Weird battery problem

[androidgirl3107]

This is not the first time it happens. I play my phone until it got to 0% and it turn off itself. Then when I plug in the charger and turn it back on right away, 20% just came out randomly from nowhere(It suppose to be just 1% that time)
I want to know if any S3 users experience this too.

 

[B. Diddy]

I don't know this for sure, but I think battery readings toward the very low end can be somewhat erratic. The larger picture here is that it would be a good idea not to let your battery go to zero habitually, because that will increase the risk of allowing the battery to fully discharge to true zero (which is irreversible). For example, if your battery ran out, shutting the phone down, but then you got distracted and forgot to plug the phone in for the night--the little charge left in the battery could then completely run out, leaving you with a useless battery.