Using Up CR123 Batteries

Kalsu

Newly Enlightened
CPF Supporter
Joined
Jan 14, 2010
Messages
172
So when using CR123 batteries in you flashlight and you have consumed the useable power in the batteries there is still power left in the cells. How do you guys go about using the rest of the power in the cell?
I thought that I saw on here where someone was making an LED set up with two magnets on the ends that could be used as a night light/bedstand light to deplete the rest of the cell? What do you guys do?
 

xxo

Flashlight Enthusiast
Joined
Apr 30, 2015
Messages
2,707
I have one of DatiLED's Battery Drainers.

EJrrLMQ.jpg


6HIaVn5.jpg


This particular Drainer has a color changing LED and will run on both 1.5 and 3V cells. I added the 3D printed diffuser.

I also have a original (single mode) ML25 Mag that will run on 1-3V that would be good for draining CR123's using adapters.
 

Dave_H

Enlightened
Joined
Nov 3, 2009
Messages
796
Location
Ottawa Ont. Canada
What kind of voltage (open-circuit) do these CR123's show when no longer good for high-drain (light) but still have some
useful energy left? Probably around 3.0v but not much below? (judging from Lithium coin cells).

Dave
 
Last edited:

Dave_H

Enlightened
Joined
Nov 3, 2009
Messages
796
Location
Ottawa Ont. Canada
I was going to suggest some solar garden lights which run from 1-2 cells may work. Careful as some boost ICs are only good
up to 1.5v or so, and 3v might do damage. You'd need to know what's inside.

One IC which is probably OK is CL0116, spec'ed up to 3v; have seen them just marked "0116".

Dave
 

Kalsu

Newly Enlightened
CPF Supporter
Joined
Jan 14, 2010
Messages
172
I have one of DatiLED's Battery Drainers.

View attachment 32455

View attachment 32454

This particular Drainer has a color changing LED and will run on both 1.5 and 3V cells. I added the 3D printed diffuser.

I also have a original (single mode) ML25 Mag that will run on 1-3V that would be good for draining CR123's using adapters.
Yep that is what I was thinking of. Gotta get me one of those.
 

fulee9999

Enlightened
Joined
Mar 3, 2021
Messages
620
I usually use my TinyNugget for that purpose. Runs an amazing amount of time on low after the battery has run out of it's main juice. I usually get another tens of hours of light that way.
I run my Malkoff M61 in an MD2 body with 2xCR123, and it drops out of regulation at around 2.69V per cell, after that it goes into the "still usable" bin for another vampiric light.
 

troutpool

Flashlight Enthusiast
CPF Supporter
Joined
Apr 22, 2010
Messages
1,175
Location
Arizona
The Peak Logan has been mentioned many times in other threads as a good battery vampire for CR123 cells.
 

Dave_H

Enlightened
Joined
Nov 3, 2009
Messages
796
Location
Ottawa Ont. Canada
How about a simple cheap solution, LED plus resistor. You pick both. Just need to find or rig up a holder for cell.

Brightness may vary as cell runs down but I suspect where most LEDs stop producing light, the cell will be exhausted.

I have only one 2xCR123 light which does not get a lot of usage, and a few partly-spent cells, could give it a try.

Dave
 
Last edited:

etc

Flashlight Enthusiast
Joined
Dec 19, 2004
Messages
5,649
Location
Northern Virginia
I run depleted AAs in a 3xAA Malkoff M61LLL configuration. It's dim but does seem to get out a few lumens for a few days.

The same thing for dead 123s. In a "9p" body
 
Top