I had a couple of AAA lights I don't use much, more because I think the concept of using 3 batteries that only equal 1 AA in the space that fits an even large cell still is kinda dumb.
I bought the 21550 battery at meritline to resolve this but it turned out to be a fake. But it did get me thinking that a 14500 cell is about the right size for replacing the dreaded AAA. All you need is some 5/8" inner diameter tubing (preferably thick) cut to the right length, and the protected 14500 cells are exactly the same length as the adapter. This way you can get interesting aaa lights without using small batteries with limited current draw and capacity.
I also found 3/4" pvc of the right brand lets you use 18500's, but I don't really prefer them since it's a specialized size.
I bought a couple of the 3aaa lights before I knew any better, it drives me crazy now knowing how little capacity these three batteries have. I have ordered from Meritline a bunch of times and haven't got any junk yet so that's good to know about the 21500. Anyway this is a great idea I am going to try it out, thanks for sharing.
I did this with a 14500 and some inserts made from those styrofoam meat trays. Sadly, it was brighter if I put my tank007 m10 in the body in place of the battery, and skip the whole problem.
(you get a freaky green glow though, as the light is shining THROUGH the pcb and out the lcd enclosures)
You were never going to get 4.5v from the 3 aaa's anyway inline with a cree. Runtime with alkaline is also going to be attrocious regardless at anywhere near 1A draw (which it won't be). Maybe if they were enerloops you might be ok but then you have close to $10 worth of batteries that takes up 3 charger spaces on the light. Proper lithium DD w/ cree is going to be max brightness (for a bit anyway until output sags). It's about the best you can do w/ a DD light, which is why they used 3 cell in the first place.
This is also a proper budget mod, since the tubing is ~50cents a foot, which is enough for a bunch of lights. Plus you get to reused the 14500's.
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Someone asked for bit of clarification via PM, so copy/paste of my reply there:
I actually used clear plastic tubing. It's the soft stuff used to connect water plug available at any HW store. It's just a spacer to reduce rattle (the soft material helps) and prevent anything from shorting out. The way it works out is that you put the tubing in the light first, and then the 14500 can go in. 5/8 inner diameter is like 16mm (vs 14.5mm of battery), so there's going to be a bit of extra space.
What's wrong with a ~5cm length of 1 inch irrigation tubing? Cut to length, slit lengthwise and remove enough to allow it to close around the cell snugly without overlapping, done. Costs <<10 cents.
I got it at my local Ace Hardware. I don't see it listed on their website, but they probably all have it in the back room. What's great is they sell it by the foot, so you don't have to buy several lifetimes worth.
i use an 18500 and section of sleeve for a t5 fluorescent tube.while the 14500 is less than 3 good nimh it still is nice to have another option in an emergency.
note that some 3aaa lights burn up with good li-ion due to lack of sag.yes they will run brighter if they dont melt down.