Lithium battery is said to be uncomplicated, in fact, it is not very complicated, said simple, in fact, it is not simple. If engaged in this industry, then it is necessary to master some of the common terms used in the lithium battery industry, in that case, what are the common terms used in the lithium battery industry?
Common terms used in the lithium battery industry
1.Charge-Rate/Discharge-Rate
Indicates how much current to charge and discharge, generally calculated as a multiple of the nominal capacity of the battery, generally referred to as a few C. Like a battery with a capacity of 1500mAh, it is stipulated that 1C = 1500mAh, if discharged with 2C is also discharged with a current of 3000mA, 0.1C charge and discharge is charged and discharged with 150mA.
2.OCV: Open Circuit Voltage
The voltage of a battery generally refers to the nominal voltage (also called the rated voltage) of a lithium battery. The nominal voltage of an ordinary lithium battery is generally 3.7V, and we also call its voltage platform 3.7V. By voltage we generally refer to the open circuit voltage of the battery.
When the battery is 20~80% of capacity, the voltage is concentrated around 3.7V (around 3.6~3.9V), too high or too low capacity, the voltage varies widely.
3.Energy /Power
The energy (E) that a battery can put out when discharged at a certain standard, in Wh (watt hours) or KWh (kilowatt hours), in addition 1 KWh = 1 kWh of electricity.
The basic concept is found in physics books, E=U*I*t, which is also equal to the battery voltage multiplied by the capacity of the battery.
And the formula for power is, P=U*I=E/t, which indicates the amount of energy that can be released per unit of time. The unit is W (watt) or KW (kilowatt).
A battery with a capacity of 1500 mAh, for example, has a nominal voltage of typically 3.7V, so the corresponding energy is 5.55Wh.
4.Resistance
As the charge and discharge cannot be equated to an ideal power supply, there is a certain internal resistance. Internal resistance consumes energy and of course the smaller the internal resistance the better.
The internal resistance of a battery is measured in milliohms (mΩ).
The internal resistance of a general battery consists of ohmic internal resistance and polarized internal resistance. The size of the internal resistance is influenced by the material of the battery, the manufacturing process, and also the structure of the battery.
5.Cycle Life
Battery charging and discharging once is called a cycle, cycle life is an important indicator of battery life performance. The IEC standard stipulates that for mobile phone lithium batteries, 0.2C discharge to 3.0V and 1C charge to 4.2 V. After 500 repeated cycles, the battery capacity should remain at more than 60% of the initial capacity. In other words, the cycle life of lithium battery is 500 times.
The national standard stipulates that after 300 cycles, the capacity should remain at 70% of the initial capacity. Batteries with a capacity below 60% of the initial capacity should generally be considered for scrap disposal.
6.DOD: Depth of Discharger
Defined as the percentage of capacity discharged from the battery as a percentage of the rated capacity. The deeper the discharge of a lithium battery in general, the shorter the battery life.
7.Cut-Off Voltage
The termination voltage is divided into charging termination voltage and discharging termination voltage, which means the voltage at which the battery cannot be charged or discharged further. The charging termination voltage of lithium battery is generally 4.2V and the discharging termination voltage is 3.0V. Deep charging or discharging of lithium battery beyond the termination voltage is strictly prohibited.
8.Self-Discharge
Refers to the rate of decline in capacity of a battery during storage, expressed as a percentage decrease in content per unit of time. The self-discharge rate of a typical lithium battery is 2% to 9%/month.
9.SOC(State of Charge)
Refers to the percentage of the battery's remaining charge to the total charge that can be discharged, 0 to 100%. Reflects the remaining charge of the battery.
10.Capacity
Refers to the amount of power that can be obtained from the battery lithium under certain discharge conditions.
The formula for electricity is Q=I*t in coulombs and the unit of capacity of a battery is specified as Ah (ampere hours) or mAh (milliampere hours). It means that a 1AH battery can be discharged for 1 hour with a current of 1A when fully charged.
Post time: Aug-03-2022