NOVELTY - The method involves determining a characteristic state of battery that is intermediate between its full charge and discharge, by detecting a peak in the evolution of derivative of its no-load voltage, or characteristic state of full charge or discharge, or defined by crossing a voltage or current threshold. A reference state of the battery is determined (E2) from the state. The no-load voltage in the reference state are measured for separate states of health and a calibration data comprising real values of the state of health/no-load voltage is stored (E7) in an electronic memory.    USE - Method for calibrating a battery of hybrid or electric motor vehicle. Can also be used for calibrating a battery of portable object e.g. laptop, tablet, mobile phone and electronic agenda.    ADVANTAGE - The method enables eliminating requirement of complete charge or discharge of the battery and estimating the state of health of battery in a non-intrusive manner during the use of the battery. The method enables implementing calculations in a phase in a simple manner, without requiring a high computing power, so as to be compatible with an implementation within any device, like a portable object. The method can be easily generalized with any type of batteries, by reproducing the phase of calibration once for each type of batteries. The method enables calibrating the battery in a rapid and non-intrusive manner, with high accuracy. The method can be easily applied in an opportunist way, when the battery is close to the state of reference, without disturbing the normal functioning of the battery.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) a method for estimating a state of health of battery    (2) a computer medium readable by a management unit comprising a computer program including computer program code units to execute a method for estimating a state of health of battery    (3) a device for calibrating a battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart illustrating a method for estimating a state of health of battery. '(Drawing includes non-English language text)'    Step for searching a peak of curve based on quantity of charge of battery (E1)    Step for determining reference state of battery from characteristic state of battery (E2)    Step for positioning battery in state of health (E4)    Step for charging battery, measuring quantity of charge and no load voltage and detecting predefined peak (E5)    Step for continuing charging of battery from identified peak to attain reference state of battery (E6)    Step for storing value of state of health/no-load voltage in electronic memory (E7)