Need Math help... 3W LED on 1xCR123

I made a 1xCR123 out of an old Maglight C-cell and dropped a Maglight 3W LED lamp in it.

I can anyone tell me how long this thing should run on a Surefire CR123?

Will it fade or be strong up till the battery dies?

Thanks for the help!


PS. Pic to follow

Yes, please post a pic, this sounds interesting.

My MagLED module draws about 0.9A when cold, but it has a temperature protection circuit, which will reportedly cut the power to about half as it warms up. So if primary CR123s are around 1.3Ah, I'd guess... let's see... maybe up to three hours if you just turn it on and let it run. However, if you use it in several shorter "bursts" (a few minutes at a time) and let it cool off between them, the total runtime will be less, as it draws more current when it's cool. So, to sum it up, I'd expect anything from 1.5 to 3 hours.

I don't think it will fade much before it dies. Well, any more than the temperature protection will fade it regardless of what you power it with.

Thanks! I guess it will work as a single cell discharger if anything. Will get a picture up tonight.

Maybe I'll get some protected RCR123's for it. Will the MagLight handle the extra voltage of RCRs?

oregonshooter said:

Maybe I'll get some protected RCR123's for it. Will the MagLight handle the extra voltage of RCRs?

Click to expand...

I don't know, but since they make a different LED upgrade for 2 and 3 cell lights, I think it would be safer to use the 3 cell version for that application. Under load, three alkalines are about the same 3.6V as a li-ion cell. That's proportionally a fair bit more than the 2 cell version was designed for, so it might burn out.

Thanks Valolammas,

I'm not sure what to do with the light. The only purpose I can see for it is for running low CR123's that I take out of my Aviator done to nothing.

Will likely sit in the shop as a utility light.

Pics:






Spare battery in tailcap.

Don't short that spare battery out! :shakehead

Good point. It is upside down and the top is taped off to prevent that.

It doesn't look quite as stubby as I thought it would, but cute nevertheless! Nice work.

I think I read somewhere that CR123s that don't work in the Aviator anymore still have about 25% of their juice left. I use them up in a Fenix P1 and it does run surprisingly long with them.

I could have made it an inch or so smaller, but the way it is now the thumb lands on the button when gripping the light in the palm.

My new "bump in the night" light for the house. Sits next to the night stand to help me find the shotgun.