503440 3.7V lithium polymer battery packs 650mAh 1.CE & ROHS listed 2.1 year warranty 3. ... 4. OEM & ODM 503440 rechargeable 3.7V lithium polymer battery packs 650mAhNominal Capacity: 650mAhNominal Voltage: 3.7VCharging Cut-off Voltage: 4 ... smaller size10.Most safe no explosion no fire Customized capacity,packs, tags, labels,plugs, connectors, over current protection, temperature control protection ...