Eek! What should I be looking out for? After the first few charges, I can leave it on the external charger overnight?
Extremely high temperature. A little warmth during charging is normal. But if the battery or charger get too hot to touch, it's a warning sign. Unplug the charger. It's a good idea to charge
batteries at the lowest setting you can tolerate with the time you have. I charge mine at 0.5 amps on my Efest LUC charger.
The only thing you really don't want to do is try charging or using a really old battery, any battery that looks dented or has a damaged or badly discolored wrap or damage to the positive end.
It is recommended that you monitor charging, but if we always watched every single battery charge up at 0.5A every single time, we'd never leave the house unless we only had one mod. And what sane vaper has only one mod?
