how does heat affect longevity of batteries

[Lincoln]

My truck is parked in direct sunlight each day and gets very hot because it is parked in the sun. I leave my 4D Mag-Lite with alkaline batteries in my truck each day. How does this intermittent (but extreme) daily heat affect the longevity of the battaries?

How would it affect my AA flashlight with lithium batteries?

 

[Marduke]

You want to look at the "Projected Service Maintenance" charts. Energizer lithium batteries are "Lithium Iron Disulfide".

http://data.energizer.com/PDFs/temperat.pdf

 

[Lincoln]

Since it is essential that I keep the batteries reasonably fresh for the emergency flashlight for the truck, I looked at the Eveready research data that Marduke referenced assuming that I would never want my batteries (that I keep in my flashlight in my truck for emergencies) to be at 80% or less of capacity.

What I gathered from Eveready's research relative to temperature and shelf life, is that both alkaline and lithium batteries would have less than 55% of their normal shelf life (given my 80% rule) if stored at a constant 104 F as oposed to storing them at a constant 68 F.

I suspect that having intermittently (but daily) high temperatures in the truck would cause batteries to decline in capacity even more rapidly.

For battaries on the "front line" I see there is a need to test them at least every few months, whether lithium or alkaline.

 

[Marduke]

The problem with alkalines in heat is more than discharge, but an increased likelihood of leaking. Not spending all of their time at a high temperature (long period fluctuation) isn't worse, but better for them. But assuming their entire life is spent at the higher temperature is a safer assumption. With that in mind, your 80% at 100F is reached at 8 years for lithium and just over 3 years for alkaline. However, many people that use alkalines in a vehicle use the 6 month check and 1 year replacement cycle. If you're frugal, you could take the old batteries and use them in non-critical applications such as clocks, remotes, and area/work lanterns after they have done their service in the car.

 

[SilverFox]

Hello Lincoln,

Battery manufacturers suggest that when batteries are exposed to high temperature extremes, like left in a vehicle in your case, you should replace them annually at the end of summer.

I believe this applies both to Alkaline and Lithium batteries.

Tom

 

[PhotonBoy]

Working from my memories of Chemistry courses I took about 40 years ago, the rate of chemical processes doubles (approximately) for each rise of 10 degrees C. So a battery at 50C (122F) will degrade at about 8 times the rate it does at room temperature of 20C (68F).

 

[Marduke]

Working from my memories of Chemistry courses I took about 40 years ago, the rate of chemical processes doubles (approximately) for each rise of 10 degrees C. So a battery at 50C (122F) will degrade at about 8 times the rate it does at room temperature of 20C (68F).

It depends on the specific chemical process in question.

 

[MrAl]

Hi again,

I have to agree that there is no battery that seems to like heat, except for
mild heat like 20 deg C or about that. Some batteries dont like cold either,
like the Lead Acid type, which can not create power when it gets too cold
(although warming it with a hand can revive it).
The difference between too cold and too hot though is quite different. When
a battery is too cold it might not put out the energy requirement but when warmed
up it works again, but if it gets too hot it self discharges too fast and looses it's energy
and it can not be revived, at least until it is recharged again.

 

[LuxLuthor]

How much cooler is it in an average trunk vs. passenger compartment?

This man has the perfect solution.

 

[Lane]

How much cooler is it in an average trunk vs. passenger compartment?

This man has the perfect solution.

That's funny stuff! :laughing:

 

[1dash1]

How much cooler is it in an average trunk vs. passenger compartment?

This man has the perfect solution.

I'd say he's got great flashaholic potential. :laughing::devil:

 

[drmaxx]

Working from my memories of Chemistry courses I took about 40 years ago, the rate of chemical processes doubles (approximately) for each rise of 10 degrees C. So a battery at 50C (122F) will degrade at about 8 times the rate it does at room temperature of 20C (68F).

Diffusion processes increase their rate by 35% for each rise of 10 degrees C. These might be quite relevant in battery chemistry

 

[asdalton]

Diffusion processes increase their rate by 35% for each rise of 10 degrees C. These might be quite relevant in battery chemistry

None of these rules of thumb is very useful. For one thing, they get the functional form wrong. The temperature dependence of rates is typically in the form r = r0*exp(-E/kT), where the exponential dependence not on temperature, but rather negative reciprocal temperature. So even if the idea of doubling rates every 10 degrees has some empirical fit to a limited body of data (which I suspect is from organic chemistry in water near room temperature), it's not something that you can extrapolate very far.

Interestingly, there are some broad correlations that apply across materials of a given type. For non-ideal gases, these usually depend on the critical temperature and critical pressure of the gas. For metals, the melting point tells you a lot. (For the latter, see: A. S. Dalton and E. G. Seebauer, Surface Science 601 (2007) 728-734. )

 

[koala]

Same reason why you buy that big bulky fridge. They all have some sort of chemical in it, and it degrades faster when exposed to heat.

 

[drmaxx]

None of these rules of thumb is very useful. For one thing, they get the functional form wrong. The temperature dependence of rates is typically in the form r = r0*exp(-E/kT), where the exponential dependence not on temperature, but rather negative reciprocal temperature. So even if the idea of doubling rates every 10 degrees has some empirical fit to a limited body of data (which I suspect is from organic chemistry in water near room temperature), it's not something that you can extrapolate very far.

Very OT:
Your comment is scientifically correct, but for chemical reaction in aquatic matrixes the rule is amazingly satisfying. This has something to do with the fact that the reciprocal temperature in Kelvin does not change drastically between 0°C and 100°C. Additionally, many aquatic reactions seem to have an Arrheinius activation energy between 40 and 50 kJ/mole.
And yes, it is not an universal constant and you can not extrapolate it very far, but for the discussion in question you do not need to extrapolate a few 100°C.
And I can assure you that for diffusion in aquatic solutions the 35% rule is quite good! That's the fastest way to distinguish between reaction limited / diffusion limited processes...

 

[BobDeLaLuz]

Working from my memories of Chemistry courses I took about 40 years ago, the rate of chemical processes doubles (approximately) for each rise of 10 degrees C. So a battery at 50C (122F) will degrade at about 8 times the rate it does at room temperature of 20C (68F).

My practical experience supports you. My wife and i teach disaster preparedness classes and have recommended Lithium for emergency use since the 90's. We found that with outside temps reaching 90-100F, the glove compartment temperatures were running 120-130 degrees F. This is high enough to cause all our Alkalines to leak (and fail) in two summer months.

By comparison, we threw a handful of CR123 batteries in the same car in 1999 and a month ago found them, they were in excellent condition (some were in a UKE UK 2L, others were loose in the glove compartment, they all worked perfectly well).

My conclusion, is that I will stop using Alkaline as emergency batteries and stick with Lithium.