Accu 30A 21700 4000mAh MXJO

For better use of the batteries, teach your customers "good practices":

-Use only a suitable external battery charger
- Always turn off your mods or e-cig before storing it
-Protect unused batteries wherever they are stored with a suitable cover or case
-Do not use a damaged or scratched battery
-Do not use a battery beyond its amperage limit
-Do not put a battery directly in the pocket
-Do not place a battery in contact with metal objects
-Do not disassemble, drill, squeeze, short-circuit or expose to water or excessively high temperatures