Fried battery ?

[EvanDavis]

In mid January we had a power cut in my area due to electrical works in the road going wrong.
Since then the USB ports on my PC would work at random. 1 day the ones on the front wouldn't word and 1 day the ones on the back wouldn't work. I found if I removed the CMOS battery and reset the BIOS to default everything would work fine for a few days but would fail again. Last week Friday I stuck a new battery in and everything has been fine since then.
Is it possible a power cut could have fried the battery ? Wierd I know.

 

[Peru Bob]

Probably not, as anything before the battery would be more susceptible to power surges.
It was probably just weak and the timing was coincidental.

How old was the battery?

 

[EvanDavis]

How old was the battery?

I got the PC in 2016 and it uses a Gigabyte H81M-S2H motherboard from which I can see was first released in 2014. Maybe just coincidental like you say.

 

[muckshifter]

Them batteries have a limited life. Failing within 5years is not uncommon.