Lithium rechargeable batteries like in laptops are highly unstable in laptops, that's why they can store so much power in such a small space. Because of this if a battery is not charging right it can catch on fire, which is why a battery has more than two connectors on it: so the laptop can regulate charging of each cell in the battery. It is possible to charge it with only two wires, but I highly recommend not doing it as it is dangerous and could break your battery. I'm curious: why don't you just plug in the laptop? If you lost the power cord it would he easier and cheaper in the long run just to buy another cord.