Originally Posted by Dubdub
It actually can harm the battery to let it get below 20%. And it doesn't hurt to keep it topped up when you are near a plug. I keep mine plugged in all day when I am in the office.
Upgrading with half a charge has nothing to do with it.
Have you tried a battery pull?
Check the FAQ for an article on maximizing battery life.
First of all, thank you for your answer. But it lasts more than a day to finish the %30 battery and it's very annoying to see flashing light. It's okey when I'm home but it's annoying to get erroneous led light. It's not like that for a month.