SureFire 123A Battery Testing

SureFire 123A Battery Long Term Testing


A few weeks ago I received a phone call from SureFire asking if I would be interested in testing some old 123A lithium primary batteries.  How old?  Well, the batteries in question were manufactured over 12 years ago, in February 2003.  Of course I was interested!

Lithium 123A batteries are known for their long shelf life which is a great advantage for any person or organization that needs to maintain a stockpile for ready use.  Along the same lines, they are also an excellent choice for a device, such as an emergency flashlight, that may be stored for long periods between uses.  Most 123A batteries are advertised as having a 10-year shelf life so I was looking forward to finding out how they perform after more than a decade in storage.

The test subjects arrived a week later and, aside from the slightly yellowed tape on the boxes and old style battery labels, everything still looked good as new.  I carefully examined each battery and saw no indications of corrosion, leakage, or deformation.

SureFire 123A Battery Testing

Next, I checked the open circuit voltage of each battery, comparing them to each other and some newer 123A batteries I had purchased (manufactured in November 2014).  The results were satisfyingly consistent with all batteries, “new” and “old” alike, measuring within a few thousandths of a volt of each other.  So far so good!  All that remained was testing the batteries to see how they behaved under load.

Performance was measured by conducting runtime tests using three different flashlights.  Three runs were conducted with each flashlight with the results plotted on runtime charts.  For each flashlight the tests were conducted in the following order:

  1. Powered by “old” batteries with 02/2003 manufacture date (marked 02/2013)
  2. Powered by “new” batteries with 11/2014 manufacture date (marked 11/2024)
  3. Powered by “old” batteries with 02/2003 manufacture date (marked 02/2013)

123A Long Term Testing – Runtime Results

I still wasn’t sure what to expect so I started things off with a relatively easy test using the 110 lumen version of the SureFire E1B Backup, powered by a single 123A battery.

SureFire E1B Backup Runtime Testing

The twelve year old batteries effectively matched the new one for nearly 30 minutes of continuous operation and showed a negligible difference in output at one hour.  The gap widened after approximately 70 minutes as the older cells dropped out of regulation and began to decline.

Next up, the SureFire E1D Defender was used to see if a more demanding load made any difference in performance.

SureFire E1D Defender Runtime Testing

Once again the older batteries held their own for the first half-hour of use, with the gap slowly widening over the next 30+ minutes.  Encouraged by these results, I brought out the SureFire P2X Fury for the final test, powered by a pair of 123A batteries.

SureFire P2X Fury Runtime

As with the other flashlights, the older batteries had no trouble powering the Fury and matched the new ones for 35 minutes before falling behind.  There were no issues with any of the batteries during testing.

Merely relying on runtime from tests like this can be a little misleading, primarily because most of us don’t turn our flashlights on and simply let them run continuously until the batteries are depleted.  A more accurate reflection of the amount of work performed (light produced) by the batteries can be observed by graphing the cumulative amount of light produced over time.  This can be achieved by calculating the area under the curve in the previous charts.

SureFire 123A Battery Testing

This highlights the fact that although the older batteries begin to lose power sooner than the newer ones, this occurs at a point where output levels are already declining.  Basically most of the work (defined here as producing light) has already been accomplished.  The size of the difference increased over time as shown in the following table:

Difference in Cumulative Output Over Time

 30 minutes45 minutes60 minutes75 minutes90 minutes105 minutes120 minutes
E1B Backup0%-1%-1%-2%-4%-7%-8%
E1D Defender-1%-2%-4%-7%-9%n/an/a
P2X Fury0%-3%-7%-9%-9%n/an/a

These results also seem to indicate the reduction in light output is minimized in lower powered flashlights.

123A Long Term Testing – Conclusions

I wasn’t sure what to expect out of these senior citizens of the battery world and it was a pleasant surprise to see how well they performed.  The best estimates I have read state 123A lithium batteries should retain approximately 90% of their capacity after 10 years in storage.  Even at twelve years of age these batteries easily accomplished that and, considering most of us change batteries before they completely die, the apparent loss of capacity may be as low as 4 or 5%.

SureFire 123A Battery Testing

I don’t normally worry about the age of my batteries since I go through them so quickly while testing and reviewing flashlights.  However, it’s good to know that these SureFire 123A batteries are reliable even after 12 years on the shelf.  I’m about to put the rest of them back “on the shelf” and plan to bring them out again in a few years to see how they are holding up.

The old batteries used in these tests were provided by SureFire.  They were recently uncovered while reorganizing a warehouse and were apparently stored there since they were new.  The storage conditions there are estimated to average 68°F and 20-45% humidity.  The new batteries were purchased from Amazon.

Posted in Flashlight Accessories, Flashlight Reviews, SureFire Reviews and tagged .


  1. Steve in MA,
    One very important factor may have been left out in the percent of power loss in the old timer cells which could reduce the overall percentage loss, is after more than a decade (12 years) battery companies are tweaking their cells to perform better and be more efficient than they were a decade ago. This could account for a small part of the differences between the old and new cells test. thus reducing the actual percentage loss of the older cells.
    I’m pretty amazed how well the batteries (cells) actually hold a charge!

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