Over the years, calcium has been added to lead plates to improve grid strength and conductivity and reduce gassing and its self-discharge rate. With this, the low-maintenance or maintenance-free battery was introduced. However, the alloy plate still consists of more than 99% lead. Whether the battery is calcium-calcium, calcium-silver, lead-calcium, or lead-antimony, it is still essentially a lead-acid battery and suffers premature failure from sulfation just like any other lead-acid battery. The Infinitum Desulfator reverses and prevents sulfation, typically restoring batteries to the best possible condition, maximizing its life span up to 3 times.
An excerpt from Popular Mechanics:
HOW IT WORKS: MAINTENANCE-FREE BATTERIES
Like many things in life, the term “maintenance-free” is only partially true. Lead-acid batteries normally consume some of the water in their dilute sulfuric acid electrolyte during a normal charge-discharge cycle. It actually electrolyzes into hydrogen and oxygen and escapes as gas. So adding water periodically is necessary to keep the plates flooded. Maintenance-free batteries use a calcium alloy of lead instead of an antimony alloy, which reduces the amount of electrolysis.
In addition, the amount of free-standing electrolyte above the plates is designed to be much higher in a new maintenance-free battery. This means that there’s enough electrolyte to keep the plates covered even after a few seasons of normal use. So, during the battery’s normal service life there should be no need to add water. Any abnormal electrical system condition or high ambient temperatures may boil off more than the normal amount of water, however. Adding water may extend the service life of these supposedly maintenance-free batteries.