HTC One: sudden battery discharge while on cable, how can I fix this?

[agoldenfiles]

HTC One: sudden battery discharge while on cable

My HTC One (7) was at 100% charge on the cable plugged into the wall overnight.

I picked it up (while still plugged in) to check an email and suddenly got the <20% notification , putting me in power saving mode. By the time I exited out of power saving mode, the battery showed just 5%. This all happened in less than 5 minutes.

What happened? Why would my battery discharge 95%, in minutes, and while plugged into the wall?

The phone is 2 years old. Time to get a new one, or is this fixable?
thanks

 

[Rukbat]

Re: HTC One: sudden battery discharge while on cable

Turn the phone off and charge it for about 8 hours. Turn it on and see what the power level is.

If it's 100%, keep using it and see if it happens again.

If it's down to 20% or less, the battery is probably shot (see Lithium Battery Dendrite links) and it can be replaced by any competent shop. The battery is in the $10 range if you buy it yourself, but if you have a shop do it (which is what I recommend), expect to pay around $50 for the job.