[RC-Monster Mike]

A cheaper charger (Like the duratraxx) will not be nearly as reliable as the Indy/Integy charger in my experience. The series connector is simple to make. You would need a total of three connectors(two male and one female) and three pieces of wire. I can make one for you in about 5 minutes if you want. Baiscally, you wire the positive on the female plug to the poitive on one of the male plugs. Then, wire the negative on the female plug to the negative on the other male plug. Finally, you wire the two remaining male plugs together (positive to negative). It looks like a triangle when you are done. The female end of the connector plugs into the charger (like the battery would) and the batteries plug into the male plugs on the connector.