Turning off extra services like Bluetooth can help. If he has 4G turned on, that'll really eat up the battery. So if LTE isn't available in his area, it's a good idea to shut that off. Leo also suggests backing up the Android phone and performing a factory reset, which often fixes issues. Leo also suggests getting an extra battery for his phone. Or if battery life is really important, the Droid Razr Maxx HD has the best battery life on the market.