Schumacher SE-4220 Battery Charger User Manual


 
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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
selections.
AMMETER: The Ammeter indicates the amount of current mea-
sured in amperes that is being drawn by the battery. For ex-
ample, In the 40 amp charge rate a typical discharged battery
will initially draw approximately 40 amps. As the battery contin-
ues to charge, current 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 upwards to 200 amps. The meter needle will be at
the extreme 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 ex-
treme 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.
H. OUTPUT SELECTOR CONTROLS
VOLT/RATE SELECTOR
CHARGE TIME/MINUTES
12 VOLT/10 AMP
12 VOLT
2 AMP
6 VOLT
40 AMP
100 AMP
START
OFF
12 VOLT
200 AMP
START
12 VOLT
40 AMP
Ammeter