Why do some people store batteries in the freezer? Should you store batteries in the freezer? Ask Science looks into the deep freeze.
I’m Just Getting Warmed Up…
Even when the cell isn’t connected to a circuit, these chemical changes still occur, though at a much slower rate. “Self-discharge” is the term used to describe how cells slowly lose their “charge” or their ability to carry out the reactions that produce electricity, when they’re just sitting around on a shelf somewhere. How fast a cell self-discharges depends on a lot of factors, including the chemicals used inside the cell and the temperature outside.
It turns out to be true that putting batteries in colder temperatures can slow the self-discharge rate of their cells, however just how effective this is depends on the type of battery. Modern alkaline batteries have such a low self-discharge rate that storing them in the freezer is nearly ineffective. Lithium batteries (both standard and rechargeable) are even better.
On the other hand, rechargeable nickel cadmium (NiCd) and nickel metal hydride (NiMH) batteries have really high self-discharge rates that are drastically reduced by storing them in colder temperatures.
However, most battery manufacturers recommend against storing batteries in the freezer or refrigerator for several reasons. First, excess moisture can significantly degrade battery life by causing corrosion around the anode and cathode contacts. In addition, the extreme cold temperatures can cause seals in the battery to rupture, which greatly reduces battery performance. Finally, a cold battery has to be at room temperature before it can operate at maximum performance.
So it turns out that as usual, my wife’s intuition was correct. My family has been shortening the life of their batteries for years all because we didn’t understand the science behind batteries. Hopefully this episode will save your family from a similar fate. Now please excuse me while I go and take the batteries out of my freezer and put them in a drawer where they belong.
If you liked today’s episode, you can become a fan of Ask Science on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at email@example.com.