I know you can take the button off and it will work but I already lost one button so I fixed the charger to fit the battery with the button on it.
I used a pocket knife to open the charger at the seam. It came apart with nothing breaking.
The little tube with the connections inside lift off the board. There was a piece of tape on mine holding the two halves together.
I cut 1/4" off both pieces on the end the battery goes in to. I used a heavy duty utility knife.
Put the spring, contact and the part the battery screws on to back together and used some tape to hold them. Tube snaps back on to the circuit board.
Used a dremel tool with a little sanding attachment to widen the hole on the outer housing on both halfs. Glued the 2 pieces back together with super glue and that's it. Still works with either manual or auto battery.
I used a pocket knife to open the charger at the seam. It came apart with nothing breaking.

The little tube with the connections inside lift off the board. There was a piece of tape on mine holding the two halves together.

I cut 1/4" off both pieces on the end the battery goes in to. I used a heavy duty utility knife.

Put the spring, contact and the part the battery screws on to back together and used some tape to hold them. Tube snaps back on to the circuit board.

Used a dremel tool with a little sanding attachment to widen the hole on the outer housing on both halfs. Glued the 2 pieces back together with super glue and that's it. Still works with either manual or auto battery.
