Replaced battery, not holding a charge

My Problem

So, get the battery out and replaced. Keyboard worked for about half a day. red light flashing...

put the keyboard in a window to get direct sunlight charge. Holds a charge (green light) for about one day. now I'm back to flashing red light.

Any suggestions?

My Fix

went well, except that the battery wont charge.

My Advice

Make sure to orient the battery correctly. and when disposing (i.e. recycling it, make sure to put tape over both sides to prevent runaway overheating due to shorting out)