Jim,
I have been following with interest over the last several days this thread on batteries and feel I have some information to share. To begin with, the only solution to a long term lead-acid battery bank is to make your own cells. Lead has a perpetual shelf life and oxidizes very little over time if protected. Contrary to the confusion established by the battery manufacturer cartels, both plates begin as simply pure lead (Pb). It is only after the initial charge is applied that the positive plate changes chemically due to the sulfur ion action. While home made cells will not have the high ampacity to pound ratio of commercial cells, they would have qualities most suitable to the long term prepper; namely serviceability and parts replacement. In addition, the positive plates could be made as thick as one wanted to prolong their life span. One could make them in 3 gallon HDPE buckets using standard stud mounted battery posts on the lids. The electrolyte is simply 30% sulfuric acid to 70% water. The plates need maximum surface area exposed to the electrolyte so one must drill many holes or corrugate the lead sheet to increase the surface area. Older plumbing stores still sell large sheets of lead for roof vent stack flashing. Or if one is handy with metal fabrication, a grid plate mold could be fashioned from steel and lead cast into it. Wheel weight lead-alloy will work too. Additional compounds such as antimony are not essential in a home made cell when you have a room full of replacement plates stacked up. They can be either coiled or flat plates. Do not expect the performance of a commercial cell from these, but when sustainability is all important, performance can be compensated for. Just add more cells to the array bank.
However, the real solution to perpetual deep cycle sustainable battery power for the long emergency lies not at all in the lead-acid cell. It lies in the lowly Edison cell [1]. A little known fact is that there are still banks of Edison cells in deep cycle applications today over 80 years old. Edison cell plates are nickel and iron and use lye and water for the electrolyte so they are alkaline and not acid cells. The plates do not corrode over time and they can be stored dry forever before filling and charging. All those nickel [US five cent coin]s that everyone is saving could [conceivably be melted down to provide the material for] the nickel plates for your grandkids batteries if you are wise today. Edison had over 50 patents on these cells and at the turn of the century entire fleets of delivery trucks used these day in, day out hauling massive loads with electric motors running on Edison cells. They were in direct competition with standard oil and big oil plans for gasoline vehicles so they had to be stopped. The electric car industry was eradicated as gas vehicles could go so much faster. Exide eventually bought all the dies and machinery and was still making them until they sold everything to china some years ago. The only importer now from that china plant to the U.S. is a company called beutilityfree.com which is where I bought mine. They only order like 4 times a year and it takes 3 months to get here and they are pricey, but I personally felt the investment was justified and truly multi-generational for my family. Companies like Eveready began several years ago making what was touted as “new technology” and called the cells “nickel-metal hydride” or NiMH as we all know them today. When they first hit the shelves, I just laughed and told my wife, “Look honey Edison cells in AA size”. – Dad4Him