Section 4: Measurement optimization
Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual
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077114601 / March 2019
ESR measurement
You can measure battery resistance (ESR) only when the 2281S is using the battery test function.
Introduction to the ESR measurement
The following figure shows a battery under test simplified as a resistance with constant voltage.
During charging and discharging, its voltage and resistance change based on the charging of the
SOC. Usually during charging, the voltage only goes up and the resistance only goes down. During
discharge, the voltage only goes down and the resistance only goes up.
Figure 111: Battery equivalent
In the figure above, Voc is the open circuit voltage. ESR represents the battery resistance. Voc plus
the voltage change (up or down) during charging or discharging is Vt.
