Panasonic NCR18500A Li-ion 3,7V 2040 mAh battery.
This battery does not have a protection circuit!
-Do not charge over 4.2V!
-Do not change polarity!
-Do not heat the battery, or store under the influence of high temperatures!
-Do never shortcut!
-Make sure they do not come in contact with water!
-For longer storage periods should be stored below 45 ° C temperature.
-After long storage times need the cell probably make a few charge cycles to increase capacity again.
-Do not discharge below 3V.