2/3rd batteries?? Hold it Tim!

[dfischer]

Like, Oh My God!! (sorry I couldn't help myself. Too bad there are no valley girl smilies). Anyway:

2/3rd batteries, be they in a "C" (think lowes) or a DX AA light, means we could get the voltage of 3 cells with the convenience of standard size batteries for emergencies. I may be in love.

Are these things practical?

Does anybody make a 2/3 C or AA in an LSD?

What am I missing? This should be HOT and nobodies talking about it (which usually means I'm missing something important)...

Who makes a charger that accepts them?

 

[DM51]

You will find answers to such questions in the Batteries sub-forum, so I'll move your thread there.

 

[dfischer]

Yes, this is getting lots more response.

 

[mdocod]

We do use some "odd size" cells in certain flashlight builds.

tri-bored mags loaded with 2/3A size cells are common for getting a lot of juice into a small place.

There are lots of various odd-ball size cells out there, most in NIMH and NICD chemistries, like 2/3AA, 1/2AA, 1/3AA, 4/5Sub-C, sub-C, 4/5A, 4/3A, A, F, 1/2D.

You COULD use a set of say, 3 2/3AA cells in the space of 2AA cells, but this is not always practical:

1. You can make good use of the 2 cells with a boost driver anyways.
2. AA size cells are available in the ~2000-2700mAH capacity range, whereas 2/3AA cells don't really come any higher than about 700mA, so 2 AA cells have more useful watt-hours of juice, even with a less efficient boost regulated setup for an LED.


So when trying to figure out how to utilize a less-standard cell size, most people do so with the intention of maximizing available power or energy in a certain space. 2/3A cells are popular for this type of setup because there has been a LOT of focus on 2/3A size cells as a result of the radio-controlled community. They are popular cells for road-track racing cars. So they have been developed up to ~1500mAH and capable of major drain rates like 20-30+ amps (depending on brand), not bad for their small size.

I'm not really sure if that helps answer the question or not,.... let me know.

Eric

 

[Fallingwater]

Cheap drivers have long made the need for an exact number of cells obsolete.
2/3 cells (rechargeables only, of course) could only be useful if you wanted to retrofit a LED to an existing 2D/2C light without bothering with a driver, and that assuming no size mismatches (the terminals might make 3 2/3 cells a bit longer than two normal ones). You'd still need a resistor somewhere in the circuit though.

Other than that, powerful non-EDC flashaholic-level lights normally use 18650 LiIon cells, and with good reason.

 

[DM51]

Yes, this is getting lots more response.

Very funny, I'm sure. If you had read through the lines of my post, you would have realised it was a polite way of saying you had posted in the wrong forum, and you should go take a look in the right one (which is now here, where I moved your thread).

Sometimes it pays to look up existing posts instead of immediately asking a question. There is a great deal of information available. However - you are now getting replies, so you should now be satisfied.

 

[dfischer]

Mdocod:
Thank you kind sir. I've looked around quite a bit and your point #2 re mah density seems, quite sadly, to be the case. Rats. But thanks for the advice.

Mdocod and Falling:
The reading and inquiry's I've made seem to suggest drivers, or at least the ones coming std in most lights, will boost and regulate, but they seem also to current limit for a given voltage. So, a 3.6V input battery array would be driven to say 3.7V @ 8a, while a 2.4V input might be boosted to the same 3.7V, but @ a vastly reduced current level. And so reduced light output. Or so goes my present understanding (however limited),

The thought however briefly it lived, was to be able to see reasonble run-times and increased light outout vis a vie the higher starting voltage. All all with the ability to still run gas station available size batteries as a backup.

Ah well, it was a thought...

Falling: Yes, I see a large following for the 18650 and won't disagree. It doesn't fit my "gas station" model and so isn't for me, but it IS a nice format. Actually, I'm surprised there aren't lots of lights that parallel 2 of them by design. It would seem to be a natural and more efficient. Course there may be lots and I've missed it. I am kinda looking a aa and c formats....

DM51:

I seem to find irony and situational comments funnier then you. Or at least you felt it was at your expense instead of a comment about the situation as a whole. Not intended AT YOU, just an observation that I sorta thought wouldn't take explanation. But.. see, it is a rather lower traffic forum right? So the move DID get fewer observations. And the candlelight smiley, IS sorta analgous to "anybody home?". Well, it seemed funney to me anyway. (shrug)

Course you were also correct, which is why I didn't #$% about it, I just made my little wise-*** humor remark and moved on. Never crossed my mind you'd take it personally. Sorry.

You mean search is my friend? And some of these have been mentioned just three lines below...

Ah no, I'd best stop and not do another captain obvious comment or we'll just start over. However, I would mention I find this site, for some inexplicable reason, to be rather fraught with search problems. There are lots of times I kinda wonder if searches make this site a bit fragile. Lord knows I've had lots of lockups and server not found errors after pursuing searches here.

Don't get the wrong idea. Fragile or not it's still the best site around. But experience suggests searching may be MY friend, maybe not so much for your host.

But again I digress. Nobody ever said being a mod was easy, and if you felt my little funny was too much at your expense, why again please accept my apologies.

 

[DM51]

I'd best stop

Yes, I think you'd better, or you'll find that baiting a moderator is not really a very good idea.