Warming a battery?

[webley445]

Found an issue of Field and Stream at work. I was bored so I flipped through it. There was an article about "50 Things ALl Outdoorsmen Should Know".
One of the "things" was about how to get a little more life out of batteries that were failing/draining in small electronics, main reference was to GPS unit.

The article stated,".... supercharge weak batteries with an air activated hand warmer duct taped to the outside of the battery compartment...".

Now I ask you guys, does this work or is it a crock? /ubbthreads/images/graemlins/confused.gif

 

[James S]

If it's cold enough that you're carrying air activated hand warmers with you then it probably would get them working well enough for one last position fix. But not gonna make them new again, but if you only need that last position fix to radio to the rescue team, it would help /ubbthreads/images/graemlins/smile.gif

 

[gwbaltzell]

A battery is based on a chemical reaction and, like most, is highly affected by temperature. A look at this Energizer data sheet (in pdf) should give an idea how much.

 

[SilverFox]

Hello Webley445,

I have noticed that a flashlight that sits in my back pack in cold weather will burn a little brighter if I first stick it in my pocket for a few minutes to warm it up.

This effect is not as noticeable when using lithium batteries.

As far as bringing a dead battery back to life - good luck. As James mentioned, you probably will get a little bit of run time, but if you need more than that, change the batteries.


Tom

 

[Steelwolf]

It all has to do with how much unreacted chemical is left in the cell and how warm do you need to get it before that concentration of chemical will react vigourously enough to supply the electrons at a rate sufficient to power your device. Remember that chemical reactions will take place at different levels of vigour depending on reactant concentration, catalyst present and temperature. You can't do much about reactant concentration or catalyst, but you can certainly increase the temperature.

Even lithiums can benefit from this, but because they are so cold-tolerant, you would see little difference except at extremely cold temperatures. By which time, you would probably be using all the heat packs on yourself just to keep your blood flowing. /ubbthreads/images/graemlins/tongue.gif

 

[mrme]

In South America, I once saw a kid put some otherwise dead D cell batteries on a wood burning stove to warm them up and get some more run time out of his toy truck. It worked for him, but heating up batteries on a stove is not exactly safe.