In some cases, such as your internal battery being dead or defective, you may want to use the external battery pack even though your pitching machine has a battery already in it. If this is you, there are a few important steps you need to follow to make sure your machine will operate properly.Step 1: Get to the batteryUnscrew the agitator (the the round black part with the sloped top). Then remove the black plastic top plate that the balls sit on, there are two screws at the front of the machine and two in back. You now will see the internal mechanisms of the machine. On the left side you will see the green control circuit board. At the top of the control board you will see white connectors that attach the wires to the board. Then pull white connectors straight off of the board.Step 2: Disconnect the current batteryFind the leads (black and red wires) connecting the control board to the battery terminals. Using proper safety precautions, disconnect the black and red wire connector from the control board. There may be one or two connectors to pull depending on the number of batteries in your machine.Step 3: Connect the external battery packConnect the plug from the external battery pack to the charger port. This will allow for full use of the external battery's power.Step 4: Power on the machine to ensure normal operation.Attempting to connect the external battery pack while the existing internal battery is still connected will cause the battery power to average out and not properly supply enough power for the machine to run appropriately. Step 5: Re-assemble machineReverse the above procedureAny questions, contact us here: https://contact.maxbp.com/