120mAh LSSP321830AE Battery Replacement Compatible with Fitbit Blaze Smart Fitness Watch FB502

Installed, charged, and was excited to see that the Fitbit Blaze worked again after the OEM battery failed after 8 years. The replacement battery life initially was very good. Now, two weeks later, battery charges, overheats the Blaze, shows ~80% charge, and dies within the hour.

What a piece of junk! The battery would not last 8 hours and now it will not take a charge. I would NEVER buy one of these again! Even one of the tools would not work, the small Phillips screw driver would not fit into the screw. I give it NO STARS!

I bought this for my wife's fitbit blaze and didn't know until I took the original battery out that it is a 3.7v 167mah battery. This replacement is a 3.7v 120mah which means the battery won't last 5 days but only 3 days and you have to charge again. The phillips screwdiver did not work on the board screws but my eyeglasses screwdriver did. I used a youtube video to help me and found it easier to cut the old battery leads leaving them long to unsolder them from the board. I was successful and it works. This repair is very delicate and if you are not use to plugging in micro pinned ribbon cables don't try it and send it in for repair battery replacement. I also found 3.7v 200 mah batteries on the web which have the same dimensions and would last longer.

All the tools that came with the kit was very useful. So far so good.

The tool set is great, but you will need to watch an online video to learn how to change the battery as no instructions are included. It is not easy to change the battery. The battery is somewhat oversized so it takes some coaxing to fit it in. Soldering requires experience and lots of dexterity. My old battery was rated 165 mAh and a charge lasted 3 days. I expected this one, with a rating of 120 mAh, to last 2 days on a full charge. Was I wrong. A full charge lasts at most 1/2 day. The batteries that come with these kits must be factory rejects. Too big in size, and below par in energy capacity.On the negative side, I need to get a better battery.On the positive side, I got the tools and the experience.

Will not take a charge. Junk battery.Tools are ok at best. The Phillips screwdriver immediately stripped on the first screw inside a Fitbit Blaze. The tiny torx held up however and the little spudge blades did their job.

The star screw driver worked great. The mini Philips worked on only one screw. If you are not good with a soldering iron and have a steady hand, the work is difficult. I used a cheap soldering iron and it was not good. Better tools = better experience. Unfortunately, I did not test the battery (I suggest you do) prior to installing it. I am getting no better life out of this battery then I was with the original 4 year old battery. The watch might just be the problem. thankfully, this set was cheap enough as I missed the return window. I did use one of the plastic pry tools to detach the old battery but I needed an exacto knife to open the watch after removing the Torx screws.

Fairly easy to install.