Jetlasers 445nm 2W will not turn on?

[Pman]

I think the point that Len was making is that it doesn't matter if you cut back the shrink wrap on the negative end with some batteries if they are flat top as the positive end is the issue. I have cells where the positive end won't contact the negative end because the positive end sits back slightly in its wrap so removing the wrap on the end of the negative will not help. There's lots of places that sell very small thin magnets so that it barely lengthens the cells but you can go to Harbor Freight for some small thicker ones for cheap that will essentially lengthen the flat tops to be the equivalent of button tops. Radio Shack has them too if you still have them in your area. Pay attention and you can find magnets used in all kinds of stuff such as laser sleds and electic toothbrush heads.

 

[hakzaw1]

...to be 100% sure of no contact-I glued two of the 18650 sleeves (provided by JL) so that the magnet between the two flat-top batteries could never touch the insides of the host.. I did not like the idea of the magnet being at either end..hak