Schumacher SC1591 Owner's Manual page 8

3. Otherwise, the CAP CHARGING (green) LED will either be flashing or solid, indicating the utlracaps are
charging or charged respectively.
4. Connect the charger to the vehicle battery following the instructions given in Follow These Steps
When Battery is Installed in Vehicle.
5. For best results, wait until the ultracaps are fully charged (see step 1) before pressing the START/STOP
button. When the START/STOP button is pressed, charging of the ultracaps, if active will stop and the display
will show rdy, indicating the charger is ready to detect an engine crank.
6. When the charger detects the engine crank, it will display On and put out maximum power from the
ultracaps. The user can also opt to press and hold the START/STOP button in step 5. This will cause the
charger to instantly display On and put out maximum power from the ultracaps rather than wait to detect an
engine crank.
7. Crank the engine until it starts or the display changes back to percentage of charge, indicating the
ultracaps are being charged by the lithium battery.
8. If the engine did not start, repeat steps 5 through 7.
9. When the lithium battery becomes discharged, it will no longer be capable of charging the ultracaps
and the display will show Chg, and both the CAP CHARGING (green) LED and LITH CHARGING
(green) LED will be off, indicating the unit needs to be connected to AC power to charge the
ultracaps and lithium battery before being used as a portable unit again.
10. Press the START/STOP button to stop engine starting.
11. Press POWER ON/OFF button.
12. Disconnect the battery clamps from the vehicle.
13. Connect the unit to a live grounded 120V AC outlet to charge the internal ultracaps and lithium
battery.
TESTER AND CHARGER MODES
When first connected to an AC outlet, the POWER ON/OFF button is pressed, and after the ultracaps are fully
charged, the unit operates only as a tester, not as a charger. Pressing the START/STOP button deactivates
the tester mode and activates the charger mode. Pressing the START/STOP button again will shut off the
charger mode and activate the tester mode.
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. Connect the charger to a live grounded 120V AC outlet.
3. After the ultracaps are fully charged, the display will change from ultracap percentage of charge to
voltage at the battery clamps and the corresponding PERCENTAGE OF CHARGE (green) LED and
VOLTAGE (green) LED will change as well. Read the voltage on the digital display. Keep in mind that
this reading is only a battery voltage reading; a false surface charge may mislead you. Compare the
reading to the following chart.
12V Battery Voltage Reading 24V Battery Voltage Reading
12.8 or more
12.2 to 12.7
Less than 12.2
NOTE: The battery tester is only designed to test batteries. Testing a device with a rapidly changing
voltage could yield unexpected or inaccurate results.
POWER-UP
When the charger is first powered up (connected to a live, grounded 120V AC outlet and POWER ON/
OFF button pressed), the unit will default to the 30A BOOST rate. Use the RATE selection button to
change this setting. See Section 10.
25.6 or more
24.4 to 25.4
Less than 24.4
• 8 •
Battery Condition
Charged
Needs charging
Discharged