sure if I accidentally unplugged something by lifting the dash or not. Any help would be greatly appreciated. Thx

If you [carefully] put a voltmeter on the battery connections under the dash where the charger connections terminate, can you read a different voltage between when it’s plugged in and when it’s not? I would expect it to be something like 72 volts (or less) when unplugged (charger not providing any power) and 76 volts (or more) when it’s plugged in and should be charging (charger generating current). This test determines if in fact the charger was generating current rather than just relying on the LEDs.

I had a similar situation which I finally tracked down to a faulty on-board charger. It was going through the motions (humming, lights flashing on the charger unit) but the output of the charger in fact never produced any power to charge the batteries.

This was with a QuickCharge Corp. charger but the principle should be the same. I could also see if the charger was getting “warm” during use (it wasn’t) which further indicated a problem with the unit.


Thanks for the reply!! I tested like you said. It was 74.6 volts unplugged, and 77.0 volts plugged in. That was testing at the big cable connections on a silver box to the left of the smaller black box that I thought was the charger. (to the left when looking at it from the drivers seat) The smaller black box that says Zivan that I assumed was the charger only has a black plastic connecter plugged in to the top of it with small wires coming out. I didn’t test there.

The Zivan is the charger. The red and black wires coming out of it are the charging conductors. Voltage just befort the end of the charging cycle can be in the 80s or more depending on the type of batteries you have.

The facts that you are reading higher voltage with the charger running indicates the charger is working.

I woud suggest one or more of your batteries is bad. Let the charger go thru its cycle. Wait 3 hours and check battery voltage individually.

I’m assuming that every connection is bright, shiny, and tight.

Thanks! Will do and reply later

If the charger is working and it sounds as if it is, then the batteries aren’t holding a charge. I’d do what Old Houseboater suggests except I’d check the water levels first just to be certain they’re all up to snuff and [U]theoretically[/U] should be able to take a charge. By the way assuming you can get the caps off the cells and they are FLA I’d probably test using a hydrometer as well as a volt meter.

If the water levels are good and one of the batteries is reading low after charging, you have a difficult choice to make. Since the batteries are three years old, I personally would replace them all at the same time rather than just the one “bad” battery. Saves a lot of aggravation in the future IMO.

Thanks so much for the replies. Well, as it stands now, the batteries did charge on this last run. I am not sure if I am crazy or what. I will reply again later if there are any changes, but it looks like its working again and I didn’t change anything that I am aware of. They have definitely lost their stamina over the years, however this was an abrupt change this week in a car we drive almost daily. Not sure?? Thanks again.

Something is still wrong. I just unplugged it this morning and it was at 72%. I’m not sure if it charged up, and then charged down overnight. Or if it didn’t charge at all. I ran it last night down to about the 72% range before I stopped and plugged it in for the night. It was making the charging sound and the light was red (or orange cant remember) last night. Didn’t pay attention this morning if it was green or not, but I assume it was. I did remember that when I was adding water this last time, my arm came in contact with a positive terminal on a battery, and the frame at the same time and I got a little jolt. It was plugged in at the time, but not charging. I also felt a little buzz when I was checking tightness on my lugnuts. Should current be running through the frame like that? Thx

I’m not an expert on these, but it sounds like you have a wire shorting to ground somewhere. you shouldn’t be getting a buzz from checking the lug nuts unless your 5th or 6th beer! :smiley:

Ours get the tingle in them sometimes. Been doing that for years now. Also, make sure all of the battery cables are tight.


Thanks! All battery cables have been cleaned and tightened. I have also unplugged the radio and the +/- plug in the top of the charger trying to eliminate items that may be causing the draw and no luck yet. They hold charge fine when the main switch is off, but when it is on they run down in just a few hours.

Definitely sounds like something is drawing you down. A bad battery in your pack can do it. If you’ve eliminated that as a possibility, then its time to start tracking down the problem. Electrical problems can be very time consuming and frustrating. If you aren’t sure of how to go about it, it might pay to garner the help of someone who is. Just my 2 cents, I wish I was there to help you.

Thanks. There is only one dealer somewhat nearby that will work on these and I have considered taking it to them. Nervous about the potential cost though. If the main disconnect switch is off, wouldn’t a bad battery still run the pack down? If it would still have an affect I can pursue that more. However, I assumed that a single bad battery would run the pack down even with the switch off; therefore eliminating that as a possibility since the pack does not run down when the switch is off.

No, not necessarily. With the switch off, there isn’t a complete path from one battery to the next. The circuit isn’t complete, so while the one batt might still draw itself down, it won’t affect the others until the switch goes on.

Remove one fuse from the DC convertor, wait a day, and see if the draw continues. If not, put it back and try another. Eventually, you will remove a fuse and the draw will go away. Then you will know in which circuit to start looking.


Thanks for the help everyone. Just an update. It looks like the batteries were kind of bad, or maybe the charger is not 100%. However, I trickle charged each battery overnight… a couple times. It took awhile to do, but the cart is charging up to 100% and the batteries do not run down. My theory is that they were only charging up to 72% and when I was watching the volts drop (by the gauge and DVM) it was because I was checking too soon after charge (immediately). IDK, I could be wrong, but they are fixed now. Thanks for all the help.

! or more of your batteries is probably shot. Get a hydrometer and check after charging. the voltage reading may be up but specific gravity will probably be down, A sure sign of sulphation. I assume your battries are deep cycle flooded but NOT Trojan or equivalent Golf Cart batteries. 3 years isn’t bad for cheap batteries.