Prediction of remaining battery discharge time based on stepwise linear regression

Lead-acid batteries are widely used in industry, military, and daily life as a power source. When the lead-acid battery is discharged at a constant current intensity, the voltage decreases monotonously with the discharge time until the rated minimum protection voltage (Um, 9V in this question). Aiming at the prediction of the remaining discharge time of the battery, this paper comprehensively analyzes the influence of current intensity, voltage, and battery attenuation on the remaining discharge time, and establishes mathematical models respectively.