Question about parallel battery configuration

AlexGT

Flashlight Enthusiast
Joined
Jan 15, 2001
Messages
3,651
Location
Houston, Texas
Hi all!

I was thinking in doing a PWM DD P7 mod using a 2 li-ions in parallel on a FM11 and have some questions

I plan to connect the batteries like this,

parallelbatteryconfigurdi5.jpg


The insulator will be a piece of PCB board, and wrapped in shrinktube, Any tips? Has it been done before, what kind of wires do you recommend, the current for the P7 will be between 3 and 3.5 amps depending on the Vf of the led ( Photonfanatic says he might get P7's in DXXXI or DXXXH!!!)

Thanks!
AlexGT
 

LukeA

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Jun 3, 2007
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near Pittsburgh
24ga is the minimum recommended wire size. You might consider using desoldering braid because of its low profile and low resistance. Just make sure to isolate it from the inside of the battery tube.
 

AlexGT

Flashlight Enthusiast
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Jan 15, 2001
Messages
3,651
Location
Houston, Texas
Thanks for the tips Luke!, I like the idea of desoldering braid, will post pics when done.

AlexGT
 

Aircraft800

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Apr 24, 2007
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1,487
Location
DFW Texas.
Is there really room beside the cells to use 24ga wire? Would you have to cut a groove in the tube to accommodate the extra wire?

Another idea is to use the battery ribbon like used in the Stinger packs (it brings the negative terminal up to the top of the light) and get some heat shrink. I've disassembled a few packs to rob the Li-Ion batteries that had this type of setup, Teflon type spacers between the cells and thin ribbon connecting everything. Perhaps LuxLuthor would know where you can get the materials since he used to build so many different packs.

Good luck, I'd love to see what you come up with!

FYI:
There is a Quality buck driver out now that would fit a C Mag

Shark Buck by the Sandwich Shoppe
https://www.candlepowerforums.com/threads/211599

or the Der Wichtel, but only for D Mags

SSC P7 Buck Converter by Der Wichtel
https://www.candlepowerforums.com/threads/201981
 
Last edited:

AlexGT

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Joined
Jan 15, 2001
Messages
3,651
Location
Houston, Texas
Ok I'm done, wasn't as hard as I tought it would be.

I used desoldering braid to make the connections, I soldered the pieces like in the drawing, used a bit of sandpaper to rough up the surface, I also used a very hot soldering gun to make the solder as fluid as possible.

I had to ditch the heatshrink because it didn't fit the FM11 tube, I used regular electrical tape to insulate the soldering braid, since the FM11 has a charging port I don't need to take the batterypack out to charge it, so electrical tape seems fine for now.

Now I am waiting for Photonfanatic to come up with the D P7's and to select a good driver either a D2dim or a triflupic.

I'll keep you all informed, thanks helping me.

AlexGT
 
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