1 DB. SONY VTC6 18650 3000MAH AKKUMULÁTOR GRADE+

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

Only use a suitable external battery charger
Always switch off the mod 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 into your pocket
Do not touch the battery with metal objects
Do not disassemble, drill, press, short-circuit or expose to water or high temperatures