Won't power but a battery icon appears.

So I think my battery is dead. I left my watch without charge for a day or 2 and then when I put it on the charger, the screen turns on for a second, showing a battery with a bolt inside it and powers off again.

I left it on the charger for a whole night, tried several different chargers and cables, but still the same.

Do i need to look for a new battery?