Best battery size for vehicle-stored flashlight

Hi all,

I'm looking for information about what kind of battery (AA, AAA, CR123, Alkaline, Lithium etc) would be best for storing in a flashlight kept in a vehicle? Where I live, summers can reach 90-100 degrees (hotter in a car), and winters can get down to 20 degrees or so. So, I'm looking for something that will last longest under those conditions and still provide several hours (~4) of a modestly-bright output (~10-30 lumens). I'll pick the flashlight once I have a battery type selected. I'm not in the habit of regularly rotating batteries, but I also understand that I probably will have to start. But, of all battery types, which will last longest under the described conditions?

I see temps -15°F to 100F (probably 125+ in the car). I found Eneloops will lose a lot of capacity (about half) in just 1 year in my car...nowhere near the "70% after 10 years" (lower for older generations). So don't rely on those.

Stick with CR123 or L91 (AA Lithium). Those will work in brutal temps and last up to 20 years (maybe even past expiration date). Of course, two CR123 or two L91 will give you more runtime.

markr6 said:

... Stick with CR123 or L91 (AA Lithium). ...

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Agreed. That's what I use in my truck and I live where winters are cold and summers are hot.

Had frequent alkaline leakage problems with lights stored in the truck years ago before changing to lights using Energizer Lithium primary and CR123A batteries.

Another vote for Lithiums of some kind.

More specifically, I think a nice setup for a vehicle is:

1. Headlamp with moderate flood for fixing a tire at night, searching through your trunk, looking under the hood, etc. For example, Zebralight H32Fw or H52Fw. Personally I find the pure flood on the H302/502 too floody but that's an option too)
2. Torch with a decent amount of throw for spotting things in the distance. 200m throw should do it, but more won't hurt! Something like a Olight M22 (dirt cheap at gearbest right now)
3. Spare batteries for each

wopr67 said:

... So, I'm looking for something that will last longest under those conditions and still provide several hours (~4) of a modestly-bright output (~10-30 lumens)....

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With modest output requirements, I'd suggest a wide voltage (0.9-4.2v), mechanical clicky, single AA light, running a lithium primary (as mentioned above). The AA platform gives you the option of picking up any AA/AAAs at a gas station. And if you don't mind a bit of battery MacGyvering, some lights are easy to rig to run on any battery (eg, D cell through 18650).



Cells 3,4 and 5 are good lithium primary candidates for storage:
- Energizer L91, lithium iron disulfide LiFeS2, ~4.5 watt-hrs, but lower voltage/low max output
- Saft 14500, lithium thionyl chloride LiSOCl2, ~9.4 watt-hrs, huge capacity but lowest continuous draw rating (~15 lms and below should be fine)
- TI 14505, lithium manganese dioxide LiMnO2, ~4.5 watt-hrs, higher voltage/higher output, same as the CR123 chemistry

+1 vote for lithiums. 123 cells and/or Energizer L91 AA cells. I only use those in my car, nothing else.

I keep a SF G2/M61LLL, a SF G3/M61LL, an Elzetta/M60 3cell/two-stage, a SF 9P with a Malkoff M31LL/ L91 AA cells, and both types of spare cells.

Thanks everyone for the replies. Sounds like I'll be looking for a flashlight that takes AA lithium cells.

Store bought lithiums work great in clocks and portable devices in my non climate controlled garage.
And last longer in flashlights used in climate controlled enviornments.

Coast lights and Lux- Pro are readily available and if your car is broken into not likely to get stolen.

if you want absolutely reliable


multicell cr123 light
-------------------------------
and use these cells specifically

Panasonic BR series

these are used in spaceflight and missile platforms that need dc power battery backup to
just sit in horrible conditions and work when needed, no BS, no leaks, no outgassing

http://www.digikey.com/en/product-h...-series-lithium-primary-cylindrical-batteries

I suggest the CR123 sized BR 2/3

http://www.digikey.com/product-detail/en/BR-2/3A/P133-ND/6676

http://store.batteryspecialists.com/lithium-cylindrical-batteries-br-2-3a.html

you can leave these 180 degree heat for 10 years and expect them to function normally

^^ good info.

Ps, love the screen name.

127.0.0.1 said:

if you want absolutely reliable

multicell cr123 light
-------------------------------
and use these cells specifically

Panasonic BR series

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Great info in what is turning out to be a great thread.

I just checked the specs of the CR123A-sized Panasonic BR-2/3A-3V 1200mAh. It is rated for a maximum continuous current of 2.5A. That compares favorably with the 1.5A of most standard CR123A batteries.

That's good news for those who want to stay within spec with flashlights like the Nitecore MH20, Olight S1, and the ZebraLight SC32w, all of which pull more than 1.5A from CR123A on their highest modes.

Edit: Sorry to say, the spec I found on the BatterySpecialists.com web page is wrong. The maximum continuous discharge for these batteries is only 2.5mA. Thanks to Robert M. for catching my error.

RobertM said:

Actually, the spec is 2.5mA, not 2.5A. These are for low draw applications.

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KeepingItLight said:

Thanks for this.

I was relying on the info from the BatterySpecialists.com web page linked in by the following post. Although it says, "Max. recom. Cont. Current: 2500mA," it also has a link where you can download the Panasonic datasheet. I should have done that. The datasheet confirms the 2.5mA maximum that you supplied.

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bykfixer said:

^^ good info.

Ps, love the screen name.

Click to expand...

Apparently (authoritatively even) he's him...

-jk

Depends a little on the application. If the flashlight has a true lock out (no parasitic drain), the CR123 lithium cells are probably the best. When not in use (no current drain at all) the chemistry in effect hibernates, so these cells tend to have very long shelf life. If you have an application that has a parasitic drain, the cells remain active, and they run down in much less time than the nominal shelf life, no matter how small the drain. The only rub with CR123's is that they don't work very well when they are cold. I have a Sunwayman V25C in my car with CR123's.

I'd place my vote on an AA light with a lithium primary because of the wide availability of AA's. It could be harder sourcing a CR123 if you need one. That said, you can get some pretty amazing CR123 lights with good runtimes and levels in remarkably small sizes. I like my Olight S1, for example.

In those conditions lithium primaries will outperform others. Li ion is not a serious option, I'm tired of those being recommended. Lipo are even worse, NiMH worse, and cadmium worst.

Alkaline are undeniably better than any rechargeable, because LiIon are not batteries, they are capacitors, and capacitors loose energy overtime.

Alkaline compete with lithium when price becomes an issue, which for storage, unless you have 50 cars, should not be a problem, so lithium primaries will rule. Lithium AA/AAA have very little energy for their volume and price, 123s of various sizes are much better.

If you lived somewhere it gets cold (20° is not cold) then I would recommend Alkaline as it will outlast lithium in the cold (20-40 years, in fact my grandpa gave me a refrigerated6v that was 40years old) lithium primaries reaction doesn't slow in the cold, so they work better when on, but waisted when off.

Lithium vs alkaline is a classic example of the better the material being burned, the more expensive you have performance for what you get. Rubidium batteries are way more powerful than lithium, and perform in -200F, but they cost to much to make for consumers to use, they are not even mentioned. Far far superior to lithium, but performance doesn't matter if things cost to much. Why are cars not madebpf titanium?...

AA headlamp with lithium primaries.

It should be noted not to let digital switch batteries turn you off. Just slip a piece of plastic in there and be sure you take a mental note. that's a silly thing to hold your choice back. be sure to try to turn the light on in order to check the effect of your power cut.

^^ good idea

Building on that theme:


^^ ensure you remember with tags


^^ after removing the cap.

I keep a few lights in my car. A couple 2*AAA penlights and a 2*AA light for the 2AA light I also have a red traffic cone diffuser.
Regarding batteries, the penlights might have alkalines in them, but they are primarily so the grandkids can use them to read. I might have duraloops in them. I do have a 2 AAA or 2AA battery usb battery charger in the car at all times.

The 2AA light I keep powered with a pair of duraloops, and I top them off now and then. NiMH do perform fairly well above freezing, and better and better in more moderate temps. I can't comment on any loss of capacity because in reality they get very little use in the car. I also have a four pack of lithium energizers for back-ups. They're still fresh because the package has never been opened.