Letter Re: Shelf Life of Batteries?

Mr. Rawles,
You had an inquiry on your site about long term storable charged batteries. Such a topic came up recently on the amateur radio reflector called hfpack. There is one such battery that is well suited for storage. It is called a silver chloride battery, and they are activated by adding salt water. One use is in torpedos – see http://www.naval-technology.com/contractors/electrical/hbl/.
Another source of information is at:
energy.sourceguides.com. These have a high energy density, but are primary cells and not rechargeable. Still, if you plan for an urgent one time need arbitrarily in the future, silver chloride batteries may be the best bet. – “Sun Dog”