Magnus Gear Mini External Rechargeable Battery Charger + Free Li-on 18650 Rechargeable Battery External Battery charger for your lithium battery + One Free 18650 li-on battery Charge your battery in 4 hours, carry extra battery anywhere you go for your Vision II light Portable and easy to carry, charge with any USB port Reverse polarity for overcharge protection External battery charger will work on any rechargeable battery types, AAA or AA