L91 and Capsule

[Ksailork]

For a spare AA battery for my car's flashlight, I've placed an Energizer L91 primary lithium in an aluminum capsule which seals via threads against an o-ring. That has been tossed in the center console.

I got to wondering, however, in the higher summer heat environment of a car would any possible battery venting combined with confined containment be a safety concern.

Am I okay or should I store the battery otherwise?

Thanks.

 

[SilverFox]

Hello Ksailork,

Most batteries are good for 140 F. How hot does it get inside the capsule in your center console?

Tom

 

[Ksailork]

Thanks for your reply, Tom

How hot does the inside of my console get? - That is a good question that I cannot answer accurately. Published research shows that the inside of a car can approach 160° F. Does my car get that hot? Does the console get that hot? How long would it take to heat up the capsule and battery to that temperature? All questions that only a recording thermometer can tell me. Gut feeling - I think around 140° sounds more realistic. Of course, that puts it at the top end of the battery's comfort zone.

I am not sure how significantly L91s vent. There seems to be more instances of CR123's behaving badly. There are other options but what could be handier than the console. I'm hoping someone has direct experience or perhaps the collective experience of CPF can be the guidance to follow.

Thanks again,
Kent

 

[SilverFox]

Hello Kent,

My experience with lithium primary cells is that they handle storage very well. The problems start to show up when you use them in extreme conditions.

Understand that extreme storage conditions will render the cells with less capacity than a new cell stored under ideal conditions. With cells in a vehicle, I rotate them out yearly after the heat of summer has passed.

Tom

 

[shao.fu.tzer]

Just make sure to wrap that sucker in saran wrap first... You wouldn't want your cell to discharge in your aluminum carrier...

 

[Ksailork]

Shao, I isolated the ends of the battery with rubber o-rings at both the top and bottom of the aluminum capsule. Hopefully, that does the job. My luck they'll fall out and get lost when I retrieve the battery. Maybe the Saran Wrap™ is the best way to go.


And, a recording thermometer I did manage to get my hands on. NIST traceable.

The car, a sedan, is dark gray. Tested two separate days. Mostly cloudless days with ambient temperature reaching 91° F for the high. Altitude where I live; 5540 feet. Latitude: 42.8° North. I used no windshield screen and parked facing, not optimally, southeast. One of the days was windy; 10-15 MPH winds. The maximum temperatures I recorded were:

Glovebox: 124° F
Center console: 122° F
Car interior: 141° F
Trunk: 139° F

The maximum temperatures occurred around 3:00 to 4:00 p.m.

So, car temperatures do, without much question, reach the high end of battery's limits. Also, I tend to think I may see higher temperatures as we approach fall (northern hemisphere) as the interior gets more sun because of the sun's lower angle. I'll do another test in mid August.

I am sure by changing the parking angle and with a complete still day I could record even higher temperatures. Good thing we mostly use our car's flashlight at night - by then it may have cooled down. :)