This Li-Ion 760 mAh Original Nokia BL-5B Battery is great if you need a replacement or simply want a spare.

Specification:

Item: P-131
Packaging: Polybag
Compatibility: Nokia 3220, 3230, 5070, 5140, 5140i, 5200, 5300, 5500, 6020, 6021, 6060, 6070, 6080, 6120 Classic, 7260, 7360, N80, N90