Section 8: Rechargeable battery measurements
Model 2450 Interactive SourceMeter® Instrument User's Manual
8-4
2450-900-01 Rev. A / June 2013
Figure 35: Circuit diagram for the battery charge and discharge cycle test
There is no internal connection between protective earth (safety ground) and the LO
terminals of the Model 2450. Therefore, hazardous voltages (more than 30 V
rms
) can appear
on LO terminals. This can occur when the instrument is operating in any mode. To prevent
hazardous voltage from appearing on the LO terminals, connect the LO terminal to
protective earth if your application allows it. You can connect the LO terminal to the chassis
ground terminal on the front panel or the chassis ground screw terminal on the rear panel.
Note that the front-panel terminals are isolated from the rear-panel terminals. Therefore, if
you are using the front-panel terminals, ground to the front-panel LO terminal. If using the
rear-panel terminals, ground to the rear panel LO terminal.
Connect the Force HI and Sense HI output terminals of the Model 2450 to the positive (+) terminal of
the battery. Connect the Sense LO and Force LO outputs to the negative (-) terminal of the battery.
Make sure that when the output of the Model 2450 is turned off, it is set to the high-impedance (High-
Z) output-off state. When the high-impedance output-off state is selected, the output relay opens
when the output is turned off. This prevents the battery from draining when the output is off.
To set the output-off state to high impedance:
1. Press the
MENU
key.
2. In the Source column, select
Settings
.
3. Select the button next to Output Off State and select
High Impedance
.
4. Press the
HOME
key to return to the home screen.
The figure below shows the front-panel connections. You can make these connections with four
insulated banana cables (for example, two sets of the Keithley Instruments Model 8608 High
Performance Clip Lead Set).
