Before you buy a Battery for your Zen MP3 Player be aware of what you are buying. is it an origanal or some unknown replacement battery. the origianl battery is 800 mAh and says CREATIVE on it. you will see some for sale that say they are 1000 or 1100 mAh. anytime i have seen a battery with more mAh. it was a bigger battery so how could a battery with more than 800mAh fit into your player