Old Charge HR won't turn on

[Superrealraisin]

I've had this Charge HR Fitbit since 2016. I stopped using it a few years ago and it was kept in a storage bin. 

Recently my grandmother expressed interest in wanting a way to track her steps and such, and I dug out the old Fitbit.

I knew in all that time the battery would have died, so I've been charging it. When I first plugged it in, the green lights came on and the screen showed the empty battery. 

Now, 2.5 hours later, the screen showed full battery so I unplugged it, but now nothing happens. It doesn't turn on at all. Obviously since I got it 7 years ago it's well past the warranty.

So does this issue sound like something that I may be able to fix? Or should I just give it up, since it's so old? I tried resetting it (Holding down the button while it's plugged in until the version pops up, which it did) but that didn't seem to help. So I don't know if the battery is just completely ruined or if it just needs to be charged even longer.

[LZeeW]

Hello @Superrealraisin and welcome to the Community.  Rechargeable batteries degrade over time, even when they're not used.  You can't view the battery health like you can on your phone, but I'm very sure your Charge HR has a dead battery.