# CR123A depleted voltage



## STi (May 1, 2009)

Hello! I usually use AW RCR123A batteries and charge them at 3.7v...Recently I have been using regular cr123a batteries in one of my lights...Now do i just run it till it dies or do i need to dispose of at certain voltage to prevent venting?


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## csshih (May 1, 2009)

normally, the battery should be fine if you run it down in a single cell light..but.. there still have been rare instances where the battery vented... what brand of battery are you using? I'm sure some more educated user will inform you more.


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## ltiu (May 1, 2009)

I stop using it when it falls below 2.0v.

You will notice that the voltage starts falling rapidly (steep downward curve) below around 2.5v. So you may measure it and it reads 2.5v. Use it a bit, then measure it again and all of a sudden, it read 2.0v.


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## STi (May 1, 2009)

csshih said:


> normally, the battery should be fine if you run it down in a single cell light..but.. there still have been rare instances where the battery vented... what brand of battery are you using? I'm sure some more educated user will inform you more.


 
Battery Station and Energizer lithium photo.


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## dr-ebert (May 1, 2009)

By chance, I have a related question. I'm using a primary CR123A (Panasonic, 1550mAh) in a laser. This one recently stopped working, I found out that was because the voltage of the battery had dropped to 2.72V, which is too low for the constant current driver. However, I'm sure I haven't gotten more than about 250mAh out. So does someone have a graph that relates remaining capacity to voltage for the CR123A?

EDIT: I found a graph here. However, it's for a 2A discharge. I was discharging at ~400mA.


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## mdocod (May 2, 2009)

Hi dr-ebert,

CR123s will test right around 3V regardless of their state of charge. There is very little correlation between voltage and remaining capacity. Usually, once a cell us reading closer to ~2.75V or less, it's very dead.

keep in mind that just because you can measure 2.72V under NO load, does not mean that there will be 2.72V available when the cell is loaded by the device you install it into. Under a load, a dead CR123 will drop below 1V, but still read just under 3V open circuit. 

-Eric


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## dr-ebert (May 2, 2009)

That's what I thought. I've tested the cell in my LF3XT under load, and the voltage report says 0.4V, so it's dead. Now I just have to find out why it's drained so quickly - either it was a dud, or there's some current leak somewhere (more likely)...


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