Because of the flat discharge characteristics of modern
lithium technologies (e.g. lithium titanate cells) a precise voltage
measurement in the range of a few millivolt is needed. Additionally
automotive temperature requirements (AEC Q100
Grade 3) from -40 ◦ to 85 ◦ have to be fulfilled. Even if
the batteries themselves do not cover this range, the sensor
must measure temperature with a precision of one degree.
The microcontroller chip on the sensor contains an integrated
diode on chip for temperature estimation. This temperature
diode provides uncalibrated a precision of several degree only.
Important is to calibrate the cells sensors using a regression
methode. Compensation is done by preprocessing in the sensor
controller, see figure 14 [6].