72V GEM blinking red indicator

I changed out 3 of my Trojan 1275’s this spring. When charging I get a blinking red indicator. I checked individual battery voltage during charge and one battery (a new one) is significantly higher at over 15V the other 5 batteries are charging at about 13.5V. Is this an indication I got a bad battery? Not sure how to proceed, any advice would be appreciated.

how many red blinks?

Seems to blink continuously …

I will look at it closer when I get home.

according to the manual - 1 blink - High Battery Voltage Detected
you battery balancing to equalize voltages?

That one battery which is charging at 15V seems suspect for being bad.

Here’s a thread on the Zivan charge indicator lights:

Looks like what is going on with mine. Agree 15V + battery is suspect. Just not sure how to check further. I guess I can put it on a normal charger by itself and see how it acts.

Were they balanced when new battery was added?
New one is full at 15v. Charge the others to match.

I charged them all individually a couple of days before I purchased the 3 new ones. Sounds like you recommend recharging them individually (balancing) and see if that fixes it. I agree, I will try that and get back with you all about results. I’m thinking I may have to end up replacing the other 3 older batteries.

After you fully charge a battery and move the chrger to the next battery, wait 2 hours and then measure the voltage of the freshly recharged battery(the one charged before the currently charging one ). Document the voltage and do this for all the batteries. Two hours after the last battery has been charged, measure all of the battery voltages and write those numbers next to the previous recording.

if flooded lead acid(Trojan 1275), they should all be in the 12.6V-13.0 range if in good shape.

Well I decided to drive it around the neighborhood and plug it in again. I did that and checked back in 24 hours and had a steady green light!! I drove it again this morning and plugged it in again, we will see how it behaves.

Hi, having the same issue, along with another one. Did it go back to normal for you?

Yes, it went back to normal, but occasionally I have to charge one of the older batteries separately.