What Is DOD, SOC, SOH?

Basic Parameter Indicators of Energy Storage Battery: What is DOD, SOC, SOH?

Battery capacity (Ah)

Nominal voltage and nominal ampere hour, which reflect the battery capacity, are one of the important performance indexes to measure the battery performance, and are the most basic and core concepts of the battery. It represents the amount of electricity discharged by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.), usually in Ah. Electricity Wh= power W* hours h= voltage V* ampere hours Ah. Taking a battery cell with 51.2V and 100Ah as an example, it means that the capacity of the battery is 51.2V×100Ah=5120Wh, which is what we usually call 5 kWh. Battery capacity is divided into actual capacity, theoretical capacity and rated capacity according to different conditions. Theoretical capacity refers to the battery capacity in the most ideal state; Rated capacity is the capacity marked on the equipment that can work continuously for a long time under rated working conditions; The actual capacity will be affected by temperature, humidity, charge and discharge rate and other factors. Generally speaking, the actual capacity is smaller than the rated capacity.

Rated voltage (V)

The rated voltage of an energy storage battery refers to its designed or nominal working voltage, usually expressed in volts (V). The energy storage battery module is formed by connecting single batteries in parallel and in series. Parallel connection increases the capacity, and the voltage remains unchanged. After series connection, the voltage is doubled, and the capacity remains unchanged. You will see parameters similar to 1P16S in the battery PACK parameters: s stands for series cells, p stands for parallel cells, 1P16S stands for: 16 series and 1 parallel-that is, 16 cells with a voltage of 3.2V, the voltage is multiplied after series connection, and the rated voltage is 3.2 * 16 = 51.2v.

Charge-discharge ratio (C)

The rate reflect that charging and discharge capacity of the battery; Charge and discharge rate = charge and discharge current/rated capacity. A measure of the speed of discharge. Generally, the capacity of the battery can be detected by different discharge currents. For example, when a battery with a battery capacity of 100AH is discharged with 14A, its discharge rate is 0.14C. Usually, when talking about the scale of an energy storage project, it will be described in terms of system maximum power/system capacity, such as 2.5MW/5MWh industrial and commercial energy storage project. 2.5MW is the maximum operating power of the project system, and 5MWh is the system capacity. If it is discharged at a power of 2.5MW and can be discharged in 2 hours, the discharge rate of the project is 0.5C.

Depth of charge and discharge (DOD)

DOD (Depth of Discharge) refers to the percentage of the discharged capacity of the battery to the rated capacity of the battery during the use of the battery. For the same battery, the set DOD depth is inversely proportional to the battery cycle life. When one aspect of performance is improved, other aspects of performance will be sacrificed. For example, if DOD is 80%, the cycle life of lithium battery can reach 6,000 ~ 12,000 times.

State of charge (SOC)

SOC(State of charge) state of charge, which indicates the percentage of battery remaining power to the rated capacity of the battery. Used to reflect the remaining capacity of the battery, indicating the ability of the battery to continue working. SOC is 0 when fully discharged and 1 when fully charged, which is generally expressed as 0 ~ 100%.

State of Health(SOH)

The state of health (including capacity, power, internal resistance, etc.) of SOH(State of Health) battery is the ratio of the discharged capacity from Wally state to the cut-off voltage and its corresponding nominal capacity. To put it simply, it is the ratio of performance parameters to nominal parameters after the battery is used for a period of time. The new factory battery is 100% and completely scrapped is 0%. According to IEEE standards, after the battery is used for a period of time, the battery should be replaced when its fully charged capacity is lower than 80% of the rated capacity.

ADAYO Power energy storage battery has the following types:

DA802 balcony photovoltaic micro-storage battery 51.2V 2240Wh

PA05A wall-mounted energy storage battery 51.2V 5120Wh

SP2500M mobile energy storage and balcony micro-storage two-in-one battery 48V 2496Wh