This is a basic lithium battery protection circuit, but looking at the dual mos-fet part of the circuit, It doesn't make sense to me. It's a 8205A dual mos-fet, with its drain connected together and each of its source connected to the negative of the input and output. Normally, the drain of a mosfet is connected to the positive. in this case both are connected to the negative if they are turned-on. I don't understand! what voltage will be the drain with respect to the ground?