This motion sensor light from Anear uses 4 D Cell batteries. While I’m not crazy that they use that type, because I had to go out and buy them, they have lasted a few months without dying or degrading the strength of the light.
Anear says that with the 30 second run time of the light each time it is activated it should last 3,600 activations. That seams pretty reasonable if you ask me.
This light is gonna run you $20 bucks on Amazon. That’s not a bad deal for what you are getting. Overall I think it’s a great little motion sensor light and my only issues with it are the fact that it uses D Cell batteries and sometimes it can be oversensitive because it will go on when nothing is outside (maybe it was being tripped by a bug or leaf blowing by)
Check it out on Amazon! http://amzn.to/1jhc5z9