I had a bit of a scare today with my brand new Vaporesso. I installed a Tesiyi 40A battery and everything was great. Then, the LCD display on the device started acting funny... Even when I switched it off. What was worse was that the device started heating up! Returned it to the shop and after replacing the battery with a 30A battery (a green one... Not sure of the brand) everything seems fine. Let's hope it stays that way