I've gotten 3 weeks out of this set of batteries so far. The battery meter is at about 25% and I've yet to experience any difficulties. The backlight is set at 20 seconds. The 3 weeks did include a final bit of the upload/download frenzy that killed my first set rather quickly. I might add that I've yet to experience any problems with PENG, the simulator, or the remote itself other than the shortcomings noted by all. I spent 6 weeks or so learning PENG and working with it before I purchased the 3000. The pcf loaded the first time and the tsu3k has made it through countless uploads and downloads without a hitch as I've fine tuned the pcf to operate in a way that suits my needs. I'm guessing that 5 or 6 weeks is going to be about the max on batteries for my unit.