Krypton/lithium mod of a $5 AA

My goal was to take a cheap AA flashlight and make it more useful by drilling it out to take 3 CR123 cells and then swap out the bulb for a brighter 7.2 volt Krypton. I chose a $5 Rayovac at Wal-Mart because it had a body big enough for the larger lithium cells. Then I took a 43/64" drill and ground the tip flat. I found that I needed a drill bushing to guide the drill, so I made one of those. That's it on the drill in the pic. The drill left a bunch of polymer "fringe" which I tried to clean off using a hobby knife. The bulb came from Radio Shack and costs about $1. It's 7.2v and 0.7 amp. It's a standard 6 cell bulb. The light output was much greater and much more useful than the original with AA's. I don't have a way of measuring the lumens but I would guess it's probably in the 8-15 lumen range. Which is what I was looking for since I'll use the light to work inside dark machine cabinets. My only disappointment was the life of the batteries. Again I can only estimate but I would say they had a run time of about 20-30 mins. Maybe less. The Surefire batteries seemed to run longer than the Radio Shack ones I started with. Any ideas on how to get longer battery life? I don't know enough about LED's to build one of those to fit yet. Is there a different bulb out there or could there be something about the flashlight circuitry that could be wasting power? I welcome any and all ideas. Again my goal is to produce about 15 lumens of light for close up work in dark machine/electrical cabinets.

Here's two more suggestions, both rechargeable and with a non-bored out AA light:

1) 2 x 14500 from DX/KD/QCG etc, with a Magstar Krypton LWSA601 or Xenon LMSA601 bulb

2) 2 x 14500 from AW, with a Pelican 3853L or 3804 bulb

Both of these will be much brighter than your existing setup. Note that the 3853L in particular will gradually melt the reflector.

Last but not least, you can venture into hotwire territory with the AW 14500 cells by using the Pelican 3854L bulb.

lctorana said:

Here's two more suggestions, both rechargeable and with a non-bored out AA light:

1) 2 x 14500 from DX/KD/QCG etc, with a Magstar Krypton LWSA601 or Xenon LMSA601 bulb

2) 2 x 14500 from AW, with a Pelican 3853L or 3804 bulb

Both of these will be much brighter than your existing setup. Note that the 3853L in particular will gradually melt the reflector.

Last but not least, you can venture into hotwire territory with the AW 14500 cells by using the Pelican 3854L bulb.

Click to expand...

Great! I didn't realize there was a rechargeable Li-Ion AA size cell. As a newbie though I have to ask what the abbreviations DX/KD/QCG and AW mean? Sorry.

DX is dealextreme.com. KD is kaidomain.com and I'm still new, also, so not sure about the QCG. Hope that helps

"Quality China Goods". All four are registered and active on CPF.

My point is that there are two classes of protected 14500 cells.

The cheap ones will not light up the higher-current bulbs (partly because their ptrotection circuits are too aggressive).

But you can get away with them for Maglite bulbs.

if 8-15 lumens are all you want, then isn't your Rayovac in stock form sufficient? just use nimh's for the battery problem and maybe frost the bulb to clean up its beam.

To lctorana & revs:

Thank you. I haven't found all the resources on CPF yet. It looks like I have a lot of reading to do.

To rala:

Maybe I've understated what I needed. The light as original with its 0.88 watt bulb was much too dim to use. In fact I would have considered it unsafe as a power outage flashlight. Don't put too much faith in my lumens estimates. I read somewhere that 15 lumens makes a nice light for up close work. I really don't know what 15 lumens looks like. And, I don't think my photo above does justice to the light output of the modified Rayovac. Thank you for the frosting idea. I suppose there are instructions here on CPF on how to do that? I'll have to do a search.