The battery lasted until the day my coils came in, which is like 3 months of overworking abuse and denting, etc. My Aspire Mega tank leaked onto the battery. I bought the IJUST2 with tank and replaced the tank because the mega tank looked easier to open. I don't really know if it was a more watery brand of 50/50 because I got them from different places. They all poured like water, some twice as watery even though they all were labeled 50/50. Maybe there is a better brand, but they all leaked in my new SMOK TFV4(I got this specifically for the leaking problem, duhyee),immediately. I put like 80% VG in the TFV4 and it stopped leaking altogether. That's fine with me to give away my 50/50 collection. Even the Aspire Mega Tank stopped leaking with the new juice. I was really beating the crap out of the battery, fighting for a puff with all of the leakage. It wasn't able to work being filled with liquid and that probably killed it, ultimately. Now it just works while it's plugged in, but I don't use batteries while they are plugged in for safety. Luckily I had to buy a SMOK mini to use the SMOK TFV4 because as far as my wattage/usage level is concerned, the SMOK coils only come in .4 watts or 1.5 watts and they require wattage adjustment because that is quite a gap and they would be either overpowered, or ridiculously underpowered on this battery