What have I done wrong?

[ba-ta]

So I got a Thrunite Ti2 V2 for Christmas last year and I went to change the battery on it for the first time a couple of days ago. Put the new battery in and now it won't work.  I can twist the head of the flashlight all the way down and it rarely turns on, occasionally it will turn on as I go.to twist the head back out.  Putting in the old.battery doesn't seem to make a difference now.  What could I have possibly done to my light?  Any help would be greatly appreciated.

[SAK Guy]

Try cleaning the contacts with a pencil eraser.....

[pingu]

I'd go down the cleaning route also but instead make sure any grease is removed from the threads inside and out (but not from the completely inadequate O ring  ).

I've retired my Ti2 V2 because I didn't like how loose the head was but I got it out to check.  Screw the head on without the battery and check that it fully screws down completely closing the gap.  Then do the same with the battery installed and check that there is now a small gap when fully tightened.  That proves that dimensionally the battery is OK.

[Gareth]

Is that the two mode twist on for low, twist more for high?  If so there might be a little tab of copper that acts as the + contact on the inside of the head.  Make sure that it is clean and not broken.

If it's not that style then check to make sure the top of the battery tube is clean and the same goes for the inside of the head.  I'm thinking there might be some crud blocking the contacts.

[AimlessWanderer]

As a matter of fact, I've just fixed a similar problem on my Preon Revo (hey Tofty   ) this evening 

At first I thought a sprung surface under the AAA cell wasn't lifting it up high enough, so I was having to overtighten to get the head further into the body of the torch. Turned out to be a lot simpler. On the head, the o ring had started degrading a bit, and rubber residue for want of a better term had built up on the contact land after the thread. Scraped off the thick of it with a small screwdriver, rubbed round it with a coarse rag, and it's now working much better. Just needs a squirt of silicone lube spray on the threads now 

[ba-ta]

So I kinda fixed the problem. Cleaned the contacts and the bottom one had a bunch of something that came out, tried putting the battery back in and still didn't work.   Sat around wondering what else I could do and then decided to put a little wad of aluminum foil in the bottom seems to be working now.  It's like the battery just wasn't long enough to touch both contacts even with the head fully screwed down. The other fun part is that now I have to go get some thread lock because in the course of tightening and untightening I managed to get the head stuck and ended up unscrewing the threaded part on the emitter. Not the happiest with this light.  When I bought it,  I thought it would be simple to use and maintain. Changing the battery has been a smurfing nightmare!

[Aloha]

I dont recall what batteries I used in which I experienced the same situation.  Different light than yours but same annoying issue.

[ba-ta]

I dont recall what batteries I used in which I experienced the same situation.  Different light than yours but same annoying issue.

Yes very annoying. Interesting to know that it's not just my flashlight that has those issues too.  I always thought batteries were made to fairly tight tolerances.

[SAKnight]

I dont recall what batteries I used in which I experienced the same situation.  Different light than yours but same annoying issue.

Yes very annoying. Interesting to know that it's not just my flashlight that has those issues too.  I always thought batteries were made to fairly tight tolerances.

I have a rechargeable AA that is probably almost a mm shorter than standard, i'll try to capture it in a pic

Edit: Okay, that was an exaggeration I guess. But you can see the difference. I lined them up best I could. You can see some of it is that the cell is shorter, and the terminal makes up for it, but not enough.

[ba-ta]

I dont recall what batteries I used in which I experienced the same situation.  Different light than yours but same annoying issue.

Yes very annoying. Interesting to know that it's not just my flashlight that has those issues too.  I always thought batteries were made to fairly tight tolerances.

I have a rechargeable AA that is probably almost a mm shorter than standard, i'll try to capture it in a pic

Edit: Okay, that was an exaggeration I guess. But you can see the difference. I lined them up best I could. You can see some of it is that the cell is shorter, and the terminal makes up for it, but not enough.

Wellll there you have it folks, photographic evidence