What to do with used AA cells?

shiftd

Flashlight Enthusiast
Joined
Nov 17, 2002
Messages
2,261
Location
CA
Spend them!
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Here is how:


First, you need a AAA to AA upsizer like this

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Then you will need to put joule thief circuit inside the battery adapter.
Search google for joule thief, and I am sure you will get more than one hits
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It is a simple way to drain your battery silly.

Next, after you put the joulethief inside the adapter, you will end up with something like this
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I added switch inside the adapter. The reason of that, I will explain later

Now, you will need 4AA to D adapter like this (same thing with the one from robspook GB). 2AA battery pack would work also.

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And last ingredient, of course, none other than the spent cell itself:

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Once you have all of those ready, put them together and you will have something like this:

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Woot, what do you have there. Small night light that is good for those small trips in the middle of the nights. You can also use this as an ambient light on the side of the bed.

The reason I recommend 4AA to D adapter is because with the additional cell, you will have extra capacity, meaning longer runtime. Beside, the light is very stable because the D form factor has a low center of gravity, so you can practically place it on almost any flat horizontal surface.

The switch is there for convenience reason. If you want to use the light solely for those visits to the bathroom in the middle of the night, having a switch to turn on/off the light is much better than having to remove the light every time you want to turn it off.

The brightness is on par to original CMG infinity. It actually depends on the led you used.
Instead of a joule thief, you can also put high power led on aluminum heatsink on the AAA to AA adapter. Using low power converter (50 mA) to the led, and you will have a nice one directional area lighting
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Let me know what you think
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true that

However, eternalight has the batteries wired in series. If one cell got emptied before the rest, it might get reverse charged and leak. You dont want a leak in your eternalight, do you?

Also, you can use your eternalight for other more useful uses instead of a battery sucker.
 
I found the 1AA 1 Watt light from Lowes (Task force?) can suck a AA pretty low. I use one as a night liight. If can also get a 4AA battery holder and wire a few in series and connect it to a light with a boost circui to use 3 dead AAs to power a 2AA light or 2AAs to power a AA light or even 4AAs for a 3AA light.
 
Arc LS will even suck a dry cell dry :)

But still, great efforts on the mod !!
 
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