LSS271617 Battery,2025 New Upgraded Replacement Battery for Fitbit Charge 5 Fitness Smartwatch FB421（Not fit for Charge 3 and Charge 4）

There were no instructions provided. There was also no glue which would have been needed. We were not able to get the watch screen off and decided to just buy a new watch.

I wouldn't try this unless you're somewhat experienced doing piddly small awkward parts that aren't meant to be serviced. Four stars because the battery life is less than the original.

This appears to be a good, complete kit. The only problem I had was that I was unable to remove the watch cover. I used a heat gun to soften the glue but I couldn't get it off. I used considerable heat, too.I think the glue they used on these Charge 5 watches isn't the type used on cell phones and tablets. It simply does not soften up with heat.BTW, I successfully replaced batteries on two tablets and an Android phone so I know the procedure.My suggestion is to try removing the cover before you buy this kit. Otherwise, you might wind up wasting your money.I wound up purchasing a new Charge 6 Fitbit. Maybe the non-softening glue is planned obsolescence to get you to buy a new watch.

couldn't remove the screen despite plenty of heat because the pry tool is too thick. And there's no glue for the reassembly anyway.