C cell battery meltdown

[Let It Bleed]

I decided that before I install a Malkoff 2-3D cell drop-in that I would try to figure out how to get three (3) C batteries in a 2-D Maglite. After a little trial and error and then with a lot of force, I was able to get the cap screwed on by simply reversing the spring. This particular Maglite had a 2-D Mag Led drop-in in it. I really didn't care if the increased voltage fried it. And for some reason the old incandescent bulbs would not light.

It lit up, and I ran it about 10 seconds, cut it off, and then ran it for another 10 seconds. I unscrewed the cap and the first battery (i.e. the battery closest to the cap or last battery installed) was hot as a firecracker. There was even a little melting. The other two batteries were completely cool. However, the negative ends of both were indented from the pressure of such a tight fit. All three batteries were brand new Duracell alkaline with a 2016 expiration year.

What happened? And what is the proper way to install three (3) C cells in a 2-D Maglite? :thinking:

Thanks in advance.

 

[VidPro]

could be many things.
how severly did the spring or tailcap push into that last battery?
does the NEXT battery above that battery have any flaws in the insulation around it now?
When you shoved 3 into 2 , which is a cool trick, is there still a small divet thing in the switch area that sticks out a tiny bit in the battery tube?
and
why do they put mylar around batteries

 

[Mr Happy]

What happened?

What happened was probably this:

See the problem?

On an alkaline cell the whole outer casing right down to the base is part of the positive electrode. When you reversed the spring it probably pushed sideways and made a short circuit between the positive and negative parts of the battery casing.

 

[Let It Bleed]

Did a little more reading and see that I needed to cut off some of the spring. I should know that nothing good ever comes from forcing anything. I didn't want to mod anything so as to be able to easily switch back to D cells if I wanted. I'll just call it a "duh" moment and move on. While two of the batteries are probably fine, they are more than likely going to be tossed.

. . . is there still a small divet thing in the switch area that sticks out a tiny bit in the battery tube?

I hope not but I'm going to check, thanks.

At least I tried this in one of my older beat up Mags and not the nice unused one I plan to install the drop-in. Oh the halcyon days of 2-D Mags and AA Minimags. :sick2: Now that I know a little bit about flashlights, I want to get a 4-6 D Malkoff and use li-ions in a 2-D Mag. Who knew flashlights could be fun! And expensive!

 

[VidPro]

oops divot thing by switch does not apply, i was thinking 2D -3D not C
who would be crasy enough to http://www.candlepowerforums.com/vb/showthread.php?p=960315
nevermind that was a long time ago.

when i pulled out the switch to put more battery in, the screw divot was going to tear the insulation off the battery.

 

[novice]

Let It Bleed,
I read about this here recently and decided to give it a try, since I have a 2-D, 3-D, and 4-D maglite, and an old 4-C kel-lite and some extra C-cells.
I could get 5 C-cells in a 4-D Maglite, no problem. It took a little more effort to get 4-C cells in a 3-D Maglite. I couldn't even get 3 C-cells in my 2-D Maglite, and get the tailcap screwed in, but then I'm no longer in the flower of my physical youth. I know you don't really want to mod your 2-D cell Mag, but if you search on the web, I'll bet it wouldn't be too hard to find a source for Maglite springs, and they probably wouldn't cost too much. You could keep your original spring stock length, and work on gradually shortening your spare spring until it was just the right size, and just keep it handy. Swapping it out would only take seconds, if you needed to. Also, I found some short white plastic pipe sections at the hardware store that are a little shorter than C-cells, that the C-cells will go into, and that fit into a D-cell Maglite. I think they cost about .50? .25?, and they will keep your C-cells centered, and not rattling around too much when you do this conversion.
I haven't spent too much time in the battery section here, but I am enjoying Mr. Happy's communiques.

 

[Let It Bleed]

Good idea. I tried using a small spring I had laying around, but it was too small. I keep flip-flopping on just getting a 3-D Mag, but I don't like them. They are simply too unwieldly. At least with a 2-D, I can put it in a back pocket temporarily when needed.

 

[Kestrel]

IIRC, CPF member Conte (?) has done a few 'grunge' mag mods with pretty ingenious tailcap spring solutions. He has done a couple of threads with some good pics with regards to that.