Tektronix Keithley 2651A Reference Manual page 237

Model 2651A High Power System SourceMeter® Instrument Reference Manual Section 4: Theory of operation
In the following figure, as the battery drains, the battery voltage is lowered as shown by the green
arrow. Operation will continue in this direction until the user stops operation or the voltage reaches
the voltage compliance limit line.
Since the battery is a power source, operation in this example is limited by the capability of the
battery to deliver 50 mA (see the following figure).
Figure 88: Considerations when sourcing current and sinking power
2651A-901-01 Rev. C October 2021 4-19