Design ideas for a 2 18650 in parallel in 3c mag?

[smopoim86]

I'm putting a p7 in a 3c mag and would like to have 2 18650 in parallel. Anyone have any ideas on a battery holder to have them in parallel? I can do simple machine work, and any materials should be available. I was thinking of having a piece of pvc with metal caps on both ends and then jumper wires and separated tabs in the middle. Would that probably be my best option?

Thanks
Daniel

 

[Gunner12]

You can direct driver off of one 18650 but that would create more unused space.

The PVC tube idea could work. Just make sure the wires won't short to anything (obviously).

 

[nein166]

I had thought about this in a different light but...
Putting the 2 batteries (-) to (-) with a wire from the middle laying in a groove in the pvc sleeve. Then a (+) wire going from one end to the other. A plastic cap on one end (+) and contact plate on the outside for the middle wire to connect to.

This sounds like what your planning. Good way to get double runtime. I never came across a standard PVC diameter that fits in a C maglite.

Here's an illustration

edit: looking at this it might work better if the batteries could be side loaded

 

[2xTrinity]

In a 3C, you can get the same or more energy as 2p 18650s by simply using 3s NiMH C cells. The same if you go for low-self discharge cells 4500mAh cells from Thomas distributing. More if you go for standard 6Ah cells.

Another advantge of NiMH cells is that they can be safely series charged without balancing taps, so you could actually install a DC power jack up near the switch, and charge the NiMH cells IN the light.

 

[Norm]

You could use a disk made from double sided PC board for the centre contact.
Norm

 

[download]

Is this what you are talking about?
If you can reach some machine, it will be much easier.

 

[smopoim86]

In a 3C, you can get the same or more energy as 2p 18650s by simply using 3s NiMH C cells. The same if you go for low-self discharge cells 4500mAh cells from Thomas distributing. More if you go for standard 6Ah cells.

Another advantge of NiMH cells is that they can be safely series charged without balancing taps, so you could actually install a DC power jack up near the switch, and charge the NiMH cells IN the light.

I realize this, but would like to semi standardize my batteries. I don't really care if i have to take them out to charge them. Also, since batteries come in pairs, it's really more economical for me.

EDIT: I also dont have a decent charger for C cells. So it would cost me $100 to keep it C since i would get the maha 8 cell charger if i go that route. This solution is really temporary untill i can afford the c cells and charger i guess.

I have the tube and wireing, but need an idea on how to connect the ends. I'm thinking screwing caps of some kind or, like nein166 suggested, make it side load. The only thing i have against side load is that right now i have it 100% rattle free. I ended up machining it out of a piece of solid rod. I wasn't happy with the results of using pvc(batteries were loose and rattled to much for my liking.
Thanks