I have been charging mine using a 12 volt 800 mah power supply, and/or the plug for my Novak tray.
So, I am not using any peak detect or anything. I just plug it in for about 10-15 minuts if I notice the voltage at 10 or less. Then its good to go for another day.
This is with GP1800AA, and has worked great for over 2 years....