The optimal charging current of the battery is considered to be current equal to 0.05 of its capacity (equalizing charge). So for a battery with a capacity of 55 Am / h, this value is 2.75 A, and for 60 Ah it is already 3 amperes. The purpose of this method is to ensure full recovery of the active masses in all battery plates.
That is, a standard car battery 55Ah is charged with a current of 2.75-5.5A, and for 60Ah batteries, the charging current is set in the range of 3A to 6A. But you need to know that the smaller the charging current, the deeper the charge, although it takes more time.
In the “Charging current” cell, you need to indicate with what kind of current you plan to charge the battery from the charger. By pressing the “Calculate” button you will get the necessary time to fully charge a car battery. How long should I charge the battery to start the car?
During the constant voltage mode, the charging current starts to decrease. When the charging current drops to a predefined minimum current value (e.g., 0.05 C), the charging process concludes, indicating the battery is fully charged (e.g., battery state of charge is 100%).
To fully charge the battery, you need to eventually get it up to 4.2V. But if you just apply a 4.2V across it when it's completely discharged, you'll be putting 4.2V-2.75V=1.45V across a 130mOhm impedance. That means the charging current will be on the order of 10 amps, which is much higher than the battery is rated for.
To achieve a consistent charging loss for the battery, the approach begins by employing Coulomb counting to calculate the current battery state of charge. Then, Equation (3) is utilized to compute the charging current value. where Ichg represents the charging current, and Req represents the equivalent impedance of the battery. Figure 16.