Multi cell battery vampire wanted

In my family we have many portable devices, kids toys, cameras etc etc. and as a result we have dozens and dozens of partially used AA cells,

can i buy an adaptor for a mag light 8xAA or 12xAA or something, and run an led until the cells are 98% depleted?

im aware of some potential issues with cells at different levels of discharge and pulling high current, which is why im thinking about lower current.

perhaps a 2 x D mag with an adapter for 8 AA cells (of unknown state) providing 60 or 80 lumens via a led mag replacement led bulb ?

would this arrangement drain all the AA cells equally ?

any thoughts

would this work in a 2xD mag?

http://theledguy.chainreactionweb.c...d=778&osCsid=f002a74a021958849a270b5ac19a72cb


http://www.batteryjunction.com/tle-1f.html
:thinking:

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Running multi cells in a vampire mode could be an explosive experience .


or it could be a real BLAST !

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If you are talking about plain old alkaline AA batteries, I don't believe there would be any explosive danger. Leakage if you forget about them, sure, but I feel there is no danger of .

Any light without boost regulation (circuitry that increases voltage by drawing higher current) should work to drain them all the way. Somewhere on the board a member listed which lights have boost/buck regulation.

I believe there would be some equalization taking place but as long as you're using alkalines, and they're reasonably close to each other in remaining energy, I wouldn't worry about it. All that happens with mismatched cells is the stronger one charges the weaker one. They sell alkaline chargers specifically meant for charging non-rechargeable alkalines.

Wattnot said:

If you are talking about plain old alkaline AA batteries, I don't believe there would be any explosive danger. Leakage if you forget about them, sure, but I feel there is no danger of .

Click to expand...

You've not heard ? ... of multiple AA cells ... Gassing and expanding the rubber button boot till it looks like a small balloon ?

Strange things happen with ALL multi-cell applications.

Ya just never know .... batteries are small containers of compressed , expansive energy ..... coiled and ready just like a rattlesnake .... to bite ya in thu butt !

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( Don't pay any attention to me .............. I'm just feelin PARANOID )

Never had AA's do that. Seen pics and heard people claim it's happened but so far so good here.

Note that I've only been eeking the last bit of juice from multiple cell AA lights for 30 years. Maybe I'm very very very lucky to of only seen leaks from the practice. Hey maybe it's because my lights aren't rigged for operating at the sea floor! Air tight isn't always a good thing.

Just use 2AA mag as a candle until the light when out.

I made my own 2-4 cell battery drainer using a 4AA cheap plastic battery holder, a variable resistor, and the guts out of a broken 3AAA luxeon headlamp. I even wired a 5mm white LED in parallel to it. I have it lighting up my keyboard on my computer and my lcd temp/clock sitting next to the computer. It will put out some light using 2 slightly drained ~1.3-~1.4v AAs but I tend to use 3-4 cells and crank the resistor for the light level I want. I have a battery leak once in awhile but I just clean it up and sand the springs/contacts if needed. I don't overall recommend draining multiple cells in good lights unattended for days because if you forget and drain them completely leakage chances increases dramatically vs the days when incans would kill a battery to 1v and you tossed it draining them to 0.3v in series you will at times reverse one. I had a AAA reverse to almost 1v and put it in a dorcy 1AAA led and it lit it up backwards for a second then dimmed to nothing.

This is probably a stupid question, but why is it necessary to drain the batteries completely? Is this for rechargables?

MikeyT said:

This is probably a stupid question, but why is it necessary to drain the batteries completely? Is this for rechargables?

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some devices/lights stop working at voltages of 1.2v which will run an LED at useable levels for hours, even days. You could throw them away but people like using every bit of energy before tossing them. Instead of buying more batteries for lights you use often you just reuse these batteries in lights that have lower output levels. Some lights can drain that 1.2v battery down to 0.4v before giving up. I have lit my keyboard up on my computer for a week off used cells.

Hi:

I have a couple of Willie Hunt's regulated 8aa>2d battery holders which use pwm to regulate voltage at 3.6 and have an FET that limits current to 2.0 A. Even better, these adapters have a soft start.

See this thread. https://www.candlepowerforums.com/threads/65593

I have a large and durable supply of Ray-o-Vac 1800 rechargeable NimH AA's that are thin enough to fit into these adapters and slip into an unmodified Mag 2d body. I usually use these to overdrive a stock Mag 2D krypton bulb -- doable without instaflash only because of the soft start. This device could also be loaded with 8 @ alkalines as a vampire for a 3.6V bulb.

The fun will actually begin for me when the Cree XM emitter comes out rated at 750 lumen at 2.0 A at a vf of around 3.6V. I expect to set up a direct drive XM emitter in a Mag 2D and simply power the light with Willie's 8aa>2D regulated adapter.

Some voltage regulated multi AA cell holders may still be available. These adapters were priced at $20@ when they were available.

I use a nite-ize Minimag LED dropin that $5 3-emitter job to finish off cells. I dont care if they leak... its a $8 light.

Yeah, that Nite-Ize 3-LED drop-in will drain 2 batteries down to the point where they definitely will leak. I use it in a cut-down Mini-Mag 1AA and it works just fine down to 0.7V! I cut that light down because I was getting tired of leaking cells, which you get from using two cells and draining them down this far. It doesn't matter if the cells have been used together from the package, you will always get an imbalance between them and, invariably, one will leak.

kramer5150 said:

I use a nite-ize Minimag LED dropin that $5 3-emitter job to finish off cells. I dont care if they leak... its a $8 light.

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I bought one of those dropins a few years ago for a minimag. At the time, I thought I was buying a real improvement. Don't get me wrong the runtime is impressive, just not very bright whatsoever. It will drain your already used batteries, that's for sure.

JonN06 said:

I bought one of those dropins a few years ago for a minimag. At the time, I thought I was buying a real improvement. Don't get me wrong the runtime is impressive, just not very bright whatsoever. It will drain your already used batteries, that's for sure.

Click to expand...

still a useful dropin for emergency lighting but only if you have a spare 2AA incan maglight otherwise save your money and buy a 2AA magled when they are on sale probably black friday.

thanks for the ideas all, it just seems 'wasteful' to have all these partially drained AAs laying around, i dont like waste.

i guess ill buy 5 or more single cell vampires

https://www.candlepowerforums.com/threads/185691



and leave them all over the house