After a few daus of use my K40m I have a problem with battery carrier.
Because of high current flow springs become flatten, soft and get weird colour due to heat. Now cells have no contact 
Any clue what springs should I use as replecemant?
Mike
Whichever springs you use make sure to bypass them with braid or wire to prevent the weakening/flattening. It’s fairly simple, but can be a little annoying to accomplish at first; after you do a couple you can knock em’ out fast.
100% true
Done 
Springs bypassed. Light is working as it should.
Thanks guys.
Mike
I just wanted to update, than after 16 months of use k40m still rocks.
Mike