bradjackson
Newly Enlightened
I wanted to be able to connect an external battery pack to my MTE flashlight for longer runtimes & a lighter package on my helmet. I didn't like the idea of making irreversible changes like drilling a hole into the body.
This is my solution. Its not quite a finished work yet, but it is useable for now.
I'll let the pictures tell the story.
The light with the tailcap stripped
The donor cable from an old... actually I don't know where it came from, but I found it in a box "junk" in my garage.
Some pieces of irrigation pipe which are the same diameter as an 18650 cell.
I used a a Crayola marker as the "dummy cell" with a screw on the end for the + terminal
The cable with the + lead fed through the dummy cell
I sawed a groove into the screw to make a slot to attach the + cable. I crimped the cable in place with a large pair of pliers.
Then soldered it for good contact
The + terminal on my dummy cell
The negative lead coming out the back of the dummy cell
I made a hole in the body of the pen just big enough to feed the negative lead through from the inside. Then I soldered it to a piece of battery terminal connector which was left over from one of my salvaged laptop batteries. I heated up the plate just enough to start melting the plastic, and then let it cool. There are jagged edges on the plate which allowed the plastic to ooze through and once set, it created a nice firm seating.
The threaded ring from inside the tailcap gets slid on from the front end and the tailcap screws onto the back creating a snug fit.
My battery pack, made up of 4 x 18650 in parallel. They are enclosed in 2 soda bottle preforms which are cable tied together. Then a female DC socket is soldered to the terminals
The whole lot connected up together
I haven't added a switch yet, that will come later. For now, you turn it on by screwing it together or plugging it in.
Its possible to return the flashlight to its original configuration just be re-assembling the tailcap.
I would like to find something to replace the tailcap altogether, that way I dont need to disassemble it to use my external battery.
Does anyone know of something which has the same thread and can be screwed on in place of the tailcap?
This is my solution. Its not quite a finished work yet, but it is useable for now.
I'll let the pictures tell the story.
The light with the tailcap stripped
The donor cable from an old... actually I don't know where it came from, but I found it in a box "junk" in my garage.
Some pieces of irrigation pipe which are the same diameter as an 18650 cell.
I used a a Crayola marker as the "dummy cell" with a screw on the end for the + terminal
The cable with the + lead fed through the dummy cell
I sawed a groove into the screw to make a slot to attach the + cable. I crimped the cable in place with a large pair of pliers.
Then soldered it for good contact
The + terminal on my dummy cell
The negative lead coming out the back of the dummy cell
I made a hole in the body of the pen just big enough to feed the negative lead through from the inside. Then I soldered it to a piece of battery terminal connector which was left over from one of my salvaged laptop batteries. I heated up the plate just enough to start melting the plastic, and then let it cool. There are jagged edges on the plate which allowed the plastic to ooze through and once set, it created a nice firm seating.
The threaded ring from inside the tailcap gets slid on from the front end and the tailcap screws onto the back creating a snug fit.
My battery pack, made up of 4 x 18650 in parallel. They are enclosed in 2 soda bottle preforms which are cable tied together. Then a female DC socket is soldered to the terminals
The whole lot connected up together
I haven't added a switch yet, that will come later. For now, you turn it on by screwing it together or plugging it in.
Its possible to return the flashlight to its original configuration just be re-assembling the tailcap.
I would like to find something to replace the tailcap altogether, that way I dont need to disassemble it to use my external battery.
Does anyone know of something which has the same thread and can be screwed on in place of the tailcap?
