Cordless drill upgrade for about $40

Step 3 The battery assembly wiring

Here we will make the battery circuit and some of the attaching assembly.
Start by stripping the insulation on all the wires, then cut the wires on one of the battery holders then cut the battery holders. Connect all the battery holders into two sets of eight battery circuits. Place electrical tape on all the connections and place all of the battery holders in the battery box except for one. Trace the bottom of the drill then use another drill to make a quarter inch hole in the top of the battery box after removing the lid from inner components. Place the lid back on then feed the four wires though the hole. Place a connector on three of the wires and the fourth being connected to the last battery holder, then to the fourth connector. Be sure to lablel the connectors , remember there are two separate 12V circuits.