I have a two amp charger. Its pretty fast. I think under two hours. But that is to full charge, and I don't always worry about that.
I use to run Battery Left. It would tell you charge time left as well as run time left.
Then I found out that Battery Left, and some of the others will use battery just testing battery state. Since I'm already getting easily 24 hours, I've stopped fretting about battery, and just charge it when I can.