Method and electric equipment for calculating secondary battery SOC (system on a chip) and self-learning OCV (open circuit voltage)-SOC curve

Abstract

The invention provides a method of a self-learning OCV (open circuit voltage)-SOC (system on a chip) curve and a calculating method of secondary battery hopower state SOC value. With the calculating method, SOC value calculated through the calculating method can accurately display dump energy of batteries. Different from conditions that non real time and inaccuracy of battery internal resistor measurement in the existing technology lead to inaccuracy of self-learning OCV-SOC curve, the method of the self-learning OCV (open circuit voltage)-SOC(system on a chip) curve and the calculating method of secondary battery hopower state SOC value calculate internal resistor value r in a set time through measuring the most value of battery current and battery terminal voltage in a preset time in self-learning OCV-SOC curve so as to calculate open-circuit voltage during the preset time. Battery resistor can discharge with battery and time change are fully considered, so that battery internal resistor can be accurately traced during charging and discharging process of batteries, evenly-distributed OCV-SOC corresponding points can be acquired, and more accurate OCV-SOC curve can be acquired.

Description

technical field [0001] The invention relates to a method for measuring and calculating the electric quantity of a secondary battery in an electronic device and the corresponding electronic device. Background technique [0002] Most of the existing battery fuel gauges use the ampere-hour integration method to detect battery power. This method will not bounce back during the entire charging and discharging process. Using a higher-digit AD for current sampling can obtain good accuracy. However, the ampere-hour integration method cannot detect the leakage current generated after the system is shut down, resulting in cumulative errors due to inaccurate initial battery power values ​​after each boot. Although this error can be corrected by detecting the open-circuit voltage corresponding to the battery power when the battery is turned on, this corresponding relationship will change with changes in the cycle life of the battery and the ambient temperature. Some existing methods st...

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Problems solved by technology

However, the ampere-hour integration method cannot detect the leakage current generated after the system is shut down, resulting in cumulative errors due to inaccurate initial battery power values ​​after each boot.

Although this error can be corrected by detecting the open circuit voltage corresponding to the battery power when starting up, the corresponding relationship will change with the cycle life of the battery, the ambient temperature, etc.

Some existing methods start with detecting the battery temperature or the number of cycles, and use different coefficients to compensate, but this type of method needs to test the battery at various temperatures and lifespans in advance to calibrate the coefficients, and cannot solve the problem of individual differences in batteries ;Although other methods can self-correct the OCV-SOC curve, they often have poor accuracy

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