Are there longer batteries than the 18650?

[CPFBiology]

I tried searching the forums, but no luck.

Does anyone know if there are batteries out there longer than an 18650?

in particular one that is three C123a cells long, equivalent to two 18500's?

Really, what I am looking for is something that is long lasting that delivers 3.7V for a Surefire 9P body and Malkoff M61 for longer run time. Or is the MD4/Surefire 9P + A19 extender the only other way to go? (2x18650)?

 

[VidPro]

3x 123 / 2 = 50-0? no?
so if it uses 3x 123 , and handles 9V could you do 2X50 or 18500?
measure guess measure, quickly i get ~33-34mm for a primary 123, then figure ~100mm for 3, then 1/2 would be 50mm. so that still leaves some space for protection on a 18500 even, to actually safely pull it off.

 

[shark_za]

2x 18650 is a long lasting option but you say ideal is 3.7v not 7.4v.
I know of nothing in a single cell that long.

Run a single 18650 with a spacer or 2x18500 if you can do 7.4v.

 

[Kraid]

Run a single 18650 with a spacer

I think thats your best bet. AW sells them. Or at least the last time I checked he did.

 

[fivemega]

Really, what I am looking for is something that is long lasting that delivers 3.7V for a Surefire 9P body and Malkoff M61 for longer run time. Or is the MD4/Surefire 9P + A19 extender the only other way to go? (2x18650)?

Why does it have to be 3.7 volt battery while mentioned drop in will take up to 9 volts?
2 of 17500 cells will fit stock 9P perfectly.
BTW, only bored out 9P body will accept 2x18500 cells.
Next choice is 9P + A19 extender with 2x17670
Bored out 9P + bored out A19 extender with 2x18650 will run much longer.
If you still need longer run time, oversized aftermarket bodies are available.

 

[Kestrel]

There was a wish-thread for something like an "18990", you will find some discussion of that here.