Schumacher SF 4020 Battery Charger User Manual


 
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H. OUTPUT SELECTOR CONTROLS
TIMER: The main function of the timer is to prevent over charging
while allowing a battery time to obtain a satisfactory charge. To prop-
erly 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 reason 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 maxi-
mum, 2.25 hours, over charging 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 continu-
ous 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 bat-
tery is charged.
Switch #1 use this switch to select the 200 amp engine start and
the 40 amp charge rate. Switch #2 must be in the down position
(40amp /200 amp select) when using switch #1.
Switch #2 Use this switch to select the 2 amp charge rate. Also use
to select use of switch #1.
BATTERY
TEST
6 VOLT
12 VOLT
BATTERY
TEST
LOAD ON
6 VOLT
12 VOLT
Ammeter
Voltmeter
SF 8050
SF 2001
SF 4020
Ammeter
Ammeter
SF 6030
Ammeter
CHARGE RATE CHARGE TIME/MINUTES
200 amp start 2 amp
40 amp 40 amp
200 amp
VOLT/RATE SELECTOR CHARGE TIME/MINUTES
VOLT/RATE SELECTOR CHARGE TIME/MINUTES
SF 4022
Ammeter
Voltmeter
#1
#2
12 VOLT
MAINTAINER
6 VOLT
40 AMP/
100 AMP
START
OFF
12 VOLT
200 AMP
START
12 VOLT
10 AMP
6 VOLT
50 AMP
OFF
12 VOLT
40 AMP
6 VOLT
40AMP/
100 AMP
START
12 VOLT
2 AMP
12 VOLT
300 AMP
START
12 VOLT
30 AMP
OFF
12 VOLT
60 AMP
6 VOLT
30 AMP
VOLT/RATE SELECTOR CHARGE TIME/MINUTES
6 VOLT
60 AMP/200 AMP
START
12 VOLT
300 AMP
START
12 VOLT
30 AMP
OFF
12 VOLT
60 AMP
6 VOLT
30 AMP
6 VOLT
60 AMP/200 AMP
START
VOLT/RATE SELECTOR CHARGE TIME/MINUTES
12 VOLT/10 AMP
6 VOLT/40 AMP START
Rotary switch - Use the rotary switch (volt / rate selector, on all
models except the SF 2001) to select the charge rate or engine
start setting you require. Read the switch dial for those available on
this charger.
Load Tester Switch (on SF 8050 only)
Use this switch to apply load to the battery.
Follow these easy steps:
1. Select the correct setting of the meter ( 6v or 12v ) to agree with
the battery to be tested.
2. Connect the charger leads to the battery following the instruc-
tions in section F.
3. Press the Load Switch to load on for 10 seconds and read the
voltmeter.
Good (green)
- indicates the battery capacity is OK. Battery may or
may not be fully charged. Check the specific gravity of battery to
determine the state of charge. If the specific gravity is less than full
charge, check for electrical drain or possible charging system trouble.
Recharge battery to full level.
Yellow or Red, but needle remains steady
- indicates that the
battery capacity is not satisfactory. Battery may be either defective
or not fully charged. Check specific gravity to see which condition
exists. It charging does not bring the battery specific gravity to full
charge, the battery should be replaced.
Yellow or Red, but needle remains falling
- indicates the battery
may be defective or run down. Release the load switch and note
voltmeter reaction. Voltage recovery into green or above within sec-
onds indicates a defective battery. Slow recovery indicates run down
condition. For best results, check specific gravity.
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 ap-
proximately 40 amps. As the battery continues 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-
300 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 40/50 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 4022 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 be-
ing tested, and then connect following instructions in Section F.
2. Observe the meter indication. Keep in mind that this reading is
only a battery voltage reading, a false surface charge may mis-
lead 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.
12 VOLT
40 AMP
(Range: .5-1AMP)