Charger Overcharging

[geoffarias]

About a month or so ago I did some battery maintenance on my Trojan 875 in my i60L I got Feb 2021 with Jan of 2021 batteries. Cart has approx 1500 miles on it. I turned cart to off and filled with distilled water (after a full charge) and disconnected all the batteries and cleaned terminals, cables and nuts with baking soda/water. I reconnected everything and took it for a ride.

I plugged cart back in (using same cable and outlet) and thought nothing of it. I woke up in morning to awful smell in garage (rotten egg) and batteries hotter than I have ever had them get. The lights on the charger and the charging port both were red. This was over 14 hours+ of charging.

I unplugged and measured voltage with a meter. Each battery read over 8.59 so seems like a full charge. Pack read 51.84V.

I thought it was odd but used cart again and plugged in. The issue kept happening intermittently. Each time I would go out after it being connected for 12 plus hours the pack while connected to charger would read 59V being applied to pack. (not sure if this is correct)

Contacted my dealer who agreed to swap charger out. The new charger which he ensured is programmed for the right batteries, continues to repeat this issue. The light never so much as even alludes to turning yellow or green. Last night i plugged in at 7PM and I woke up at 4AM with a sniff of rotten eggs (handler in garage) and rushed out to garage to unplug the cart.

Spoke to dealer this morning and he said try to leave plugged in outside of garage for 14-16 hours and see if that changes things with the extended time. I haven't tracked it exactly but most Ive charged due to the heat and smell has probably been between 12-14 hours.

I will be load testing the batteries tonight to further gather data in attempt to not simply spend 1k+ on batteries cause "they may be bad".

So the question - anyone else have this issue or know what it may be? Do I have sulfate buildup on batteries? What else could be causing this?

[ATrain]

There's a lot to unpack here, but first thought seems to be an issue with battery(ies) themselves, especially if you've already swapped the charger.

You could try driving the cart to an auto parts store if one is nearby and they usually have a little more sophisticated testing equipment.

[geoffarias]

Atrain - DM sent I was hoping you would respond