This is a very simple but useful adaptation of the charger that strips away all the components except those which hold the battery and connect to it two (pos & neg) terminals. It's nothing more than a socket for the battery with easily accessible output leads.
For my outputs I chose to use a two foot length of paired wires with insulated alligator clips at the end. In hindsight, some type of plug or jack mounted on the case would provide even more flexibility. With most of the components removed from the circuit board there is plenty of space for adding new components.
I have a drill and a circular trim saw, each with a few batteries and charger. I really only need one charger in my life so the second one became the doner for this project. I still have an intact charger to keep all the batteries charged.
Step 1: Opening the case
Should you need to drill out the screws, a 3/16 inch drill will do.
Don't forget the fifth screw located down inside battery socket.