Free 9V connector

Step 4 Cover it with shrink tubing

I noticed that the best way to cover it is with a shrink tube, you will need a tube 2-3 centimeters longer (1 inch) than the connector. shrink it around the connector leaving some tube on both sides. cut the holes in the tube where the connectors are (the - connector must not have any tube around it as it has to go into the hole of the - connector on the battery, this is not important for the + connector)