Schumacher SC1591 Owner's Manual page 7

ENGINE STARTING WHEN CONNECTED TO AN AC OUTLET
NOTE: If you have charged the battery and it still will not start your car, do not use the Engine Start
feature, or it could damage the vehicle's electrical system. Have the battery checked.
1. With the charger unplugged from the AC outlet, connect the charger to the battery following the
instructions given in Follow These Steps When Battery is Installed in Vehicle.
2. Connect the charger to a live grounded 120V AC outlet.
3. With the charger plugged in and connected to the battery and chassis, press the POWER ON/OFF
button, then press the RATE selection button until the ENGINE START (green) LED is solid, and then
press the START/STOP button.
4. Crank the engine until it starts or 5 seconds pass. Do not crank during the cool down period (see
below). This allows the charger and battery to cool down. NOTE: During extremely cold weather, or
if the battery is under 2 volts, charge the battery for 5 minutes before cranking the engine.
5. If the engine fails to start, charge the battery for 5 more minutes before attempting to crank the engine again.
6. After the engine starts, unplug the AC power cord before disconnecting the battery clamps from the vehicle.
7. Clean and store the charger in a dry location.
NOTE: If the engine does turn over but never starts, there is not a problem with the starting system;
there is a problem somewhere else with the vehicle. STOP cranking the engine until the other problem has
been diagnosed and corrected.
ENGINE STARTING NOTES
During the starting sequence listed above, the charger is set to one of four states:
• Wait for ready – The charger charges the battery for 2 minutes before the wait for cranking state. While
waiting for ready, the digital display shows On and the engine can be cranked. For severely discharged
batteries, it is not recommended to crank during this time.
• Wait for cranking – The charger waits until the engine is actually being cranked before delivering the amps
for engine start. While waiting for cranking, the digital display shows rdy.
• Cranking – When cranking is detected, the charger will automatically deliver up to its maximum output as
required by the starting system for up to 5 seconds.
• Cool down – After a 3-minute ready period, the charger enters a mandatory 3 minute (180 second)
cool down state. The digital display indicates the remaining cool down time in seconds. It starts at 180
and counts down to 0. After 3 minutes, the digital display will change from displaying the countdown to
displaying rdy. After 2 hours of engine starting, the unit will automatically reset to Tester mode, just as
if the START/STOP button had been pressed.
ENGINE STARTING WHEN NOT CONNECTED TO AN AC OUTLET
Your battery charger is equipped with internal ultra-capacitors, called ultracaps, which can be charged
to store electrical energy that enable it to be used as an engine starter even if not connected to an AC
outlet. When not connected to an AC outlet, the ultracaps are charged by an internal lithium (Li) battery.
When connected to an AC outlet, the ultracaps are charged by AC power. Charging the ultracaps from
AC power is significantly faster than charging from the internal lithium battery, especially if the ultracaps
are almost completely discharged. For this reason, it is recommended that before the unit is used while
disconnected from AC power, that you disconnect the clamps from the vehicle battery, and plug the unit
into AC power, waiting to ensure both the ultracaps and internal lithium battery are fully charged. This is
indicated when the corresponding LEDs on the front panel are illuminated and not flashing. If this is not
the case, and neither LED is flashing, and the unit has been plugged in for more than a day, unplug the
unit and then plug back into AC power to reset the charging.
1. Press the POWER ON/OFF button. The ENGINE START (green) LED will light. If the ultracaps need
charging, they will be charged by the internal lithium battery and the display will show a percentage
of charge for the ultracaps. When the ultracaps' percentage of charge reaches 100 percent, the
display will change to show the voltage at the clamps, illuminating the VOLTAGE (green) LED.
NOTE: ENGINE START is the only rate selection when not connected to an AC outlet. Battery
charging using 6A CHARGE or 30A BOOST rates is not allowed.
2. If the display shows Chg, 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.
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