Hello Zhelyo - Welcome to the Sony Forums

If the battery is definitely charging, it may just be a fault within the light itself which might not necessarily be any cause for concern. I have had a similar problem in the past with a laptop that was plugged into a hotel socket whilst a power surge caused a power cut. After that, it has charged without any problems.

Keep an eye on the battery and if you suddenly find that the charging stops working, you may need to get it checked out.

Thanks,

Simon