I have a electric stapler that works with a battery. This battery became bad some time ago, after doing a lot of searching for a replacement battery. I found none. I did not even find a reference to the battery. So time to fix it myself.
The end of the battery pack is clicked into the bottom and can be taken apart by jamming a screwdriver in the seem:
Then this pack came out of the enclosure:
For the positive terminal of the pack the tab welded to the cell can be used. Between the cells I used solder to connect them together.
For the negative terminal the connections in between the cells are in the way, so I had to cut this bar and replace it by a wire.
Connection of the wire to the bottom:
This arrangement just barely fits inside the battery enclosure, when inserting make sure nothing is or can short circuit.
The last step is to reattach the end cap. It does not click in place anymore, so I used glue to attach it again.
And then the big question: Does it work? Yes it works: