If you are interesseted in LED tourches or e-cigarettes your will sooner or later become acquainted with the 18650 Lithium Ion battery cell. Actually the 18650 is also used in Teslas electrical cars, and that is obvious because of the high energy density. A warning is justified here! When handling Lithium batteries remember to take some precautions: never short circuit the battery, don't exceed the maximum discharge allowable current, be carefull with high temperatures and only charge the batteries under supervision.
The type we use is Panasonic NCR18650B 3400mAh and to charge more than one battery with various multi chargers (many cells, NiCd, NiMh, LiPo, LiIon, Lead etc.) we decided to design a suitable PCB with necessary connectors for balancing the cells (check your battery charger manual for more info).
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