The direction of current through the battery determines whether it is charging or discharging. The battery is trying to push current in a particular direction. If the current flows in that direction, the battery is discharging. If the current flows in the other direction, the battery is charging. It is a little bit like a spring or a clockwork toy.
The nature of the load (constant current, constant power, or variable load) affects how the battery discharges. Constant power loads, for example, will lead to a different voltage drop pattern compared to constant current loads. 8. Internal Impedance:
Battery discharge curves are based on battery polarization that occurs during discharge. The amount of energy that a battery can supply, corresponding to the area under the discharge curve, is strongly related to operating conditions such as the C-rate and operating temperature. During discharge, batteries experience a drop in Vt.
When the battery does reach the voltage reference, the voltage loop overrides the current loop and the battery current increases to zero. The direction of the current to charge or discharge the battery is controlled by a logic signal (indicated as “Direction” in Figure 2).
Keep the discharge power unchanged, because the voltage of the battery continues to drop during the discharge process, so the current in the constant power discharge continues to rise. Due to the constant power discharge, the time coordinate axis is easily converted into the energy (the product of power and time) coordinate axis.
The charging conditions of the battery: charging rate, temperature, cut-off voltage affect the capacity of the battery, thus determining the discharge capacity. Method of determination of battery capacity: Different industries have different test standards according to the working conditions.