I actually never bought a spare because I had previously never seen the battery go more than 1/4 from full charge from a full day of use, and although I was expecting the battery to drain a bit from the long exposure I wasn't expecting one shot to totally kill it. The standard battery is 1.4Ah, and instead of buying spares, I am actually thinking about using a scooter battery and rig a DC/DC transformer that I can plug into the cam directly when I want it. Scooter batteries only weigh a couple pounds and deliver 10-100X the power of the regular cam battery and can be found for under $20 for the smaller ones. One thing that I definitely want to work on is the lighting, because I really hated the color temp of the flashlight we used to light the tree. Maybe a gel filter or something similar.