Modding DX 8-LED 1-AA light

I got this flashlight (among some others) on DX.
It's nice, but it has a bluish and not terribly bright output, which tells me it doesn't use the newer 20.000 mcd LEDs.
I recently got a bag of 50 20.000 mcd LEDs on eBay. Here's a beamshot comparison between the 8-led light and a single 20kmcd LED running off my lab power supply (25 ma):



Of course, the first thought that crossed my mind was to mod the light with the better LEDs.
Problem is, I've no idea how to open it. The outer metal ring feels *very* solid. On the other hand, the electronic board doesn't seem extractable from the battery side, because the screw threads make the passage too thin for it.

Any ideas?

I have a few of these, I actually really like them, for the price they're a great light and have a good battery runtime. I've also wondered about modding them with brighter LEDs, haven't tried it though. I think the bezel is pressed in, maybe freeze (or boil if it's glued in) the light and try to pry it off. BTW, they do vary alot in color temp, I have one that's very blue, a couple that are pretty neutral, and even 1 or 2 that seem fairly warm in color.

Really stupid question BTW, are the brighter 5mm LEDs like you mention more efficient for a given brightness vs. the dimmer 5mm LEDs, or do they simply handle higher current (and brighter because of the higher current)? I take it that they actually are more efficient and therefore brighter and that the circuit supplies the same amount of current regardless of the LEDs.

They are more efficient.
I got two of these for my girlfriend, and the first I noticed when I turned them on was the craptacular quality of the LEDs. They were *very* blue, and very dim (one had the left LED way offcenter and dimmer).
I opened one up, tossed the LEDs, put two of the 20kmcd in their place and the light's beam is now considerably brighter and more pleasant.
(still less bright than these that only have one LED, but I assume that's because the pigs use different, less powerful cells that can't deliver quite enough milliamps as the two CR2025 of the white keyring lights).

Thanks for the idea, I'll try to heat the metal ring.

I have a similar light that developed problems. Could not see any way to access it from the back. Finally I decided I was either going to open it or destroy it; it was already broken after all. I attacked that front crome part with a chisel and it came off with only a small nick. It was press fit and after I made a few fixes to the PC board it pressed back into place with no problems.

Try working it loose by tapping or prying one side and then the opposite alternating back and forth. Good luck!

Bloody thing is so tightly pressed on there is no space to stick anything between it and the metal behind it.
I tried heating it with a flame and pulling with pliers, and all I accomplished was to nick it.
ARGH!
I'll try heating it some more, if it doesn't give it goes in the bench vise.

There are several versions of the 8-led 1-AA flashlight. Mine, too, are the push ins. Yes the metal ring/disk is VERY solid and yes it will need to go in the bench vise. Clamp the disk so that the flashlight is horizontal. It will need to be very tight and will damage the disk. Most of the damage can be removed with a little delicate filework! Now pull the body of the flashlight, while at the same time trying to waggle it from side to side. It's the waggling from side to side which appears to do the trick!

John L

If you like the basic concept of this light, here's another one that's basically the same except with 5 LEDs instead of 8 and the bezel should be easier to get off because there are ridges behind the bezel that would make it easy to get a tool under to pop the bezel off.
https://www.kaidomain.com//WEBUI/ProductDetail.aspx?TranID=2147
A possible issue would be that since it doesn't have a removable head like the 8 LED version, I don't know if that would make it any harder to mod - hopefully everything can be pressed out from behind the circuit board. The beam is about the same, slightly less bright than the 8 LED version but then I suspect less current is being drained from the cell. It's a cosmetic knockoff of the Inova X5. One thing better about the 5 LED version, it fits better in a pants pocket since it doesn't have the wider head like the 8 LED version. I may buy another one of these 5 LED lights and try getting the head off, I'll post back if I ever try it.

One thing that I would recommend doing would be to add one red LED (with appropriate series-resistance to account for the lower forward-voltage of the red LED) into the mix. White LEDs are usually deficient in red output, so mixing a red LED in would radically improve the color rendering of the light.

Mine was that bad I gave it away soon as I got it

Back in March I ordered 6 of those lights from DX. Only one of them was the dimmer blue output, the other 5 were very nice with a much warmer and brighter beam. Since the dim blue one also had a rotten O-ring, I assumed it was from an older batch or a different distributor.
When did you get yours?
At this price and since it's hard to get into, it might be worth it to order a few more but I know the waiting and the gamble is a pain.
At any rate, there are good ones available without having to break into that stubborn bezel ring.

The 5-led light feels like it'd fail to meet the minimum brightness requirements.

2xTrinity said:

One thing that I would recommend doing would be to add one red LED (with appropriate series-resistance to account for the lower forward-voltage of the red LED) into the mix. White LEDs are usually deficient in red output, so mixing a red LED in would radically improve the color rendering of the light.

Click to expand...

Nah, the 20000mcd LEDs I have are pretty darn white. Adding a red LED would probably just make the light reddish.

RebelXTNC said:

Since the dim blue one also had a rotten O-ring, I assumed it was from an older batch or a different distributor.
When did you get yours?

Click to expand...

Not a month ago.
The o-ring seems fine though...

At any rate, there are good ones available without having to break into that stubborn bezel ring.

Click to expand...

Meh. I care not for the aesthetics of flashlights, so a ruined ring is not a problem for me as long as it holds the light's giblets inside.

I am consistently failing to get it off, by the way. I can't find my bench vise, and pliers didn't do the job.
I dremeled a bit of the black metal off from behind it, and tried attacking it with tongs (no, not thongs). I inserted the tongs' mandibles in the ridges I carved, pulled as hard as I could, and nothing happened.
I tried inserting a flat screwdriver blade in the ridges and hammering outward, and still nothing.

There is always the final solution, which is to dremel the whole ring off and to glue it back on when the modding's done, but it's really quite inelegant... let's hope I can find my bench vise before I lose my patience.

Try the freeze pop method on it. I found a place locally selling the 2AA 8LED lights (Xnovas) for about $2 each and I used the method to extract the guts from it. I found the 2AA version considerably brighter than the cheaper version of the 1AA probably due to being underdriven more. I have a 12 LED 1AA light the battery goes in backwards that is considerably brigher than the normal 1AA and almost as bright as the 2AA versions.

So I basically just throw it in the freezer for a few hours and then try the tongs again?

The freeze pop method is to put the empty(no battery) light underwater and screw the cap on underwater, making sure that there is no air bubble. Then putting the light in the freezer. The expanding water should push the innards out of the light. It mike take a few tries to get the whole thing out.

The 8-led light only has one o-ring. If I do that, I'm pretty sure all the water would get out before it froze.
I'm not sure it'd be a great idea anyway, because it has a converter. Water will probably not damage bare LEDs, but the electronics in the converter... i'm not so sure.

It usually takes 2-3 sessions of freezing to get the lights apart. I put the one I did tail end down to prevent leakage through the head of the light. The light I tried it with had a plastic spacer between the circuit board and LED module which helped protect from damage, not sure if all are built that way.

Nah, the 20000mcd LEDs I have are pretty darn white. Adding a red LED would probably just make the light reddish.

Click to expand...

Even LEDs that look perfectly white by themselves are weak in red output, that's becuase they are essentially a blue emitter with a yellow/green phosphor layer. Very little red is emitted, which makes reddish things like wood and skin tones look unrealistically pale. Try turning on a bunch of white LEDs, then get a single red photon or something and add that into the mix. A tiny amount of extra red (say one LED for seven white LEDs, all driven similarly) will make a big difference. Even my "warmest", whitest Cree LEDs (better tint than any 5mm LEDs I've ever seen) are improved by adding red into the mix. The beam does looks uglier on a white wall (more reddish) but real-world color rendering (ie wood, skin, trees, etc) is improved.