Lithium battery state of charge:
The SOC of the battery, the full name is State of Charge, the state of charge, also known as the remaining power, represents the ratio of the remaining capacity of the battery after a period of use or long-term shelving to the capacity of the fully charged state, commonly expressed as a percentage. It is generally represented by one byte, that is, two-digit hexadecimal, which means that the remaining power is 0%~100%. When SOC=0, it means that the battery is fully discharged, and when SOC=1, it means that the battery is fully charged.
SOC algorithm has always been one of the key technologies in the development and application of lithium-ion battery management systems (BMS). The higher the estimation accuracy of SOC, the higher the cruising range of electric vehicles can be with the same capacity battery. High-precision SOC estimation can maximize the performance of lithium-ion battery packs.
At present, the most commonly used calculation methods are the ampere-hour integration method and the open-circuit voltage calibration method. By establishing a lithium-ion battery model and collecting a large amount of data, the actual data is compared with the calculated data. This is also the technical secret of each company. It takes a long time. A large amount of data is accumulated, and it is also the most technical part of Tesla. Tesla has applied for more than 100 core patents in BMS-related fields such as lithium-ion battery cooling, safety, and charge balance.
The state of charge (SOC) estimation of lithium-ion batteries is a basis for battery application research. The deep charge and discharge of lithium-ion batteries in use will greatly reduce their service life. Accurate SOC estimation can prevent this situation; the remaining power The accurate display can also help the car control system to calculate the drivable mileage, and the driver can also better plan the driving route.
How to charge a lithium-ion battery?
1. Prevent charging at high temperature. If the operating temperature is higher than the specified operating temperature, that is, the charging environment is above 35 °C, the power of the battery will continue to decrease, that is, the power supply time of the battery will not be as long as usual.
2. Charge according to the standard time and procedure; all the pursuit of 12-hour long charging and the use of single-cell lithium-ion batteries for automatic shutdown are wrong.
3. Keeping the lithium-ion battery properly charged and discharged can prolong the battery life. Maintaining the lithium-ion battery power at 10%~90% is beneficial to protect the battery. When charging the batteries of digital products such as mobile phones and notebook computers, there is no need to reach the maximum value.
4. Lithium-ion battery charging temperature range: 0~45 degrees Celsius, lithium-ion battery discharging temperature range: -10~+60 degrees Celsius.
5. Due to the characteristics of the lithium-ion battery itself, it has almost no memory effect. Therefore, the new lithium-ion battery in the user‘s mobile phone does not require special methods and equipment during the activation process. It is best to charge according to the standard time and standard method, especially do not carry out an ultra-long charge of more than 12 hours.
