Testing CR123 batteries with volt meter?

pahl

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May 19, 2003
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South Dakota USA
I have some used CR123's I'm going to use up on a E1/KL1.
I checked the voltage of each battery with a volt meter thinking the higher voltage ones would be the better ones to use.

I found that some of the batteries measured a higher voltage on the meter, but when put in the E1/KL1 that light went into moon mode.

For example I had one that measured 2.8 and the KL1 was in moon mode. Then I had one that measured 2.4 and the KL1 was at full brightness with that cell in it.

I'm preaty sure my meter is working ok. Should I be using a resiter to put a load on the battery when cheching them for voltage with a meter?

How do you check your CR123 batteries?
Does anyone make a battery checker that works on CR123 batteries?

Thanks,
 

milkyspit

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Sep 21, 2002
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Pahl, just by dumb luck I've been doing some research on 123s lately. The other day I realized that 123s seem to be a little different animal from alkaline cells, in that 123s tend to stay at a relatively high voltage even after being heavily depleted, whereas with alkalines there seems to be a steady decline in voltage over their entire lifetime. So you can test alkalines on a DMM quite nicely be checking their voltage, but for 123s you need to check their CURRENT.

More specifically, I believe the more accurate indicator of a 123's health is to test its momentary unloaded current flow. Do this by setting your DMM to measure Amps (use a high setting!), then place the probes on the 123 terminals and leave them just long enough to register what appears to be their max current flow. This will appear in perhaps half a second. Then pull the leads off! Continued unloaded current flow in a 123 will probably damage it.

I'll be posting a thread to explain my findings in going through my 100 Tekcell and 18 Surefire 123s (some interesting conclusions, so you might want to watch for the thread), but for now I'll say that I've established a minimum of 7.0A momentary unloaded current flow as what a 'fresh' 123 ought to be able to provide. The cell is probably still in decent shape, although partially depleted, below that point, and by the time it registers 2.0A or less it's probably on its last legs.

Hope this helps!
 

CM

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Sep 11, 2002
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Mesa, AZ
I have cells that metered at 2.8V also and it was dead. So what I do to test a 123 is put it in an Arc LS /ubbthreads/images/graemlins/grin.gif If I get full brightness, it's got some capacity leftover. This is similar to Milkyspits ammeter test but not so detrimental to the battery. I say detrimental because the ammeter test is really applying a short circuit (almost) to the cell. He's absolutely right about doing this for a *very* brief moment.

CM
 

Doug S

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Jun 20, 2002
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Chickamauga Georgia
Milkyspits ammeter test is a valid method of screening CR123 cells for condition. One note of caution: double check that your meter is on a 10A [or higher] scale because usually the lower ammeter ranges are fused at levels that a fresh CR123 can blow in an instant. Tested for short periods, up to a few seconds, there is no basis for concern about the cell itself. If you over do it, the cell has an internal PTC device that will [non-destructively] begin to limit the current.
 

Timothybil

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Nov 9, 2007
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The great state of Misery (Missouri)
I really like the ZTS Mini Battery Tester (MINI-MBT). It uses a patented pulse-test process to load test the cell to get a more accurate picture of how it really is. Not cheap but worth the money as far as I am concerned.
 

lumen aeternum

Enlightened
Joined
Sep 29, 2012
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813
I really like the ZTS Mini Battery Tester (MINI-MBT).
Useful. The full size one does myriad types of coin batteries. I suppose it needs an idea of the battery mAh capacity to do the pulse testing?

ZTS Inc. MBT-1 Multi-Battery Tester for More than 30 Different Battery Types.

 

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