Schumacher SWI-1555A Owner's Manual page 43

Using the Battery Voltage Tester
1. With the charger unplugged from the AC outlet, connect the charger to the battery
following the instructions given in sections 6 and 7.
2. Plug the charger AC power cord into the AC outlet, following the instructions given in
section 8.
3. Place the Function switch in the down position.
4. Make sure the LED on the timer is next to the OFF (O)
5. Read the voltage on the digital display or press the Display Mode button to set the
tester to BATTERY % to read the voltage as a percent of charge. Compare the
voltage reading to the chart below.
12 Volt Battery Reading
Tester and Charger: When first turned on, the unit operates only as a tester, not as
a charger. To continue to use it only as a tester, avoid pressing the AUTO
or the TIMER button
battery charger and deactivates the tester.
Testing After Charging: To change the battery charger back to a tester, press the Timer
button until the LED next to the OFF position is lit. Then press the Display button
until the VOLTS LED is lit.
Using the Alternator Performance Tester
1. With the charger unplugged from the AC outlet, connect the charger to the battery
following the instructions given in sections 6 and 7.
2. Plug the charger AC power cord into the AC outlet, following the instructions given in
section 8.
3. Place the Function switch in the down position.
4. Make sure the LED on the timer is next to the OFF (O)
5. Start the vehicle and turn on the vehicle's headlights. Read the voltage on the digital
display. Compare the voltage reading to the chart below.
12 Volt Alternator Reading
14.6 or More
13.5 to 14.5
Less than 13.4
12.8 or More
12.2 to 12.7
Less than 12.2
. Selecting a time or pressing the AUTO
Battery Condition
Charged
Needs Charging
Discharged
Alternator Condition
Have it checked
Working
Have it checked
• 42 •
position.
activates the
position.
button