So I have this little cheap 1xAA emergency charger I have been trying to think of a way to mod. I know Alan has done one already aswell. I had given up finding a switch to try to use so I came up with this. Had a big contact spring from a 4xD cell box. It fits nice and tight inside the top. The only think I did was push the Connector down inside the top of the spring, couldn't have asked for a more Perfect fit. I didn't even solder it (has a strong connection). XD Might need the connector later. I then bent a Paper clip and soldered it to the center post of the connector. Press down on the Carto/atty to complete the circuit. The spring is a tad bit stiffer than I would like but I think its probably a good thing in the long run.
this is what the charger looks like reassembled to how I received it. Can still be used for its original purpose.
and assembled for vaping
this is what the charger looks like reassembled to how I received it. Can still be used for its original purpose.

and assembled for vaping

