Fenix TK75 Runtime Kit

[Laser_Project]

Do what I did, I bought a second older 2015 TK75 which uses the white battery holder, use both the flashlight battery tube and the battery holder from it combined with the newer black colored holder with the USB charging port on the side. The good news is the old and new TK75 battery tubes (not meaning battery pack) thread together to extend the length of the tube. The bad news is the newer 2018 black battery holder/packs will not allow a second newer 2018 pack to be used together, only a newer 2018 pack combined with an older 2015 pack. Of course, if you have two older white 2015 packs, they can be used together.

If using a white and black pack together, the white pack must go into the flashlight tube first next to the flashlight head, the black last at the end cap, otherwise they won't work together.

NITECORE designed the new black colored battery holders/carriers so you cannot pass voltage from another pack through it, it can only supply voltage on its output, that is why it goes in the tube last. They also designed the new packs so they cannot be used with a flat top Li-ion battery by making the positive end contact recessed into the plastic. If you have flat top unprotected batteries you will need to use a magnet or something on top of the battery to bridge the gap and make contact.