Just plug it in for an hour to top it up to 80 % or so, and put back the primary cell, and you're good to go. (androidcentral.com)
Then, even fewer had the ability to work when plugged in for charging. (thewirecutter.com)
And never mind battery life; if you didn't leave your tablet plugged in for at least 10 hours yesterday, it probably won't even turn on for class today. (goodereader.com)