I've been having an issue with my Lumia 640XL battery which started on Wednesday. If I plug my phone's charger the battery icon will display that the phone is being charged but the battery percentage will subsequently drop while the phone is being charge. At first I thought it was a battery issue then I got a new battery this morning but have being experiencing the same issue. I really need info if this is a hardware issue i.e. The charging port is bad so it wont supply the battery with the regular charge or if it could be an issue with the OS being on fast Insider preview.