... 18650 unprotected board rechargeable battery 3.7V 2400mAh. Maximum height 67.0mm, diameter 18.3mm, (usually to protect the battery with a ... protection, over-charging voltage 4.2V, over discharge voltage: 2.75V, the battery cycle life of ... a new generation of protection chip set overcharge, over-discharge capabilities, comprehensive care of the safety of lithium batteries, and greatly extended battery ...