Was looking for an extra battery for my San Francisco as I'm going on a long trip soon and came across this on amazon.
Its a spare battery and a portable charger.
The portable charger is 1900MAH and the battery is 1300MAH meaning that you could charge a full battery and still have 600MAH left of charge ( in theory anyway )
Made from high quality materials
Re-chargeable and long lasting
Over charge protection
High quality battery. Ideal for a replacement or a back up battery. Made from lithium-ion polymer and is fully tested and safe to work with your mobile phone. When using from new its always best to charge the battery for 10 hours to improve its quality and lastibility.