Once you try a DC charger and power supply, you will understand that it is the better system to use. You pay way more for the convenience of a built in power supply. They usually are very weak and don't last very long either. Pick up a converted computer power supply, and a decent charger like a 206B, and you are way ahead of the game. The trade offs for a built in power supply are not worth it. Almost all AC chargers have a system that allows an out side source as well(DC voltage,) and a higher charge rate as well.