I am assuming you are totally stock, so this may not be of interest to you but some of the kernels put out by the devs around here can really help the length of your battery life. You mileage may vary, but I moved to comavolt a few days ago and have seen a dramatic increase. Not hard to flash, won't mess with the stock setup you may have, just undervolts the CPU to lengthen your battery life.
You might consider it