Popped into one of their store looking for some extra batteries. Was told that charging your batteries through external battery charger is the safest way to charge them. Also it means that While I'm using a set for my mod, I can have the other set charging and keep them in rotation. Well Done guys for the recommendations
I've recently got a mod that has external batteries (always had integrated batteries mods) this charges much quicker than if you were to plug it from USB straight to device. Always have batteries in rotation.
Have been using EFEST 18650 batteries for over 3 years, never an issue. This charger is also great quality and will charge many size of battery as it has a loaded spring. Perfect accessory for vapers.