The energy that a battery can deliver in the discharge process is called the capacity of the battery. The unit of the capacity is “ampere hour” and is briefly expressed by the letters “Ah.” The label value of the battery is called rated capacity. The capacity of a battery depends on the following factors:
The unit for measuring battery capacity is ampere-hour or amp-hour, denoted as (Ah). The capacity can also be expressed in terms of energy capacity of the battery. The energy capacity is the rated battery voltage in volts multiplied by battery capacity in amp-hours, giving total battery energy capacity in watt-hours (wh).
The battery capacity is the current capacity of the battery and is expressed in Ampere-hours, abbreviated Ah. Chemical Capacity – full storage capacity of the chemistry when measured from full to empty or empty to full. This is normally defined at a given C-rate and maximum and minimum voltages.
The most common measure of battery capacity is Ah, defined as the number of hours for which a battery can provide a current equal to the discharge rate at the nominal voltage of the battery. The unit of Ah is commonly used when working with battery systems as the battery voltage will vary throughout the charging or discharging cycle.
Now that you have the necessary information and adjusted discharge current, you can calculate the battery capacity by using the following formula: Battery Capacity = Actual Discharge Current (I_actual) × Discharge Time (t) For the previous example, assuming a discharge time of 10 hours, the battery capacity would be:
Capacity is calculated by multiplying the discharge current (in Amps) by the discharge time (in hours) and decreases with increasing C-rate. SOC is defined as the remaining capacity of a battery and it is affected by its operating conditions such as load current and temperature. It is calculated as: SOC = Remaining Capacity Rated Capacity