Why do lead acid battery manufacturers use different alloys in their batteries (lead-calcium, etc.)?
A4 – The composition of the plate grid alloy can have a major effect on operating characteristics, such as behavior on float charging and cycle life. Older lead-antimony designs have good cycling capability but require frequent water additions, particularly towards the end of life, due to antimony migration between the plates. Cells with lead-calcium alloys require far less watering, but tend to have a poor cycle life. Lead-selenium alloys are actually low-antimony types with the addition of selenium as a hardening agent. Such alloys promote good cycling capability, while maintaining a constant and fairly low level of water consumption. Many variants on these alloy types are commercially available.