In the interval T0–T1 until the voltage 10.8 V (21.6 V for 24 V) is reached the battery is charged by little current to prevent any battery damage at possible failure (shortcut at any battery cell).
In the interval T1–T3 until the voltage 14.7 V (29.4 V) is reached the battery is charged by constant current 2.5 A (2.0 A).
In the intervalT3–T4 until the charging current drops under 0.25 A is charged by constant voltage 14.7 V (29.4 V).
In the interval over T4 is charged by constant voltage 13.65 V (27.4 V) with the charging current drops gradually to zero.
The maximum charging current for various versions is written in the table Basic Technical Parameters. For each case this current cannot exceed the limit (Rated output current) – (Actual current on OUT DC).