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CR123 cells, dangers, and things you should know about using batteries


I was a bit too alarmed at what I read. but I wasn't standing 10ft back to look at the whole picture. so I am sorry for misunderstandings I have caused by my being alarmed. some folks just need the higher power flashlights - I know I like a good bright flashlight. so I have changed the name of this page and redone some of the articles. Is venting a current problem? let's find out:
venting with flames
venting without flames
explosion, exploded
as of 2012, apparently some flashlights have sealed vents to prevent some problems. see the following CPF post.
there are such posts about flashlight on max+2xAA NiMH releasing gas when getting warm when being used and popping the tailcap a bit.

Problems with these cells / things to take note of:

  • the high power density of these cells, also Li-Ion.
  • the highly dangerous chemicals. read the MSDS on the product if you wish, or safety documentation on the product.
  • if they leak, vent with flames, or explode due to abuse or leaving the device on accidentally.

Problems to avoid:

  • non-USA cells
  • DON'T use the cells after flashlight/device goes dim or lost some power. it can reverse-charge the cells (and they are not to be charged, if you get the drift, especially backwards)
  • if you have a flashlight with a tailcap button, make sure it's off and can't be accidentally pressed after being left alone (pile of jackets, etc).
  • employees bringing their own flashlights (fire/safety reasons if flashlight accidentally left on)
  • full charge for The partial cell depletion (30%), coupled with cooler evening ambient temperature (65F-70F), appears at the moment to cause an explosion (during testing). Also, do not mix brands. when you buy them and need them as a set, buy them as a matched set, not separately.


  • use an 1850 Li-Ion rechargeable cell in place of 2xcr123a's.
  • use matched-pair cells if you use more than one. but again, avoid using until they are dim. saving money on these cells is not the best idea. they are less expensive now anyway, and you can get them in bulk on the cheap, there are usually price breaks for certain quantities.
  • OK to use a single cell, no problem of reverse-charging.
  • use a cr123A flashlight that has a vent? (probably common these days for those cell types)
  • don't let it get dim. "keep it bright"
  • battery station matched cells: 2006-07-11 CPF post: At the moment, Kevin of Battery Station, seems to be expending extra effort to actually test his cells, the best way he knows how, to assure that the cells are matched in as full up battery (not depleted at all) as well as he can. This step, after finding 3 out of 3 venting incidents in the partial depletion scenarios, in hind sight, was a *very* prudent move on his part.
  • you can test with 100&Ohm; resistor 1/8W and DMM should read about 2.8VDC (hard to take number off of curve without graticule).

These warnings and findings are found in the CPF (CandlePower Forums).

how to measure cells to see if they are "matched" (OK). (airlines) safe travel with batteries and devices.

dual cr123a flashlights with a button tailcap - Surefire G2 & M6 & 9P, Pelican M6. The M6 tailcap nearly went through a solid oak cabinet door - UPDATE: IF LEFT ON. sorry for not giving enough information folks. here is another article along the same lines, about leaving the flashlight on under certain conditions, flashlight was left on. Read the 1st and 2nd post especially (and later posts if possible) to see the solution to the problem what what causes explosions, safety rules to prevent, etc.

some say in a 2-cell system, if one cell is slightly discharged, the imbalance can lead to an explosion (please read the posts) - I can see how this would occur. a load on a series of cells you can think of like a resistor. resistors are spec'd by wattage and resistance in Ohms. Volts/Amps=Ohms (&Ohm;). 3V/1500mAH=2&Ohm;@3V*1.5A=4.5Wh. for 2 cells it's 6V/1500mAH=4&Ohm;@6V*1.5A=9W worst case. let' say one cell is hypothetically 2.3V and the other is 3V. a mismatch. put them in series with the load/resistor at far ends. you get 2.3V+3V=5.3V total voltage (so now we need to recalculate that resistor - a wirewound high-wattage potentiometer comes to mind). 3V-2.3V=0.7V of reverse-charge: it's easier to think of the problem this way - place the cells with the poles at opposite ends of each other. connect a wire between the ends of one side, and the resistor/pot/potentiometer/rheostat 4.7&Ohm;@25W $117 or a 5&Ohm@12.5W $45.16 (that's the term - rheostat) on the other side.

+    wire -
[]        []
[2.3v]    [3v]
[]        []
- resistor +

that 0.7v is going to charge that smaller cell - it's easier to see this way. how much voltage is a problem? on quick search, I did not find out. run a flashlight until it dims and then quickly measure the voltage. cells have a bit of recovery when they are not under load (is this a chemical thing?).

rheostat ohms (&Ohm;) estimator

W output @ VDC with rheostat resistance of minimum &Ohm;. 3.4k&Ohm; (3k4) at 6v/3.4e3=1.764mA current which means it's 6V*1.764mA=10.5mW resistor (we will round that up to a standard 1/8W, it's really a bit over 2/189 according to an HP 33s calculator or probably a hp35s calculator) is a good load value.
mAH= to make calculations easier.

a ceramic load resistor may do the job. electronics distributors like digikey, newark, mouser do have variable load/high wattage ceramic resistors/rheostats/l-pads. read: 3k4&Ohm; as 3.4k&Ohm;

not sure yet what a proper load resistor test would be, I suspect that only a partial load is put on the cell so you don't run it completely out of power just testing it (or you don't do this for very long, like a few seconds). too little load and the cell just shows as being OK, but only for a short time due to recovery.

avoid "Surefire" batteries, maybe avoid Eveready, Panasonic, Streamlight, Browning, and others due to PTC crimping. Avoid batteries made in China such as Sanyo.
2004-02-09: recall Fuji Power, A&T Fuji Power CR123A 3-volt lithium batteries originally provided with the Dorcy Spyder Tactical Xenon Light (Product 41-4200), also sold in packages of two flashlights under the name Dorcy Xenon Tactical Light (the company has probably long since finished with that by now).
search of for CR123A recalls between 1/1/2013 and 12/31/2017. as of 2014/10/15, last one was 2007.
Did you realize that in 2004, 63% of Lithium battery recalls were due to cells manufactured in China, and they only produced 34.5% of the batteries? That means Chinese batteries are twice as likely to be the subject of a recall [link 404'd]? [NEED CURRENT STATISTICS AND STATUS, ARTICLE LINK - ARE THINGS BETTER?]

2007-11: battery tester, 2005-07: article about flashlight+cr123a exposions, 2003-12: Lithium Ion Batteries linked to Airplane fires, 2006-07-11: testing links