Schumacher SF-2254 - Manuel (Page 4)

4
6 VOLT BATTERY
12 VOLT BATTERY
WEAK
GOOD
BAD
SYSTEM
CHARGING
GOOD
20 30
START
40
CHARGING
0 10
Manual operation. Must be monitored.
TIMER: The main function of the timer is to prevent over charg-
ing while allowing a battery time to obtain a satisfactory charge.
To properly set the timer you must know the size of the battery
in ampere hours or reserve capacity in minutes and the state of
charge. Often the state of charge is not known, this is one rea-
son why the timer was limited to 2.25 hours. With the aid of a
battery load tester the state of charge can be obtained within a
few seconds. For example, the average size automotive battery
at a 50% state of charge will require 1 to 1.5 hours of charging
at the 40 amp rate to reach the full charge state. For the same
battery with the timer set to it’s maximum, 2.25 hours, over charg-
ing will occur, but not likely cause harm to a battery that was
other wise in good condition. When the charge state is not known,
start out with a timer setting of 1 hour or less.
HOLD This position defeats the timer function, allowing for con-
tinuous operation. Use when you want to charge more than 2.25
hours. This is normally the case when the 2 amp charge rate is
selected. Be sure to monitor the charging and stop the charge
when the battery is charged.
Rotary switch - Use the rotary switch to select the charge rate
or engine start setting you require. Read the switch dial for those
available on this charger.
The Ammeter indicates the amount of current measured in am-
peres that is being drawn by the battery. For example, In the 40
amp charge rate a typical discharged battery will initially draw
approximately 40 amps. As the battery continues to charge, cur-
rent will taper to 15 to 20 amps at full charge. The Start area of
the meter indicates a high rate of current being drawn from the
charger. When cranking an engine, the starter motor draws up-
wards to 200-300 amps. The meter needle will be at the ex-
treme right side of the start area. Sometimes a battery for the
first few minutes of it’s charge will draw more than 40/60 amps,
in this case the needle may be within but not to the extreme
right side of the start area. The 2 amp charge rate (on some
models) may indicate some activity on the meter. The meter
doesn’t have the resolution to display this low rate.
The Voltmeter indicates the voltage at the battery terminals.
Note that Model SF 2254 is not a Load tester, but a voltmeter.
Use as follows:
1. Charger need not be plugged into AC outlet. Timer should
be in the Off position, 6v/12v switch in position to match
battery being tested, and then connect following instruc-
tions in Section F.
2. Observe the meter indication. Keep in mind that this read-
ing is only a battery voltage reading, a false surface charge
may mislead you. We suggest that you turn on your
headlamps for a couple of minutes before you read the
meter. Read a couple of minutes after you have shut the
headlamps off, then follow the convenient color code of the
meter.
H. OUTPUT SELECTOR CONTROLS