Store batteries in the freezer?

[Mighty Hd]

My wife's father for many, many long years has stored his batteries in the deep freezer in the garage. The man swears by this method.

He claims it makes them last longer.

He had some batteries that looked to be at least 10 years old. Old Duracell & Energizer's I believe. We needed them for something and back he came with them....I was sure they would not work but were strong as new.

Was he just lucky or is there any truth to this?

 

[Mr Happy]

Sure. Just as cold slows down food deterioration, it can slow down battery deterioration. It probably is more suitable for primary cells like alkalines than for rechargeable ones.

For cells that have delicate membrane separators like NiMH, I would be worried about ice crystal growth causing internal damage. In that case it is best to go with the manufacturer's recommended minimum storage temperature.

But for alkalines, since they are essentially cheap disposable cells, what's to lose? (Then again, what's to gain?) Just be sure to avoid possible food contamination, and warm them up to room temperature before use.

 

[Fallingwater]

I put all my rechargeables in the fridge, not the freezer. According to official specs, LiIon cells lose 10% capacity every year is stored at 40% charge at room temperature, while they only lose 2% if stored in the fridge.

 

[TKO]

I put all my rechargeables in the fridge, not the freezer. According to official specs, LiIon cells lose 10% capacity every year is stored at 40% charge at room temperature, while they only lose 2% if stored in the fridge.

Could you provide a voltage for 40%? I think remember reading that at 3.7 v Li-ion had 20% charge remaining?

Thanks.

 

[SilverFox]

Hello TKO,

40% is around 3.8 volts.

Here is a formula that you can play with...

Tom

 

[TKO]

Thanks SF!

 

[Robert15]

Energizer's web page has some technical documents that have quite a bit of useful information.

This alkaline battery appication manual discusses shelf life:
http://data.energizer.com/PDFs/alkaline_appman.pdf

It says (page 11):
Shelf Life:
The recommended storage temperature for alkaline batteries is -40° C to 50° C.

Cylindrical alkaline batteries will lose approximately 3% of their capacity per year when stored at 20° C due to slow electrochemical reactions that continually occur. Cold temperatures will slow these reactions down and warm temperatures will increase these reactions.
The following graph (fig. 15) shows the impact of storage temperature on battery capacity.


Their NiMH application manual is here:
http://data.energizer.com/PDFs/nickelmetalhydride_appman.pdf

This manual also discusses storage conditions (page 25):
The common rule of thumb for nickel-cadmium cells that a 10°C increase in storage temperature halves the time required for a cell to self-discharge to a given level remains approximately correct for nickel-metal hydride cells.
...
Recommended Storage Conditions

Store at the lowest feasible temperatures (-20°C to 30°C being the generally recommended storage temperatures).
...
Store in a clean, dry, protected environment to minimize physical damage to batteries.


I would be a little worried about a typical household refrigerator or freezer being dry enough to store batteries.

 

[Mr Happy]

That's interesting information. Since a domestic freezer is nominally at -18°C it is within range of the temperatures quoted.

Regarding dryness, I wouldn't worry too much about that. It is easy enough, and probably advisable, to place the batteries in a sealed plastic bag or other container.

 

[Melchior]

A sealed plastic container with a bag of silica gel.

 

[koala]

The problem is condensation. Once the battery is taken out of cold, it will sweat. So don't take it out of the bag if it's out of the freezer, wait at least 3-5 hours for the temperature to settle.

I would store 'ready-for-use' cells in the fridge rather than the freezer. It takes a shorter time to warm up.

Let me dig an ancient thread where I freeze some cells for research purposes, yes the start freeze time is April 2006, I got it off my the file details I first created for saving the initial capacity tests.

Results - NiMH long term(>1yr) storage at -17.4C/0.68F

I thought I was in for a 3yr run but one day, my gf emptied the fridge for cleaning before I got home from work . That killed my 2+ year test cells.

This thread also discuss some freezing
http://www.candlepowerforums.com/vb/showthread.php?t=133581