Schumacher SC-8020A owner manual Initial Percent Calculation, Using the built-in alternator tester

•The CHARGED (green) LED will light if a charged battery is tested.

•The CHARGING LED does not light in the battery test mode.

•The connected LED lights when a properly connected battery is de- tected.

•When the tester digital display is set to voltage, the CHARGED and CHARGING LEDs won’t light (it could be testing a battery or an alterna- tor).

14.7INITIAL PERCENT CALCULATION

When a battery % is calculated for the first time after connecting a battery, the digital display will show three dashes (“---”) for a period as long as several seconds while the tester analyzes the battery.

14.8NOTES FOR TESTING BATTERY %

A recently charged battery could have a temporarily high voltage due to what is known as “surface charge.” The voltage of such a battery will gradually drop during the period immediately after the charging system is disengaged. Consequently, the tester could display inconsistent values for such a battery. For a more accurate reading, the surface charge should be removed by temporarily creating a load on the battery, such as by turning on lights or other accessories.

The battery % ranges from 0 to 100.

The battery tester is only designed to test batteries. Testing a device with a rapidly changing voltage could yield unexpected or inaccurate results.

15.using the built-in alternator tester

This battery charger has a built-in alternator tester that displays either an accurate alternator voltage or an estimate of the alternator’s relative output compared to normal alternators. The Alternator % values displayed should be taken as general reference, not precise diagnosis. The alterna- tor tester functions the same as the battery tester (see previous section of this manual for details) with a few differences.

15.1TESTING SEQUENCE

There are three basic steps required to use the SC-8020A as an alternator tester.

1.Connect the battery clamps (see sections 6 and 7).

2.Connect the charger power cord to a 120V AC wall outlet (see section 8).

3.Start the vehicle and turn on the vehicle’s headlights. Read the voltage on the digital display or press the digital display button to set the tester to Alternator % and read the alternator percent.

15.2TESTER STATUS LEDs

When the SC-8020A is operating as an alternator tester, the status LEDs

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