I wanted something portable that could be used anywhere once charged up. So i built a little stand that also holds the battery,controller,12 volt socket, fuses and voltmeter. The controller prevents overcharging or draining and keeps the battery topped off as long as its plugged into the panel connection on the wall. I used a 8 amp fuse on the load side of the 10 amp controller so I don't have to worry about pulling too much through it. I also put a 8 amp fuse on the battery just in case. The 9 volt battery powers the LCD voltmeter and it measures the voltage on the battery. Its a really simple setup and so far its been great. I have used it with a 150 watt car inverter running a laptop with no battery in it for over 6 hours with no problems. I have also charged up multiple tablets at once using the same inverter. I have yet to see less than 11 volts on the meter, it seems like its always ready to go. I will be using this for all of my charging needs.