get the magic mobee inductive charger , greatest invention since the wheel , no more worries about charging batteries , just place the mouse after use on the charger and done , always fully charged , no more thinking about taking out batteries to replace / recharge and £48 are not much if you calculate how much normal batteries cost which sometimes only last one month , and a normal charger cost money too and so do rechargeable batteries too and are far from cheap if you want some good ones