Using The Voltmeter To Test Battery State Of Charge; Battery Percent And Charge Time - Schumacher Electric DSR125 Manuel D'utilisation

13. USING THE VOLTMETER TO TEST BATTERY STATE OF CHARGE

OVERVIEW
The charger has a built in voltmeter to test your battery's state of charge. The charger does not have
a built in load tester. As such, 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 eventually 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 by turning on the lights or other accessories.
The battery tester is only designed to test 6V and 12V batteries. Testing a device with a rapidly changing
voltage could yield unexpected or inaccurate results.
TESTING SEQUENCE
There are three basic steps required to test the battery state of charge:
1. Connect the battery charger's clips to the battery. Be sure to follow all of the precautions listed under
sections 6 and 7.
2. Connect the charger's power cord to a 120 VAC outlet. Again, be sure to follow all of the precautions
listed under sections 6 and 7.
3. Read the voltage on the digital meter or press the Display Mode button to set the tester to Battery %
and read the battery percentage.
TESTER AND CHARGER
When first turned on, the charger operates only as a tester, not as a charger. To continue to use it as only
a tester, avoid pressing the START/STOP button. The charger is always in tester mode until the START/
STOP button is pressed. Pressing the START/STOP button activates the charger and deactivates the tester
TESTING AFTER CHARGING
After the unit has been changed from tester to charger (by pressing the START/STOP button), it remains
a charger as long as it's connected to a battery. Press the START/STOP button again to change back to
tester mode.

14. BATTERY PERCENT AND CHARGE TIME

This charger adjusts the charging time in order to charge the battery completely, efficiently and safely.
The duration of the charging process depends on three factors:
Battery State
If a battery has only been slightly discharged, it can be charged in less than a few hours. The same battery
could take up to 10 hours if very weak. The battery state can be estimated by using the built-in tester. The
lower the reading, the longer charging will take.
Battery Rating
A higher rated battery will take longer to charge than a lower rated battery under the same conditions. A battery
is rated in Ampere-Hours (AH), Reserve Capacity (RC) and Cold Cranking Amps (CCA). The lower the rating,
the faster the battery will charge.
Battery Size
The charger automatically selects a charge rate up to 10 amps. The charger charges at the selected charge
rate and eventually reduces the charge rate in a controlled manner. After the charging process has started,
the digital display can be used to determine the charging progress by selecting the % (Battery %) mode.
Important facts to keep in mind when charging a battery:
• When the display indicates 77% charged, the battery has been charged enough to start most vehicles.
• After connecting to a battery, the battery % shown in tester mode is an estimate based on the battery
voltage and a scale set by the Battery Council International. The battery % shown in charger mode is
an estimate of the relative charge in the battery compared to the charge it should have if the charging
process is allowed to complete.
• The battery % shown in tester mode can be used to estimate the relative charge time. The lower the %
shown, the longer the charge time for a given battery.
• The battery % shown in charger mode is an indication of the relative progress of the charging process. The
higher the battery % displayed, the less charge time remains.
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