Schumacher SE-4022 - Manual (Page 16)

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Yellow or Red but the needle continues to fall – Indicates the battery may be
defective or rundown. Release the load switch and note the voltmeter reaction.
Voltage recovery into the green or above within seconds indicates a defective
battery. A slow recovery indicates a rundown condition. For best results, check
the specific gravity of the battery.
General Charging Notes
Fan: It is normal for the fan to be on all the time. Keep the area near the
charger clear of obstructions to allow the fan to operate efficiently.
CALCULATING CHARGE TIME 12.
The Hydrometer or Electronic Method
To find the time needed to fully charge your battery, determine the battery’s
charge level with a hydrometer or electronic Percent-of-Charge Tester. The
following table will help you convert hydrometer readings to percent of charge
values.
SPECIFIC GRAVITY PERCENT OF CHARGE PERCENT OF CHARGE
NEEDED
1.265 100% 0%
1.225 75% 25%
1.155 25% 75%
1.120 0% 100%
When you know the percent of charge and the Amp Hour (AH) rating of your
battery, you can calculate the approximate time needed to bring your battery to
a full charge.
To convert Reserve Capacity to Amp Hours, divide Reserve Capacity by 2, and
add 16:
Example:
Amp Hour Rating = Reserve Capacity + 16
2
NOTE: The Reserve Capacity can be obtained from the battery specification
sheet or the owner’s manual.
To calculate the time needed for a charge:
Find the percent of charge needed. (A battery at 50 percent charge that will 1.
be charged to 100 percent needs another 50 percent (.50)).
Multiply the Amp Hour Rating by the charge needed (.50) and divide by the
2.
charge rate.
Multiply the results by 1.25 and you will have the total time needed, in
3.
hours, to bring the battery to full charge.
Add an additional hour for a deep-cycle battery.
4.