Convoy S2+ (and general flashlight) troubleshooting.

Took my S2+ Tan with Biscotti apart last night and wanted to replace the GITD o-ring with a black one. So I installed the black one (which is much thicker and the pill screws in less than before) and when all back together the fit for my 18650 was pretty tight and light wouldn’t turn on. So i figured the end of the battery tube wasnt making contact due to the tight fit. Took head off, made sure tailcap was all the way down (it was) and reassembled. Same thing. I could turn on light when i unscrewed the head a little and it would come on and work fine, but all the way tight, nothing.

It also worked fine with a shorter cell with everything tight. So i put the GITD o-ring back in and all is well as before (completely screwed together, works with longest cells i have). So my question is, what causes a flashlight to stop working when all connections are tight but the cell is too long? Hope this makes sense, i’m just curious about it.

The tail threads are anodized on the S2+ and do not conduct electricty.

The ring at the bottom of the tailcap has to make contact with the end of the body tube.

The longer battery and extra o-ring must have been just enough prevent contact.

Thats the only thing i can come up with too!

While i did tighten tailcap all the way and THEN inserted the longer battery, then put the head on (which should conduct just fine with little thread engagement), it had to push the tailcap away just enough to not conduct. Just blows me away that it could place enough pressure on the fully engaged tailcap threads to push the conductive ring surfaces apart until i loosened the head.

Thanks Andrew_Debbie!