Step 1: Introducting the PCB board
The circuit board has connections for DC9-12V input, battery terminals indicator LEDs and power LEDs. Follow the picture to connect the board with battery, indicator LEDs and switch.
House them in a case of your choice and you have a fantastic LED lantern that turns on automatically when AC power goes or sun goes down. You can get about 10hrs of light time with this setup.
Step 2: Finally
Using a panel over 5W is overkill since the charging capacity isnt higher that. This makes it quite safe so not to overcharge the battery. Its best not to leave the charger circuit plugged into AC for long time either as that could reduce battery life.
I will add tips as i do more experiments with the board.