mcorner writes "As part of a University research project my group is studying, how, when and why users charge their devices (laptops, phones, music players, etc.). We have been looking at this in a variety of ways, including having users install a battery logging tool on their laptops (we have done phones as well). After studying some of the preliminary results we saw that users frequently leave a lot of energy left in their devices when they plug in. So one way of taking advantage of this observation is to try and predict when users will have "excess" energy when they recharge, and use that energy proactively to benefit the user (screen brightness etc.). We have had some success in building such a system. At first blush, many people say: "but I just want my device to use as little energy as possible!", but in reality people are always trying to balance their experience with battery life, and usually are using more than the minimum. At this point, we thought AskSlashdot would be a good place to look for: (i) you opinions on using "excess" energy, (ii) what other things to do with "excess" energy (synchronizing, etc.) (iii) how and when do you recharge your other devices, and (iv) more volunteers for the logging survey. If you are interested in installing our tool (Mac 10.4.x or Windows XP, I promise it is quite innocuous, with source available) please download it and install."