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Thread: Keeping batteries cold makes them last longer.

  1. #1 Keeping batteries cold makes them last longer. 
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    I understand that there have been a lot of myths surrounding whether or not this is true but I can clearly say that there is in fact some truth behind this.

    I was intrigued to find out for myself and decided to carry out an experiment. I took 4 already use standard alkaline batteries, put two in the fridge for a week and left the other two at room temperature.

    After a week I took them out and used them in a standard Kodak digital camera, the batteries that had been in the freezer lasted a lot longer than the ones that had just been left on my side.

    Both sets of batteries had been used in the same way yet the colder ones were a lot more effective.

    Has anyone else had any experience with this?


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  3. #2  
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    Since chemical reactions slow down at lower temperatures, it stands to reason that the self discharge rate of your batteries might decrease, giving you a little longer shelf life. However, an alkaline battery has a shelf life of around 7 years or thereabouts, so your week of shelf life would not make much difference.

    Your test isn't worth much unless you verified that the batteries were identical and had an identical state of charge at the beginning of the test. That's not likely to be the case, from the information you provided.


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  4. #3  
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    I can verify that the batteries were identical, they were from the same pack and been used for equal amounts of time before the experiment.
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    I still don't put much stock in your experiment. There are just too many variables. The batteries may have come from the same package, but there could still be some manufacturing tolerances. Suppose some of your used batteries had 10 percent of their life remaining and some had 5 percent. That's only a 5 percent difference, but the better ones would last twice as long in the camera as the others. Then there could be differences in how the camera was set up, what mode it was in, etc.
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  6. #5  
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    A voltage and current meaasurement through a known (or at least identical for the test) resistance would be more useful in evaluating the batteries.
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  7. #6  
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    This 'myth' has worked for me before, not necessarily to extend life, but to breathe some life back into a dead battery that won't hold a charge. If a laptop battery or cell phone battery is dead and won't hold a charge, freezing it in a waterproof container(like a zip-loc bag) can sometimes rejuvenate it.

    As far as your test, a digital camera is a horrible way to measure battery life. Too many variables. How long was the screen on for each test? Were you using flash? If you don't have the equipment needed to take precise measurements as was pointed out in other posts, a flashlight would be a much better indicator. Simply turn the flashlight on and record the time until the light goes out.
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  8. #7  
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    I was under the impression that cold will make your batteries lose charge quicker - this is why NASA keep batteries warm as in cold spots in space the batteries will drain quicker - at least that is what I thought........
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    In theory it seems that a cold battery wouldn't be as good as a warm a battery-

    electricity works by using a voltage to knock valence electrons loose from the electron shell. Since it takes energy to loosen up a valence electron, and since a cold battery has a lot less thermal energy than a warm battery, it seems like it would take more energy to knock the valence electrons loose from the cold battery- far more energy than the warm battery. Plus thermal energy alone means that a warm battery potentially has more energy to spend.

    So far as theory goes, I'd lean on the warm one being better than the cold.
    No idea is untouchable. If an idea is infallible, then everyody on earth can test it and learn its truth- it can stand on its own merit. If an idea must be defended and is not allowed to be questioned, then the idea should never be accepted, for it is zealotry.
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  10. #9  
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    as a layman I agree with the logic of Bosscheese - the irony is that electricity is more efficient when cold at least when referring to the electronics of a computer chip which is explained in some part by what phonons do:

    http://en.wikipedia.org/wiki/Phonon

    I think this is mostly to do with speed of transmission as there is less phonon movement to get in the way but it is more expensive to cool something to enough of a temperature so it doesn't work out too well. please correct me on all this if I am way out.............
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  11. #10  
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    I completely forgot I had posted here!

    Well, suppose we take it to the extreme. Lets say we freeze a battery to absolute zero. At absolute zero, there is no energy in an atom. No energy means no free electrons to conduct. it wouldnt matter how strong of a voltage you put on that battery, if theres no free electrons, there would be no current. So to create free electrons, you would need to heat up the battery a bit to free up some electrons to create current.

    In this scenario you have any voltage with infinite resistance, no current. This would be an open circuit.

    Taken to the opposite extreme in which you super heat a battery before applying voltage, you would free up a massive amount of electrons. As soon as you apply a voltage, you'd get a massive amount of current with a small voltage because the superheated metal would have very little resistance.

    In this scenario, you would have high current even with a very low voltage, because of very low resistance. This is equivalent to a short.

    Given all that, an open circuit is useless, whereas you can do something with a short, such as put a resistor in series with it. A warm battery is definitely better.
    No idea is untouchable. If an idea is infallible, then everyody on earth can test it and learn its truth- it can stand on its own merit. If an idea must be defended and is not allowed to be questioned, then the idea should never be accepted, for it is zealotry.
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  12. #11  
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    I think a few of you are forgetting that batteries are based on chemical processes, and the cooler temperature is intended to slow the chemical exchange. The movement of the electrons is sort of irrelevant, as conductivity and resistance are not a factor until AFTER the chemical process has taken place... and it's the chemical process in a battery which is the relevant variable in this question about temperature and battery life.
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  13. #12  
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    Guess I did think too far into it- right you are about chemical processes in the battery. But its still true- if a battery were taken down to absolute zero, there would be no energy for the chemical reactions to occur, whereas a superheated battery would have plenty energy to occur. Still means that a warm attery is better than a cold one.
    No idea is untouchable. If an idea is infallible, then everyody on earth can test it and learn its truth- it can stand on its own merit. If an idea must be defended and is not allowed to be questioned, then the idea should never be accepted, for it is zealotry.
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  14. #13  
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    The claim was made about storage temperature of the battery, not operating temperature. After you put it in the camera, it would soon warm up to ambient temperature.
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    "The claim was made about storage temperature of the battery, not operating temperature. After you put it in the camera, it would soon warm up to ambient temperature."

    Yes, but it was stored differently, the other battery was kept at room temperature. If the cold would slow down the reaction relative to the battery that was stored at room temperature that might account for something, but batteries are supposed to increase their rate of discharge with more extreme cold/hot temperatures....
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