Just changed my battery today. I discover that there are different battery brand out there and it is better to get back Sony (same with the original one). Before that I bought a "camelion" battery, after changing, green I key keep flashing.
Yesterday went to TC, they check the battery voltage but found nothing wrong with its voltage but Green I key keep flashing. Changing to their battery then no problem. $10.70 for a tiny battery from TC is too ex. So decidede to get it from ABC shop and it cost only $2.