10
The ammeter built into this charger indicates the
amperage that the battery is drawing from the charger.
The meter will read 15 amps if the battery is discharged
and the charger is set on the 12 volt 10, 12, or 15 amp
setting. As the battery charges, the meter will taper back to
around 7 amps. A charger with AUTO ON-OFF
TECHNOLOGY will drop to zero amps and the CHARGE
COMPLETE light will come on when the battery is fully
charged. On the 12 volt 2 amp setting the meter will read
5 amps for a discharged battery and taper back to about ό
amp as it charges.
The 6 volt setting is a constant current setting and the
needle will not move from right to left (not applicable to the
87122).
The BATTERY area in red at the top of the meter should
not be used as a precise measurement of the battery’s
percent of charge. There are differences between charger
models and from battery to battery that prevent it from
accurately representing the actual percent of charge.
Chargers with AUTO ON-OFF TECHNOLOGY will show
100% when fully charged.
E
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g
l
i
s
h
Step 3: Set Volt Selector (Bottom Switch)
Select 6 VOLT for charging and
starting 6 volt batteries used in
automobiles, trucks and farm
equipment. Plug the ac power
cord into the wall outlet.
Select 12 VOLT for charging and starting 12 volt batteries
used in automobiles, lawn tractor, motorcycle, trucks and
farm equipment. Plug the ac power cord into the wall
outlet.
6 VOLT
OFF
12 VOLT
READING THE METER
K
TIME TO CHARGE
L
Manual battery chargers need to be disconnected from a
battery when the battery is fully charged. If this is not
done, the battery will overcharge, resulting in possible
battery damage.
A large automotive battery (65 amp hours or 100 minutes
of reserve capacity) that is completely discharged (lights
will not come on at all) should never take longer than 8
hours to charge on the 12 volt 10 amp setting. Batteries
with a partial charge, smaller batteries, and chargers with
a higher amperage output such as 12 or 15 amps will take
even less time to charge. If the meter shows that the
battery is drawing amperage (from 7–15 amps) and after
charging for up to eight hours, the battery still isn’t fully
charged, have the battery professionally tested or
replaced. On battery chargers equipped with AUTO ON-
OFF TECHNOLOGY, if the meter shows zero amps, then
preactivation of the battery may be required.
The following instructions will allow you to determine how
long it will take to bring a specific battery to full charge. If
the charger is so equipped, a green light on the charger
will indicate the battery has become fully charged.
CAUTION
Batteries that have 25% charge or less can easily freeze
and should be charged at once, but DO NOT CHARGE A
BATTERY THAT IS ALREADY FROZEN.
1. Determine the present level of charge in the battery
with a hydrometer or electronic percent-of-charge
tester.
2. Determine the size of the battery in AMP HOURS or
RESERVE CAPACITY. If these ratings are not printed
on the battery, contact your local battery dealer for this
information. These are the only ratings that can be
used to determine length of charging time. Then use
the formula in step 3 for the charging rate capabilities
of your charger.
3. Use the battery rating, the charge level of the battery,
and the amp setting to be used on the charger, in the
formula provided below.
NOTE: If the battery is rated in RESERVE CAPACITY,
use the following formula to convert reserve capacity to
amp-hours.
Reserve Capacity
2
+
15.5
=
Amp-Hour Rating
EXAMPLE:
Battery's Present State of Charge: 25%
Percent of Charge NEEDED: 100% – 25% = 75%
Expressed as a Decimal: = .75
Amp setting on Charger: 10
Amp-Hour Rating of Battery: 60
60 X .75
10
X 1.25 = Hours to Reach Full Charge
45
10
X 1.25 = Hours to Reach Full Charge
X 1.25 = 5.625 Hours to Reach Full Charge
(5 Hours, 38 Min.)
4.5
Amp Hour
Rating of
Battery
Percent
of Charge
NEEDED
X
Amp Setting Selected
On Charger
X
1.25
=
Hours
to
Charge
