HELP!! Charger drains battery after headlight instal

[myrick-2012]

Hey y’all,

New to the forum and first post here. Sorry for the long post... I just recently purchased a 2004 CC Precedent 48V (4x12V) and added the Madjax Ultimate Light Kit Plus. The kit looked great and claimed to be straight forward to install. The instructions were not relevant to what was in the kit (no instructions for bucket harness, one sentence instruction for reducer, incorrect labeling, etc). After watching MANY YouTube videos, I felt like I pieced enough information together get the job done.

Once the install was complete, there were a few outstanding questions I had. While the lights, signals, and horn worked, the gray bullet connector on the factory harness was not there and I was unsure if the negative lead on the reducer was connected to the right spot.

2 days go by and I install my high speed magnet. When I go to plug the cart up to ensure a full charge before my speed test, it was only reading half charge. After an hour, the batteries were boiling and the charger read a quarter charge. After I saw this, I just disconnected the main pos and neg leads to hopefully prevent any further damage.

Any ideas on what’s causing this...? TIA!

[Htownblue]

You likely installed a kit for 2008.5 and up year models for starters.

[myrick-2012]

Originally Posted by Htownblue

You likely installed a kit for 2008.5 and up year models for starters.

I will paste the link below for what I ordered.. Clearly shows 2004 and up. The part number also matches what was on the box.

https://www.golfcartking.com/madjax-...years-2004-up/

[KACinPA]

Originally Posted by myrick-2012

After an hour, the batteries were boiling and the charger read a quarter charge. After I saw this, I just disconnected the main pos and neg leads to hopefully prevent any further damage.

What do you mean by "the charger read a quarter charge?"

[myrick-2012]

Originally Posted by KACinPA

What do you mean by "the charger read a quarter charge?"

The amp meter on the charger reeds 0 to 20 in 5 amp increments. So when I plugged it in, the meter read 10 amps, then an hour later I checked again and it was down to 5 amps


Sent from my iPhone using Tapatalk

[Fairtax4me]

Originally Posted by KACinPA

What do you mean by "the charger read a quarter charge?"

What he said. ^^^

The guage on the charger is an ammeter. It shows current flow, not charge amount. 1/4 guage, would be about 5 amps depending on the charger. Which is normal for a charge sequence that is in the final phase of charging.

You had the batteries disconnected doing the install for the lights which would have reset the OBC on the cart. If it had a full charge before, the OBC is now doing an evaluation charge on the pack to determine how it needs to charge. It's almost the same as an equalization charge, which will keep the pack charging at a slightly higher then normal rate to bring the voltage of each battery cell up to match each other. This will cause some bubbling of the water in the batteries, and is totally normal. It does not harm the pack.

If you have a bar graph charge meter on the cart you should ditch that and get a digital Voltmeter to put in its place. Follow a State of charge chart and use the actual pack voltage to determine charge level rather than relying on that unreliable bar meter.


That light kit looks like it uses a 4 wire voltage reducer. Those 4 wire reducers stay On All the time when they're hooked up, and can cause a drain on your pack depending on what else you have hooked up to it. They can also cause other problems on Precedent carts if you don't have it properly connected. The Negative side of the reducer has to be connected to the B- terminal of the controller.
If it's not grounded to the B- terminal at the controller you can have 2 problems. You can have a voltage backfeed in the harness which will keep the cart controller powered On all the time.
You will be using energy from the battery pack that the OBC in the cart can not measure. This will throw off the amount of energy that the OBC calculates to recharge the pack, and it will be constantly undercharged. Eventually this will cause damage to the pack that is not reversible.

The reducer ground Must be on the B- on the controller. And if that's a 4 wire reducer it will always draw current from the pack. There is a way to fix that with a relay.

[HaulnA$$]

Originally Posted by myrick-2012

The amp meter on the charger reeds 0 to 20 in 5 amp increments. So when I plugged it in, the meter read 10 amps, then an hour later I checked again and it was down to 5 amps


Sent from my iPhone using Tapatalk

That’s normal. The charger will charge at high current constant during the “bulk” phase then taper down the current and raise the voltage during the “absorption “ phase, HTH