I had a childhood friend that, when he needed flashlight batteries, got them from his mother who retrieved them from the refrigerator. Later, when I mentioned this to a college roommate, I was informed that HIS grandmother went a step further. She kept unused batteries in the freezer.
As preppers, we should probably all know the answer to this question: Can we extend the shelf life of flashlight batteries by refrigerating or freezing them? What do you think?
One thing is certain. If you freeze or refrigerate batteries, you must let them thaw for a couple of days and come up to room temperature before using them. Your car battery, for example, might crank on your hard-starting car for 15 minutes in the summer before dying but only two or three minutes in the winter. Cold saps a batteries’ strength dramatically.
But that’s in use. In storage, cold will slow electrical activity (leakage, in the case of batteries) and, in theory, stop the battery from running down. Or slow the battery from running down. Nothing will stop it completely. “All energy systems run downhill,” as they say.
As a child, comparing the performance of my flashlight to my friend’s flashlight (equipped with refrigerated batteries), I never saw much of a difference. But what if I conducted a controlled experiment? Would refrigeration make a measurable difference?
So, a while back I went to the store and bought six “D” batteries. They were neither dollar-store cheapies nor expensive alkaline batteries. They were Eveready-brand carbon-zinc batteries. I marked the date on the packages and put two in the freezer, two in the refrigerator, and two in the cupboard over the kitchen stove. Because of cooking heat, the last two were slightly above room temperature, both summer and winter, for the duration.
After two years, eight months and three days, I decided it was testing time. So I laid all the batteries on the dining room table for two days to thaw out and equalize in temperature. As regards the batteries stored above the kitchen stove, I really thought that they would die after just a couple of hours.
I tested them all simultaneously, side by side. I used three Rayovac-brand flashlights, all purchased at the same time, all equipped with standard bulbs (not LED, not Krypton). The flashlights were carefully labeled as to which batteries they contained.
The first thing that impressed me – amazed me, really – was how long the batteries lasted. When first started, they all appeared to give off the same amount of light; they were of equivalent brightness. After SIX HOURS they had all dimmed and needed replacement. SIX HOURS of continuous burning after 2.5 years of storage! I had expected two or three hours.
At the end of six hours they were all burning with equivalent brightness but had all dimmed. I would have been somewhat reluctant to have gone to the mailbox or out to the barn with any of them.
At the end of eight hours, they were all down to glowworm status. At this point the room-temperature batteries gave only a pinpoint of light and the refrigerated/frozen batteries a brighter glow.
BUT, as a practical matter, they all reached the end of their useful life at the same time (six hours) at which point they had equivalent brightness. You could have switched the labels around on the flashlights and no-one would have been the wiser.
I concluded that attempting to extend battery shelf-life by refrigeration was, and is, a waste of time. And that’s worth knowing, is it not? This was not, and is not, armchair theory. This was a real test with real batteries. If you repeat the test, you can expect the same results. Call it the “scientific method” in action.
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