Very few lead acid batteries are replaced because they stop working. In almost every case the battery is replaced because it doesn't work _well enough_ anymore. What is not generally realized is that something can be done at this stage which may prolong the useful life of the battery - quite often by many years, and that the same treatment carried out earlier in the battery's life may well have stopped the symptoms from occurring in the first place.
The reason for a battery failing is due to the chemical processes which take place in each cell when the battery is not fully charged. Even the slightest discharge condition allows both plates to react slowly with the sulfuric acid electrolyte to form lead ions. It is these lead ions which cause problems; they combine with sulfate ions in sulfuric acid to form highly insoluble lead sulfate. When this coats the plates of the battery, it fails to deliver enough power to be of use. The battery may well be serviceable every other way - only the "sulfating" stops the battery from delivering enough power to be of use.
The sulfating can effectively be removed, or prevented, by adding to each cell a chemical called tetrasodium ethylenediaminetetraacetate (often abbreviated to tetrasodium EDTA). This chemical forms co-ordination compounds with many metal ions, including lead ions formed in the discharge cycle of a battery. The compound formed by lead ions and the EDTA ion is not particularly stable in the acid medium of a battery, but when it breaks down again any lead sulfate regenerated tends to drop to the bottom of the cell where it lays harmlessly since it doesn't conduct electricity. Any regenerated EDTA ions are free to continue their work.
This is likely to occur if the motorcycle is used just for short trips, is infrequently used, or has at any time suffered from an inefficient charging system. Treating with the chemical can also help keep an original battery in use, and can help in bringing back into use a stored battery. It is also a once-only treatment, lasting the life of the renovated battery.
============================================================================ "No hour of life is lost that is spent in the saddle." - Winston Churchill The Nashville Flash - firstname.lastname@example.org - DoD # 412 -------------------- -- Dave Edmondson, only genuine with this label