Bulk, Absorption, and Float are the 3 main charging stages of a typical lead acid battery. In addition, there could be one more stage called equalizing charge. Bulk Charging Stage So, the first charging stage is bulk, in which the battery is typically less than 80% charged.
For example, some Lead-acid batteries, like Solar Tubular, can accept high charging currents in bulk stage. The second condition is regarding the endpoint of the bulk stage. When we push energy into the battery, the battery voltage will be increased.
A common way to keep lead–acid battery charged is to apply a so-called float charge to 2.15 V. This stage of charging is also called “absorption,” “taper charging,” or trickle charging. In this mode of charging, a short voltage pulse is applied to briefly bring a battery voltage to 2.15 V and then discontinue the charge.
The voltage must be lowered to typically between 2.25 and 2.27 V. A common way to keep lead–acid battery charged is to apply a so-called float charge to 2.15 V. This stage of charging is also called “absorption,” “taper charging,” or trickle charging.
The lead–acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté. It is the first type of rechargeable battery ever created. Compared to modern rechargeable batteries, lead–acid batteries have relatively low energy density. Despite this, they are able to supply high surge currents.
A typical lead–acid battery contains a mixture with varying concentrations of water and acid. Sulfuric acid has a higher density than water, which causes the acid formed at the plates during charging to flow downward and collect at the bottom of the battery.