Hi everyone,

Almost 10 years ago, when I helped with procuring emergency kits, I remember several commercial kits having a "20 year shelf life" battery. They were pretty unusual because they were a "Twist top" design...which actually made me worry because I thought people would pop them into a flashlight without twisting the batteries, and think their batteries were dead.

Now, looking at some of the vendors we used previously, these batteries seemed to have been dropped from the market almost completely.

They were marketed under the name "Code Red" and "Envirotron" and came in D-Cells.

You can see pictures of them here:
http://survivalchoices.com/pro577155.html
and here
http://replay.waybackmachine.org/20060106084941/http://www.quakekare.com/index.asp?PageAction=VIEWPROD&ProdID=47

Does anyone know what design these batteries used (Zinc/Air? The Code Red batteries suggest a liquid was involved) Were they so useless that that's why we don't see them on the market anymore? (Or is it just because lithium batteries are just so much better?)

Thanks!

As I seem to remember, way back when I considered the technology, they were conventional zinc–carbon units with the electrolyte held in a capsule that was fractured when you activated the battery. The main strength of this design is longevity. The main weakness is that the batteries are an obsolete, and fairly weak, chemistry that was further compromised by being made slightly smaller to keep allow for the separate capsule of electrolyte. At their best they had less total electrical capacity than the regular carbon-lead D-cells.

Zinc–carbon cells were largely replaced in the early 70s by 'heavy-duty' zinc–chloride cells which had a greater power store. These were, in turn, made obsolete by alkaline cells in the late 70s. The zinc–chloride cells were marginally better than the zinc-carbon cells whereas the alkaline cells have roughly three times the capacity of the zinc-carbon units.

For a twenty year storage capacity I'm thinking something along the lines of storing uncharged rechargeable cells and some way of charging them. A solar panel and/or human powered generator would provide a long shelf life and good durability in use.

I note that lead acid batteries, large units used in vehicles and boats, are stored dry, without the acid. The sulfuric acid is stored separately and poured in when the battery is initially put into service. The battery, once the acid is added, is charged and ready for use.

Very interesting, thanks for the analysis!

Yes the 20 year shelf life batteries were indeed zinc carbon cells with the electrolyte in a sepperate capsule that was fractured by twisting.

Obsolete due to low energy density, as posted above.

Lithium cells have an advertised shelf life of about 15 years, and would probably last 20 years in practice.

Most types of small rechargeable cell only reliably last a few years in storage.

Lead acid batteries if dry and sealed with the acid stored in bottles last some years in storage.

Crude, non portable, lead acid batteries are very easy to make and the materials store indefinatly.
Once made, the working life is very long and the capacity improves with each cycle.
The capacity is however very small in relation to the weight and bulk.
I once made 2 lead acid cells, each in a gallon glass jar. Each had a capacity of about 2 amp/hours, certainly potentialy useful in a long term emergency, but remember that the energy stored in a gallon glass jar, was only slightly more than that contained in a single AA cell !
So not exactly portable, but 6 such such home made cells could provide very limited lighting in a home every night, being charged by a PV module in the day.

Another option if planning for the long term, would be a return to the old technology of wet Leclanche cells.
These were used until at least the 1960s for door bells and railway signals.
These cells are not rechargeable, but unlike modern types, when run down, only the expended active ingredients require renewal not the whole cell.
The cell consists of an inner porous pot containing a carbon rod packed around with a mixture of manganeses dioxide and carbon powder. This porous pot is placed in an outer container of glass or plastic which is filled with a solution of ammonium chloride.
A zinc rod is placed in this outer container, often in a specialy shaped recess.
The voltage is about 1.5 volts, only moderate currents can be drawn, but the capacity is substantial on slow discharge.
I think it was about 100 A/H for the common "4 pint" size.

In use, the zinc rod dissolves and should be replaced when nearly consumed. If the cell fails to work correctly, then the electroylte should be dumped out and replaced with new.
Large stocks of zinc rod and ammonium chloride may be kept at very little expense. The porous pot and contents should last almost indefinatly.
The storage life should be indefinate if dry, the zinc slowly dissolves in the solution even with no current used.
3 or 4 such cells could power LEDs, a flashlight bulb, or a radio.

These cells are still made, for school science lessons, or could be made from scratch.
Proper care should be taken when handling the materials, though these are relatively low risk compared to many household chemicals. link to supplier

Lithium cells work fine for me for long term storage. Consider that over the next twenty years the odds are great that battery technology will evolve significantly. Solar powered heads up display GPS sunglasses, anyone?

Very interesting - thanks! I've been musing about home-made cells for a long time, primarily for LED lighting. I can make electrolyte (lye) from wood ash (mostly KOH I guess) ... what could I scrounge in order to kludge together a nickel-iron Edison cell? Or something better?

I believe that reasonably pure materials are needed to make a nickel iron cell. I dont believe that the impure solution from wood ashes would be suitable.
One might consider ready made nickel iron cells, stored dry and sealed with the elctroylyte stores seperatly.

Or home made lead acid cells.
Lead sheet as used for roofing keeps indefinatly, as does sulphuric acid.
To make a lead acid cell, 2 lead plates are immersed in the acid which should have a specific gravity of about 1.25.
Capacity is maximised by having the greatest possible area of lead. This may be achieved by a spiral formation, it is vital that the plates dont touch, they should be seperated by some porous and acid resistant material such as fibre glass.

The polarity is arbitary when first manufactured, but one plate should be marked positive and one marked negative to avoid later confusion.
Pass current into the cell to charge, the initial capacity will be tiny, but it improves with each charge/discharge cycle.
The working life should be 20 years or more.

I was thinking more of simply contacting a battery manufacturer and seeing if they could ship some good quality deep cycle batteries to you dry. Kept cool and dry I suspect the batteries, stored without any acid inside, should last a good long time. Acid storage would be an issue but not an insurmountable one.

As much as I like the idea of manufacturing my own cells, I've made a few small cells when I was in school, I think it is better to use existing designs.