Just an FYI but almost any 8.5mm female battery will work. I would suggest using the Modern Vapor Sidesho battery. I am not certain if you can change them in the BLU PCC (I do not own one) but they work and fit perfectly for the BLU carts. I buy them from time to time. Great flavor (wish JC would release it). The Sidesho is a longer battery but double the power and usage time.
Electronic Cigarette Battery - Sidesho Spare Auto Battery
Electronic Cigarette Battery - Sidesho Spare Auto Battery