hey is there a special way or putting the batteries together my brother tried to make a battery pack a while back any for some reason when he tried to charge it it didn't work can anyone give exact details on what to do or know what was wrong that could cause the battery charging not to work?

another thing has anyone ever tried to use a plug for their bit battery pack so u can take it out to externally charge it? i was thinking those mini d.s. deans plugs are small enough to fit in the bits right?