Method, device and system for estimating the charge state of a battery

A device for estimating state of charge of a battery, the device and the battery being integrated into an energy-consuming device, the device comprising:

• at least one voltage sensor configured to measure a voltage across terminals of said battery;
• at least second sensor configured to measure a second physical parameter of said battery or of its environment, wherein the second physical parameter is chosen from among:
• a current provided or absorbed by the battery, an internal temperature of the battery, an ambient or internal temperature, a mean of values of said at least one time series of voltage measurements, a charging or discharging status of said battery, a charging or discharging rate, an impedance of the battery, and a measurement of a state of health of the battery;
• a memory configured to store a set of non-linear regression models of the state of charge of said battery;
• and
• a processor programmed to implement a method for estimating the state of charge of the battery comprising:
• acquiring at least one time series of measurements of voltage across the terminals of said battery and as at least one other time series of measurements of the second physical parameter of said battery or of its environment;
• determining, as a function of said measurements, an operating regime of said battery;
• choosing, as a function of said operating regime, a non-linear regression model from among a predefined set of such models;
• and
• estimating the state of charge of said battery by applying said non-linear regression model to said time series of voltage measurements and to said or to at least one said other time series of measurements;
• wherein said method is executed with said sensors and said memory.