Today, I replace the battery of Fitbit Zip. It is CR2025. I check the voltage of new battery and the exhausted one. New one is 3.21V. The old one is 2.83V. Let me record it and see how long I need a new battery for Fitbit Zip. Share on FacebookTweet Related posts: Fitbit zip wireless activity tracker Fitbit Zip tracker lost syncing? Water Proof Fitbit Zip Update Fitbit Zip firmware 5.86 HTC Desire HD battery replacement Got another HTC Desire HD battery Replace the Battery of Anne Klein watch