Efest 18350 IMR 800mAh 3.7V Nipple top

Normal Voltage: 3.7v
Maximum Voltage: 4.2v
Capacity: 800mAh
Positive: Button Top
Dimensions: 17.94 x 35.17mm.

These IMR cells have much lower internal resistance than regular Li-Ion 3.7V cells and they may end up with a higher ending voltage when charged in certain chargers (especially older versioins of the WF-139 charger).  Please check the voltage of your IMR battery right out of the charger with a Multimeter to see if they are above 4.20V when fully charged with your charger.  These batteries should never be discharged below 2.5 volts or the life cycle and performance will be reduced..  Overcharging above 4.25V may shorten life/cycles. Batteries that read above 4.5 volts may be damaged and we recommend to discontinue use of the charger.  DO NOT use the charger if it is overcharging IMR cells.  For best results and battery life expectancy, we highly recommend using an Intelligent Charger such as our Efest Bio Charger or LUC LCD Chargers for charging all your Li-Ion type batteries.