INTRODUCTION
1.2 RANGE ROVER
Battery Voltage
Open Circuit Voltage Test
Before commencing diagnosis of electrical problems, verify the condition of the battery is
acceptable by using the open circuit voltage test.
1. Switch off all electrical loads on the vehicle.
2. Adjust digital multimeter to read dc volts on the appropriate scale.
3. Connect test probes across battery terminals ensuring that polarity is correct and
record the voltage displayed.
A reading of 12.5 V or more is acceptable; any battery which reads less than this will
need charging.
NOTE: If the vehicle has been used within a period of 8 hours prior to the test, surface
charge must be removed from the battery by switching the headlamps on for approximately
30 seconds. Wait a further 60 seconds before checking the open circuit voltage.
Battery voltage is used as a known reference for ascertaining whether or not circuits are
receiving sufficiently high voltage for components to function correctly. This reference is only
a guide since most electronic circuits are designed to function over a wide range of voltages.
In addition, consideration must be given to readings affected by voltage drop across certain
components and fluctuations due to cable lengths.
