One thing I tried doing that worked was after taking the battery, that came with
the keyboard, out of the tray I removed the yellow warning label stuck to the
battery. I thought that it might possibly be interfering with the solar panels charging
the battery. And that really helped with not only getting a charge to the battery
but also with how much it charged up to. I know they want to warn people about
the battery but I thought they could have put that lable anywhere else.
Your mileage may vary but it worked out well for me.