Battery light on a 1996 48v (sn-A9649) is staying on

UGA_FAN

The battery light on my 1996 48v cart is staying on. It has been sitting for 4-5 years. I decided to buy new batteries and get it going again. I replaced 6 dead Trojans with 6 new Duracells. The charger wouldn't charge. I tore the charger apart and found that it had a bad relay. $10 later, I have a working charger. I fully charged the batteries, but the battery light next to the volt meter stays on. It stays on regardless of the position of the F/N/R lever or the On/Off switch. It will go off when I drive the cart and will stay off for a few minutes after i park it but always comes back on. The previous owner did put an Alltrax NPX4834 controller on the cart but did not change out the solenoid or the F&R switch. While trying to get the cart going again, I did find that the fuse in the yellow boot below the charger plug was blown. Lastly, after letting the charger go through a full charging cycle and letting the cart sit for a day, I checked to voltage of the batteries individually and across the pack. The batteries all read ~7.4v individually and 48.8v across the pack; which seemed odd to me. Alright BGW geniuses, what is going on with my cart?

BGW

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mrgolf

Are your batteries 8 volt? Is the charger 48 volt?

UGA_FAN

Yes to both. New batteries. Old charger.

Sergio

Fully charged 8v batteries should be about 8.5v or 51v for the pack.

Your posted voltages don't add up correctly either, if your voltmeter has scale settings, use the 20v DC scale to measure individual batteries so you get 2 decimal places of precision.

Ideally you would want to get a pack measurement right before the charger turns OFF to make sure the voltage is around 60v and then measure each battery again after 12 hour of rest.

UGA_FAN

Gotcha, I had the meter on the 200v setting for the individual readings. I did take a reading across the pack while the charger was charging. The reading was ~55v. I am not sure how long the charger ran after I got that reading. At the time it was charging at 10a.

mrgolf

Oh BTW the reason you battery light is staying on is the batteries are low, it is working correctly.

UGA_FAN

Forgive me. I am new to this. I bought new batteries. Replaced the inline fuse below the charging cable input. Replaced the relay in the charger. Charged the cart overnight on Monday. The charger was off (finished) on Tuesday morning. I left the charging plug connected. Tuesday night, because the battery light wasn't on when I got in the cart, I thought my "issues" we gone. I used the cart for 5 min to go out to the mailbox. 5 minutes after I parked it, the light came back on. That is when I took the readings across the pack. I reconnected the charger. When the charger did not come on after 10-15 seconds, I disconnected the charging cable and the negative battery cable going to the OBC because I didn't want anything to fry while I was trying to figure out if something was wrong. Oh, also, the voltage meter next to the battery light reads as "full" charge. Should I just plug the charger back in and stop sweating the light?

Sergio

At 48.8v your batteries are only about 55% charged, that is why the "Warning Light" is ON.

Since You are new to Club Cars with OBC, make sure there is a single cable on the pack negative battery post and that the cable goes through the hole in the OBC.

There should be no other cables or wires on the pack negative battery post.

Reset the OBC so it can run another battery health charge profile.

All You need to do is disconnect the negative battery cable for more than 10 minutes for the OBC volatile memory to be reset.

Connect the battery cable back and plug the charger, make sure the ammeter goes all the way to maximum on the beginning of the charge cycle.

The current on the charger meter will be between 3 and 4 amps at the end of the cycle, take a few pack readings before the charger is OFF to make sure the voltage is 60v or higher.

You should also get a digital voltmeter to replace the "fuel gauge" type meter you have since those are notoriously inaccurate.

UGA_FAN

Got home. Did an OBC reset. Plugged in the charger and....nothing. No click from the relay, nothing. I waited a minute or two then went go inside to stew over it. Came back out 10 minutes later and it’s charging. Right now I am getting 55.2v across the pack and the charger is charging at 9 amps. I am pretty sure the batteries themselves are making a bubbling noise. Hope that’s normal. I’ll get a close eye on it and report back with the max volts near the end of the charging cycle. The “State of Charge” meter on the dash (pic below) kinda gives me the heeby-jeebies too.

Attached Images

A248D03A-9FC7-40AC-8358-E80A3AB139CA.jpg (110.6 KB, 0 views)

UGA_FAN

I pulled the dash back and measured the volts across the pins on the back of the “Fuel gauge” meter. Got exactly the same thing as the measurement across the pack, 55.4v