Battery Not Charging 9500 .106 Problem

Hi
Weird problem with .106 on the 9500 has just occurred.
Put the phone on charge last night as it was down to 54%. Took it off charge this morning, still on 54%.
By the time I got to my car, was down to 52%, and was not charging in the car either.
Did a battery pull, and when it was back on, battery was showing as 28%.
The pull did the trick as it is now charging, but this is a little worrying - firstly the battery charge may be a re-occurring problem, secondly the charge status was wrong by all accounts until I did a battery pull.