I bought this as a back up not long after buying my new Sony A300. I took the camera on holiday, used it a lot, and continued using it for several weeks after, all without having to change or charge the battery. These batteries have serious stamina. They also charge up quickly and the percentage use indicator is very accurate. I'd recommend it if you are travelling and don't want to carry the charger and an adaptor for different electrical sockets but, if you are never going to be away for that long and have the opportunity to charge your battery when you are not using your camera, you probably won't need a spare.