Types Of Battery Charges - Yale 524150797 Maintenance Manual

2240 YRM 0001
battery manufacturer. A fully charged battery will have
a specific gravity of 1.265 to 1.310 at 25°C (77°F). See
Figure 15. NEVER charge a battery at a rate that will
raise the electrolyte temperature above 49°C (120°F).
Never let a battery stay discharged for long periods.

Types of Battery Charges

1. NORMAL CHARGE. This charge is usually given
to a battery that is discharged from normal
operation. This is often an 8-hour charge. Many
customers charge the battery at regular intervals
that depend on use. This procedure will keep the
battery correctly charged if the battery is not
discharged below the limit. Always use a
hydrometer to check the battery if the battery is
charged at regular intervals. Frequent charging of
a battery that has a 2/3 or more charge can
decrease the life of the battery.
2. EQUALIZING CHARGE. This charge is at a low
rate and balances the charge in all the cells. The
equalizing charge is usually given approximately
once a month. It is a charge at a slow rate for 3 to
6 hours in addition to the regular charging cycle.
Do not give an equalizing charge more than once
a week. The most accurate specific gravity
measurements for a charged battery will be after
an equalizing charge. If the specific gravity
difference is more than 0.020 between cells of the
battery after an equalizing charge, there can be a
damaged cell. Consult your battery dealer.
NOTE: Many customers have battery chargers that
can follow a program to automatically charge a battery
according to recommendations of the battery
manufacturer. Use the recommendations of the battery
manufacturer for charging the battery.
When performing a monthly equalization charge it is
recommended to check individual cell voltages.
Complete an equalization charge.
1
Measure and compare the voltage for each cell.
2
Record any cells differing more than 0.5 volts
3
from other cells.
4 Calculation the
(average cell voltage -0.845 = specific gravity).
For example 2.09 volts - 0.845 = 1.24.
Verify calculated specific gravity by performing a
5
specific gravity measurement of each cell with a
hydrometer.
The discharge limits and the limits for the specific
gravity before the battery must be charged again are
expected specific gravity
shown in Figure 17. NEVER discharge a battery below
the limits shown in Figure 18. Discharging a battery
beyond the design limits will decrease the service life
of the battery.
NOTE: Sometimes the capacity of a battery is not
enough to complete a work period. Check for the
following conditions:
The battery is too small for the job.
•
The battery is not fully charged.
•
The battery charger is not operating correctly.
•
The battery is near the end of its service life.
•
Figure 17. Specific Gravity Versus Percent
Discharge
Battery Maintenance
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