Why is my watch getting hot charging after screen replacement?

Why is my watch getting hot charging after screen replacement?

So I recently changed my wife’s screen last night and stuck it on the charger. I got the green snake and left it overnight. The next morning I checked on it and it wasn’t charged. I tried to reset the watch but it stays at the green and red snake. Now when I put it back on the charger it gets very very hot. Did I damage the battery or something else?