I'm still getting used to my G700 but one thing that I noticed almost immediately is that the battery life sucks. To see if this was a defect in the unit I bought or something characteristic of the model, I went online. In very short order I got the impression that this is indeed an issue with this model. However I also discovered that I had it on the std game setting rather than power saver. Setting to PS mode did help but even then, an alkaline battery with more than 1.5v of charge left on it still only lasted a few days. The included rechargeable battery didn't do nearly as well IIRC. I was getting ready to start bitching to Logitech about the problem when I decided to see if the mouse would take some high voltage rechargeables that I had. These are the NiZn type that you never seem to hear about but which are fantastic rechargeables. The only problem is that they charge up to a little more than 1.6v and at that voltage, many electronic devices reject them. I guess they must have over voltage circuits that kick in. However the G700 seems to be perfectly happy with 1.6v and I've been running for a couple of days now on one of those. Here is the wiki entry for NiZn batteries and here is the list of sources for the PowerGenix NiZn's. Enjoy. edit: btw, since I've only been able to find these batteries in the popular AA size, I should mention that you can get a set of battery sizers that will let you use AA batteries for applications that require a C or D size battery - here is just one example.