Some thoughts on water usage (which is often a result of outgassing) in deep cycle and other high antimony batteries:
Battery outgassing"There are, however, several operational drawbacks of antimony designs when used in float applications. These include high water consumption, high float current, antimony poisoning of the negative plate, and a high self discharge rate. In general, these characteristics can be explained as follows. The antimony used in the positive grid will plate out into the electrolyte solution over time. This free antimony attacks or “poisons” the negative plate, causing it to lose charge. This depolarization of the negative plate then causes more float current to flow to attempt to keep the plates fully charged. This increase in float current increases the gassing rate evolved from the plates, thereby increasing water consumption. This process continues and accelerates as the battery ages. The net result over time is increasing float current (energy cost to charge the battery and heat generation), increasing grid corrosion rates (accelerating the aging process), increasing gassing rates (including hydrogen evolution) and increasing water consumption (more maintenance)."
Antimony poisoning leading to increased water usage"The rate of antimony- poisoning is directly related to the operating temperature, *charging voltage* and the antimony content of the alloy."
Antimony poisoning due to high charging voltage.
