I bought an extra one when I bought a Phasm Cam because I saw reviews and videos about how short the battery life is. It does its job, but the battery life is pretty short. It's about 30-40 minutes. One thing that can make this a little better would be a dual charger, allowing us to charge two batteries at the same time.

Just what the doctor ordered will come in handy on long investigations

This is a must if you take a lot of timed consecutive pictures or movies as the battery with the Phasm Cam only lasts so long. It's nice to have a back up battery for when recharging the first one.