Section 8: Rechargeable battery measurements
Model 2450 Interactive SourceMeter® Instrument User's Manual
8-6
2450-900-01 Rev. A / June 2013
For this test, you will perform the following steps:
•
Reset the instrument.
•
Set the measurement to a 4-wire configuration.
•
Set the instrument to source voltage and measure current.
•
Set the current limit to the current level at which the battery is to be charged or discharged. This
is the load current of the test. Even though the Model 2450 is sourcing voltage, it operates in
constant current mode because it is in current limit until it reaches the desired voltage.
•
Select the high impedance output-off mode, which opens the output relay when the Model 2450
output is turned off. This prevents the battery from draining when it is connected to the instrument
with the output off.
•
Turn on the voltage source readback to enable the Model 2450 to measure the battery voltage as
it is either charging or discharging.
•
Read back the load current, source readback voltage, and the relative timestamp.
•
Monitor the voltage until the battery voltage reaches the desired voltage level and stop the test.
To charge the battery, program the Model 2450 to output a voltage that is equivalent to the voltage
rating of the battery. For example, to charge a 10 V battery, set the Model 2450 to source 10 V. As
the battery fully charges, current decreases until it reaches zero or near zero (battery charged).
To discharge the battery, program the Model 2450 to output a voltage to a lower level than the battery
voltage and set the output-off state to high impedance. In this configuration, the Model 2450 operates
as a sink to discharge the battery. Current from the battery flows into the HI terminal of the Model
2450, resulting in negative current measurements. As the battery discharges, the current stays
constant.
Set up remote communications
This application can be run from any of the supported communication interfaces for the instrument
(GPIB, USB, or ethernet).
The rear-panel connection locations for the remote communication interfaces are shown in the
following figure. For additional information about setting up remote communications, see
(on page 3-1).
Figure 38: Model 2450 remote interface connections
