Rolls Battery - Corrective Equalization Method; Specific Gravity Measurement

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Corrective equalization can take a very long time depending on the degree
of sulfation.
1. If you have a recombination cap, remove during equalization.
2. Set the charging controls to the recommended equalization settings according
to voltage.
3. Charge at a low DC current (5 A per 100 AH of battery capacity). If grid power is not
available, use solar panels or a good DC source when possible. At high voltages,
charging with generator can be difficult and hard on the inverter.
4. Once every hour, measure and record the specific gravity and temperature of a test
cell. If the temperature rises above 46ºC and approaches 52ºC, remove the batteries
from charge.
5. If severely sulfated, it may take many hours for the specific gravity to rise.
6. Once the specific gravity begins to rise, the bank voltage will most likely drop, or
the charging current will increase. The charging current may need to be lowered if
temperature approaches 46ºC. If the charge controller was bypassed, it should now
be used or put back in line.
7. Continue measuring the specific gravity until 1.265 is reached.
8. Charge the batteries for another 2 to 3 hours. Add water to maintain the electrolyte
above the plates.
9. Allow bank to cool and check and record the specific gravity of each cell.
The gravities should be 1.265 ± 0.005 or lower. Check the cell electrolyte levels and
add water if necessary.
It is recommended that a specific gravity reading of one pilot cell is measured
and recorded on a regular basis when it is thought that the bank is fully charged.
The measurement should be compared to previous readings. If the measurement is lower
than the previous reading, a longer absorption time and/or higher voltage setting should be
used. The longer the absorption time and the higher the bulk voltage, the more water will be
consumed but less equalization will be required.
Note: The specific gravity should rise as the cells use water. Look for trends in the specific
gravity over a period of time and make small adjustments as necessary.