ammeter reading is three times the ampere-hour rating
of the battery. An example is 180 amperes for a
60-ampere-hour battery. With the tester ammeter
reading the specified load for 15 seconds, note the
voltmeter reading. A reading of 9.5 volts or more for a
12-volt battery and 18.5 volts for a 24-volt battery
indicates ample capacity.
Voltage Drop (Resistance) Tests
High resistance or an open circuit in the starting
Figure 6-72.--Tester connections for a battery capacity test.
system can be located by using an accurate,
expanded-scale voltmeter to check the voltage drop
Set the tester voltmeter scale selector switch to a
across various points.
scale position higher than the voltage of the battery to
be tested; set the load control knob of the tester to the
If the vehicle to be tested is gasoline powered,
remove the ignition coil high-tension lead from the
distributor and ground it (standard ignition), or ground
the primary distributor terminal of the coil
(transistorized ignition) to prevent the engine from
starting while you are making the voltage drop tests.
If connection to the battery is made with the
load control in any position other than OFF, severe
NOTE: The voltage readings (drops) used here are
arcing may occur at the battery posts. If this
general averages and are not to be used in place of the
happens, a battery explosion with injury to
vehicle manufacturer's specifications.
personnel is a possibility.
The following six tests are used to test starting
systems equipped with solenoid-operated overrunning
Connect the battery-starter tester as shown in figure
clutch-type starters (fig. 6-73).
6-72. Turn the load control knob clockwise until the