Energizer ENB-SFW50 Digital Replacement Battery NP-FW50 for Sony A33, A35, A55, A390, NEX3 and NEX5 (Black) Replaces the Sony NP-FW50 Li-ion Battery Battery Specs: 7.2V 850mAh Compatible with Sony A33/A35/A55/A390/NEX3/NEX5 and similar camera models Can be used with original lithium-ion battery charger This Li-ion battery is 100% memory-free and will not suffer from the inconvenient memory effects that are typically associated with similar battery types.