Replacement battery to suit Sony replacement battery number: PEGA-BP500. Rechargable Li-Polymer battery for highest quality. This is an aftermarket battery, but will be fully compatible with the Sony battery charger. Battery has no "memory effect", therefore it can be charged at any time without damage to the battery or the need to discharge it first.

Sony PEGA-BP500 Battery Specifications
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Volts: 3.7V
Battery Capacity: 1200mAh
Battery Chemistry: Li-Polymer
Aftermarket Battery