Batteries have different voltage reading

[Anonymous user]

Two of my Back-UPS RS 1300 were failing. After removing the batteries and the bridge connector, I used a voltmeter to read the voltage of each battery.

In each set, one battery read 8-8.5 V and one read 12.5-13 V. I can confidently say that the 2 batteries with low reading are bad (one of them is bloated with a cracked case). But can the other 2 batteries be considered good and can they be used together in one of the UPS units?

[Brad_C]

The honest answer is "probably not".

You could pull them out, charge them up independently and perform a load test on them (use a 55W car headlamp bulb), but if the adjacent batteries are dead there's very little chance the other batteries have any valuable life left in them.

[Anonymous user · Accepted solution]

Thanks. I'll try that. I don't expect much more from those batteries but would be fine with another 6 months to a year.