high current 2P 26650 carrier for Mag 2D

[Techjunkie]

As a stop-gap solution to direct drive an SST-90 to 9A until a suitable 9A CC buck driver becomes available, I've slapped this high current 2P 26650 carrier together. Built from Aluminum duct sheet metal and aluminum rivets, it aint pretty, but it will do for now. Plain, two sided PCB with the copper removed from the edges and a lot of epoxy holds the interlocking chambers together while electrically isolating them from one another. The top of the bottom one contacts the bottom of the top battery and vice-versa. Battery contact "springs" are made from a single fold of sheet metal, just like in many battery carriers that don't use springs. Electrical tape insulates the sharp Aluminum sheet metal from skinning the batteries and shorting the positive segments against the negative metal battery cans. The tailspring is built in (riveted) to make contact with the inside of a 2D Mag's tailcap with the anodizing removed. Packing wrap surrounds the loaded assembly before it enters the tube. I tried making channels in a C-D PVC tube but couldn't manage it with the tools on hand. My 4500K SST-90 emitter comes in a few days. Hopefully, this will reduce battery sag and allow for decent run time at or near 9A.

 

[Ajay]

it aint pretty, but it will do for now.

No kidding:nana:

But I like your ingenuity, nice work. I hope those are protected cells

 

[Linger]

hey, well done.

 

[Lumencraft (Matt)]

Hi Teckjunkie,

Neat idea, I like that the rear contact spring is a part of the adapter rather than part of the light. What/where are those cells from?

 

[Techjunkie]

Hi Teckjunkie,

Neat idea, I like that the rear contact spring is a part of the adapter rather than part of the light. What/where are those cells from?

Those are Sony 26650VT LiNiCoMn cells from a tool pack. I bought 8 of them loose on eBay. They're capable of 50A current discharge. Check out Lux's safe Li chemistry thread, they're covered pretty well in there.

 

[Al Combs]

it aint pretty, but it will do for now.

I disagree, functional is beautiful. It's a good mod. :twothumbs

 

[Techjunkie]

I took this for a quick run tonight after assembling my SST-90 and after being underwhelmed, I discovered that the tail spring adds too much resistance. I had to reinforce it with copper braid. 8 amp draw with braid, only 3.something amps on spring alone. I'll be starting a thread for the finished torch later or tomorrow.

 

[kramer5150]

thats so ingenious!! I was banging my head against the wall trying to figure this one out... I just gave up. I want to do a direct drive P7 setup from a 2P-26650 arrangement.

thanks for sharing:thumbsup:

 

[supasizefries]

Very very nice. I have a sst-90 laying around as well, been trying to figure out power options.

 

[Techjunkie]

Thread to the torch that I'm using this contraption is has been posted here.

What I've discovered so far is that the spring I used adds significant resistance. It probably would have worked better if I had filed off the coating on each end before riveting it to the bottom of the "carrier". That plating just can't handle the load. After I shorted it with copper braid, my tailcap measurements shot up from 3+A - 7+A.

I also tried NiMH C cells. Three slightly used cells drove the emitter to 5-6A, and with four of them, draw shot up to 11A before I disconnected the leads a split second later. My next direct drive experiment with this torch will probably a 4s2p pack of NiMH AA. I'm hoping that 2p AAs sags a bit more than 1 NiMH C does. I'll start with Duraloops and then move up to Titanium 1800s or down to lesser AAs to try to find the sweet spot where internal battery resistance regulates the emitter to just ~9A current draw.