Lithiums and temperature extremes

[Seabass]

Does anyone know what are the temperature extremes that lithiums can handle?

I'd like to leave lithium powered lights in my car and the temperature around here ranges from -30C to plus 30C (-22F to 86F). Considering that the batteries will be left in the car overnight those ranges could be pushed even further.

Will lithiums still be okay?

 

[SilverFox]

Hello Seabass,

Welcome to CPF.

I looked up lithium batteries on the Energizer web site and they list the storage and operating temperature range of -40 F to 140 F (-40 C to 60 C).

Tom

 

[Seabass]

Doh, I could've done that. /ubbthreads/images/graemlins/banghead.gif

Thanks.

 

[jenks]

Hello Seabass:
I grew up in Winterpeg. It's a great place to be FROM. /ubbthreads/images/graemlins/hahaha.gif

I was thinking about this the other day. I know lithiums are great but is there any data on alkalines at about zero degress celcius? The energizer data has only 20 degrees and minus 10. The lowest we usually see here at sea level is somewhere in between.

 

[HarryN]

I did a paper study of the effect of temp on a flashlight, using the data sheets for a variety of components. While the batteries are often "rated" at (-30 or -40) (C and F are close in this range), the voltage is quite reduced, esp. once you start drawing substantial current.

Interestingly, the LEDs are also limited (on paper) to (-40 C) even Luxeons. I suspect that the issue is the silicone encapsulant, but not certain.

For a final treat, look at the electronics. 90% of the LED flashlights on the market use electronics with components that are "unrated for", or will go way out of spec even at ( 0 F). At (-40 C), many are way out. The EE's like to tell me that "cold is ok", but then try to pin them down and "prove by spec or test" - different answer.

Since my training was in Chem E, we actually have to pay attention to details like temperature on our materials.

If you really want to get the EE's going, ask them about (-55 C) or below. There are very few components on the market officially rated for this range.

The great thing about LED's, is that they truly love cold - and get brighter for similar power conditions.

 

[Doug Owen]

I think cold is better, within reason of course. For most things. Gain is an exception (it gets a bit better hot), but leakage doubles every 6 or 7 degrees C as I recall. And with it some kinds of noise. Cold means quiet.

It's very common practice to cool 'commercial grade' parts (let alone industrial or mil spec ones like the LM317, 217, and 117 respectively). Cool them way out of their specified temperature range, getting better performance all the way. Like liquid nitrogen cold. Thermal drifts are often a PITA, but can be worked around.

The general problem with the low end specs is often just staying in range, rather than dying altogether. Mechanical things, like fans, and chemical reactions (like batteries) are another matter. Likewise, physics issues like gas pressure I guess. But the dumb electrons don't know they're cold. And most of the changes with lower temperature are positive (gets better) and/or modest.

For sure there's going to be a drop off in OTS parts certified under minus 55, demand is somewhat limited. NASA can supply the part if you really need it. Otherwise, since the Army doesn't expect to be there, they don't want to buy radios for troupers not there..... They determine what happens, if they spec'd minus 65, you'd see a shift. Neat system, really.

Doug Owen