From what you posted, it sounds like you removed or disconnected the battery to charge it. I would start with checking the battery connectins to make sure they are clean and tight. I recommend removing them and wire brushing them both to be sure. There are a lot of times when they look OK but they aren't.Also look around the battery area for a wire that may have been connected to the battery that wasn't replaced if it had been disconnected.
The common sence things come first, then you have to test point to point to see where you are loosing the power. You didn't mention if the bike starts and runs OK or not.
If you have a manual, this would help in testing it out. If not, it's a great investment for anyone that wants to work on their own bike.
