I've used Lumix cameras for many years. Settings like time, date etc. are supported while you charge the main battery by a small battery (capacitor) for a small time. True of many electronic devices that require the removal of the main battery to recharge. However, most of my photography is wildlife, and as an RSPB volunteer I haven't been able to get onto reserves. My main battery was flat for too long and the capacitor charge went with it, So, the question is: did you leave your main battery flat for a long period. If so you will need to reset your time/date. Best to recharge your battery before ir is fully flat. There is to my knowledge no own board recharge on Lumix cameras at he moment