2013 RXV battery charge issue

[Mccoy38]

Hello all. Looking for some help as I am stumped.

2013 RXV. Four New US 12v in June 2018. Cart has been working well until last week but had to get pushed home after 18 holes. Never had this issue since I replaced batteries 5 months ago and why I replaced them. QE Charger is charging but for the life of me I can’t figure out why but my third battery in the pack is not taking the charge. I’m getting 15.5v on each battery while charging , except the third battery from the main positive cable, the battery under driver. It’s only showing 12.7v with charger on and others get up to 15.5 or within .2 of each other.

So I tested SG on low battery and all cells were all very low. Replaced this one with new battery under warranty and moved new battery to the middle and the middle battery to the 3rd location I was having issues with. I charged pack and then charged new battery with 12v car charger overnight (as it was lower than others before I charged pack. This helped after one charge but was still 45% SOC after 18 holes which is low.

Today I drove 2 miles to the club and it dropped to 79% SOC. Rode with someone else for 18 and drove it home another 2 miles and it was at 72% SOC.

Put on my charger and it did the normal long green light chargw up to 60v. But now again the 3rd battery is not charging like the others. I bought new cables when I replaced the batteries 5 months ago. So I changed them back to the old ones and still getting same voltage. This is not making sense to me, I am getting 60+ volts across pack on above 80% charge. Why is this battery location getting skipped? I also just charged overnight on 12v charger and will not come up.

So , i plugged into my neighbors same QE charger for RXV , however his sharts charging then kicks off around 55v and a few seconds later kicks back on and keeps doing this but no red light flashes. So I quit using it so I didn’t mess his up.

I am stumped. Cart runs strong @20 mph but range is terrible. My voltage drop up hills is going down to like 42% and seems it did not use to go that low. I have the dvm that shows %,hrs, and v.

I Will replace all batteries if needed but seems something else is causing this but doesn’t make any sense to me .... other than my neighbors charger starting and stopping.

Hope this makes sense. Anyone ran into this or know where I should start? They will not replace batteries if they are not bad and this one was taking and holding charge when it was 2nd in the pack. Everything is following this third battery location.

[rngilliland]

Do you have any accessories hooked to the third battery. A friend of mine had a usb port hooked to one battery and it killed that battery after about six months.

[rngilliland]

Not sure if you are getting the SOC from the meter off ebay that plugs into the harness. I have that meter on my cart and the voltage is accurate compared to my multi meter. But the SOC it shows is always low compared to the SOC charts I have seen on this site.

[cgtech]

I'm betting the lights are hooked to that battery, even Ezgo did that for a while. Manually charge that battery with a 12v charger, and disconnect the accessories that are hooked to it until you get a DC converter to power your lights and 12v stuff (disconnect them to encourage you to actually fix the problem, not just going to cause more trouble with a bandaid).

[Mccoy38]

****. That battery does have lights and horn on it. But are never turned on. So figured they would not draw anything. I have 48/12v reducer so will move those on it too.

I got that 3rd battery up to full charge overnight on 12v Charger but don’t want to do that every time I charge it. Still feel something isn’t right bc when I test each battery while on charge it’s at like 12.9 and others are 14-15.5 and even 16v at end of charge. but will try it. I am at 12.8 on all of them now but it’s 40 deg here and hard to tell true range.

Thanks for input and will shoot back what I find.