Battery stucks at 100% for more than 12 hours after charging

Yes. After a full charge, my VA4S is also staying at 100 percent for 12-24 hours.

That's normal.

Battery full at 4.2V. But you can overcharge to ~4.35V. So till discharge to <4.2v the watch shows 100%.

This was also my first thought. 

But:

• on the Fenix this does not happen. 
• Why is the stuck behavior the same when the battery is charged only partially? 

I was going to ask about this issue myself, as I spot it a while ago. And it's a bit irritating that battery indicator stuck at the same percentage no matter if I go to full charge or partial one. I think it was different on some previous firmware but I'm not sure.

If you want to get better percentage you can wait a bit, maybe an hour and then reboot the charge and it will re-calculate percentage to be higher. 

e.g. I'm charging my watch up to 75% to save the battery but after reboot I get something around 82%, so it's the bug of battery charge estimation.

Has anyone tried to report this bug yet?

I am having the same issue with my brand new Vivoactive 4s model, after charging to 100% it gets stuck, and only a reset will solve the issue (restarting does not help either). Though I have not yet tried waiting for 12-24 hours, but wondering whether this is system bug and will be fixed later?

I doubt that Garmin will fix this. It is a very minor issue. You'll get used to it. 

Thanks ovekvam. The only thing I am wondering is if the battery is at 100% at all times, I am not aware of when the battery needs charging, because even when plugged in and charging, it shows 100%. I don't think this is a major problem, but not a minor issue either. Also, it would be annoying to reset the watch weekly. 

There is no bug to fix. Get used with it.

Watch shows 100% if battery is >4.2v.

If charging leads to 4.25v, the watch will show 100% till it drops to <4.2v.

And why does it have the same behavior after only a partial recharge? It will stuck at the level the charging was stopped even in this cases. 

it's definitely a bad way of calculating remaining battery charge based on voltage, and it's happening with partial charge too, just today I charged to 70% and then after waitin an hour reboot the watch and got 76% out of the blue. So I'm sorry but your logic with big steps between voltage and percentage doesn't work. That's the only device I've seen so far with such weird battery behavior, no mobile or other watches I had had that weird battery discharge delay.