36mAh Battery Replacement Compatible with Fitbit Alta Activity Tracker and Smart Fitness Watch FB406

Read my erroneous original review below. If you are experiencing the same problem of the new battery appearing not to fully charge and the Fitbit only staying on while on the charger (as other reviews have also reported) there is a good chance you have accidentally shorted out your Fitbit while removing the old battery or installing the new one. There is a micro-fuse on the circuit board labeled “F1” that can be seen using magnification. This gets blown easily and you’ll not be very successful in trying to replace it since it’s soldered to the board and is so small. Your best option is to bypass the fuse by applying a bit of solder across the leads of F1. This will restore operation of the Fitbit. Be careful not to apply pressure to the leads since you may accidentally push the fuse out of the board. Also make sure the gold dot on the inside of the plastic screen cover is positioned over the microswitch when you put the Fitbit back together or else it won’t power up at all. Changed my rating from 1 star to 4 taking off a point for the useless plastic prying tools that come with this. They are so weak they just bend instead of opening the Fitbit. Fortunately, I had better quality tools already. The only useful item is the T2 Torx driver that you need to remove the circuit board to access the battery. All that said, I’m back in business.——————————I ordered two batteries to replace the OEM battery that only lasts 1.5 days instead of the 5 it should. For some reason they were shipped separately. When I received the first, I installed it and put on the charger. It appeared to be working and the Fitbit would cycle through screens while on the charger. Next morning battery had still not reached a full charge and the Fitbit would not wake up if removed from the charger. When put back on the charger it would reboot with a slightly lower battery level. If I tapped while on the charger and removed while the display was still active, the Fitbit would stay on and work until I let the display go to sleep, and then it would die until put back on the charger. Hopefully the second battery will be from a different lot and actually work. From the reviews, it’s a bit of a coin toss if you will receive a good battery. Li-Po batteries have specific storage requirements and it’s likely this manufacturer/distributor is not properly caring for their inventory. I’ll update results with the second battery ASAP and will be returning one or both batteries accordingly.