Has anybody ever hacked a LIR2032 cell in a Photon?

Photons and such micro-lights are usually powered by two CR2016 cells of miserable capacity, giving approximately 3 volts between them.

What if one were to discard the two CR2016 and insert a single 3.6v LIR2032 LiIon button cell?
2032s have the exact width of two stacked 2016s, so it should be a drop-in replacement.

Cheap unregulated clones would require a resistor inbetween the cell and the LED, so some hacking would be required, but microcontroller-regulated Photons (and clones, if they exist) should be able to deal with the slightly higher voltage of a LiIon.

A LIR2032 has about 40 mah, so it should power a Photon for about a hour and a half at full brightness.

Sounds like a good idea to me...

Have you tried a standard 2032 battery in it to see if it even works with it?
Some microprocessor circuits require 4-5v to operate properly.

Hmm. Had a look at CR2016 specs, and they have a three volt output, not 1.5 as I first thought.
Well, this puts the whole theory to rest.

It brings up a question, though: how do unregulated lights work without blowing the LED? It's getting about six volts for at least a moment before the cells sag...

You know, you can use rechargeable LiIon 2032 batteries. I have 4 photon freedoms that I run that way. That includes white, cyan, red, and yellow. They all work just fine. Runtime is not very good, however, and unless you really need fine dimming control for nightvision, I would look at other options (like AAA).

EDIT: I should have added that you need to make sure you don't run the batteries down too far. I've lost a few that way.

Try a search with " 2016 2032" . You will see that the idea is not new.

With a 2032 on a fauxton the light is dimmer but quite usable and the run time is very long.

What is the point in 2032 rechargeables in such a small light - when the primaries cost next-to-nothing and have greater capacity?

The primaries only have greater capacity under a very light load.
CR20xx cells are meant to be used in clocks, as memory backups and the like. They are NOT meant to deliver 20-30ma, and their voltage will quickly sag if they have to.
Keychain lights run on full power for the first few minutes, then spend most of their life running off severely drained cells, drawing considerably less current.

A LIR2032 LiIon cell should have little trouble delivering 20-30ma, and would do it for most of its charge, so you'd end up with a photon running on full power all the time.

Of course, you'd need to find room for two cells... for some reason I thought 2016 cells only gave 1.5 volts, when in fact they give double that, so the idea pretty much goes out of the window.

I had tried it with my Photon, nothing much happened

I've just taken some measurements on my cheapo DX keychain.
On two fresh CR2016 the voltage drops to less than four volts, and the LED gets 60 to 70 ma!!
That's a brutal overdrive! It's a good thing the cells sag quickly, because I don't see a 5mm LED surviving that sort of treatment for long...

Do you know of any place that sells LIR2032s in Europe (Italy) without charging more than forty dollars for shipping (*cough*batteryspace*cough*)?

I want to try using a LIR2032 with a resistor in a cheapo-light... should work fine if I manage to do it without destroying the whole thing

I thought of the same idea of a li-ion 2032 in a keychain light but after I found places online selling 2016 for about $4 shipped for 20 pcs I said forget it and bought a tray of them at about 40 cents per light for replacement batteries once a year is negligable compared to having to recharge them. I typically don't use 2016 keychain lights much now I have an arc clone on my keychain and a uk 2AAA eled in my other pocket.

I don't want a rechargeable microlight because I'm scared of the price of replacement cells. I know they are dirt cheap.
I want it because I don't like having a light that runs at full power for a few minutes, then spends most of its life running at reduced power from the trickle of charge left in the button cells.
I want it to run at full power all the time.

i also tested the voltage and current in a dx keyhain light on 2 2016's. i got 4v and 80ma. then i realised that 80ma is perfect for the 4-die SMJled, so i put that in and now its a very nice little SMJled micro light. runtime is probably horrible but the led will last a long time.

What's a SMJled?

Fallingwater said:

It brings up a question, though: how do unregulated lights work without blowing the LED? It's getting about six volts for at least a moment before the cells sag...

Click to expand...

probably same as why 9V transistor batteries don't blow 3V LEDs...amperage is too low to have any wattage

Fallingwater said:

What's a SMJled?

Click to expand...

link: http://theledguy.chainreactionweb.com/advanced_search_result.php?keywords=smj&osCsid=7cd49006972bdfecef76a528c184c9bf&x=0&y=0

it looks just like a 5mm white led but it actually has 4 dice instead of 1. it takes 4 times the current that a normal 5mm led would.

i was initially disapointed by the output because it didnt have any more throw than some leds i got from ebay (jled's brightest 5mm leds) but soon i realised it had a much much wider beam and the same throw, ie. alot more light.

i prefer it to any regular 5mm led but at $5 apiece its hardly worth it. im glad to have 1 for my edc micro light, but 1 is enough. for that price you can get a cree or rebel. btw has anyone gotten a rebel into a microlight?

Waaahhhh!!! Expensive!!

Standard 2032 works fine, but it is noticeably dimmer. It will keep that same brightness for much longer though. Seems like the 2032 would be better if you were using it often. Otherwise the bright but shortlived 2016s would probably be appreciated.

Fallingwater said:

I don't want a rechargeable microlight because I'm scared of the price of replacement cells. I know they are dirt cheap.
I want it because I don't like having a light that runs at full power for a few minutes, then spends most of its life running at reduced power from the trickle of charge left in the button cells.
I want it to run at full power all the time.

Click to expand...

Yes, the output varies less in time, with initial brightness in the whites and cyan (on 2016s) not being as high. Sorry, no runtime graphs, just been my experience.

If you want a bright rechargeable keychain light, get a Fenix L0D CE or something like that. Coin cells aren't the answer.

The current from coin cells doesn't fall off as fast as you might think though. They keep generating light at the 10 ma level or so for a very long time, many hours.

Since I got my freedom a few weeks ago i did a search and also found the rechargeable solution by batteryspace but decided not to proceed in getting them as primaries are cheap to buy, and they do last >10hours on high...and further more is cost more to ship the charger and coin cells than the stuff itself. So i'll stick to primaries.......