I have two batteries for my SGS2. One is the original battery and the other an after market one I bought on eBay. I have been using both for a few weeks without any problems until today. When I swapped out my after market battery for my Samsung one, I get what appears to be a battery temperature warning. Before the phone was switched on, the display alternates between the large battery icon in the centre of the screen with 5 white dots below it and a battery icon with a yellow triangle with an exclamation mark inside it with a thermometer icon overlaid. I have never seen this before but it appears to be a battery temperature warning. The battery was stone cold (or at least room temperature) and the phone was at normal operating temperature, which, in my case, is again barely above room temperature. Neither is even warm let alone hot. Turning on the phone with this flashing is difficult and the only reliable way I can do it is to boot into CWM and reboot. Has anyone else seen this? Does anyone have any idea what's wrong with it? BTW My after market battery continues to behave perfectly normally as it always has.