Rolls Surrette User Manual

21
Allow the battery bank to cool for 1-2 hours. Check and record the specific gravity
of each cell. The gravities should be 1.265 ± 0.005 or lower. Check electrolyte levels
and add distilled water as 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.
PREVENTATIVE EQUALIZATION & FREQUENCY
Most multi-phase charge controllers offer pre-programmed Equalization schedules
commonly referred to as preventative equalizations. These are typically set to run for
a shorter 1-2 hour period every 30, 60 or 90 days and may be beneficial in balancing
and removing small amounts of accumulated sulfation on an ongoing basis.
It should be noted that running frequent equalizations on batteries which do not
require balancing or desulfation will overcharge and deteriorate the cells prematurely,
shortening the life of the battery. For this reason, Rolls recommends monitoring
specific gravity and voltage on a regular basis to ensure scheduled Equalization times
are appropriately set. Alternatively, a corrective Equalization may be necessary if
symptoms arise such as running a backup generator more frequently (low capacity) or
the battery bank will “no longer hold a charge”. These symptoms are typical of heavy,
accumulated sulfation. If a battery is not being fully charged on a regular basis or
limited or inadequate Equalization is performed using a generator, sulfating will occur
from “deficit” cycling‘. This undercharge and buildup will gradually lower available
capacity. It is best to monitor the condition of the bank regularly as accumulation of
sulfation may take months to reach a point where the loss is noticeable.
NOTE: Properly charging a battery bank with sufficient voltage and current on each
cycle is essential to long cycle life. Equalizations may be required periodically to
balance and desulfate but should not be relied on to compensate for insufficient
charging sources. This procedure may not fully recover a loss of capacity from a
buildup of sulfation over time. Repeated Equalizations may be required in situations
where the battery bank has been consistently undercharged. Recovered capacity,
generally partial, may take 1-3 months with monitoring and repeated procedures
in battery banks with consistently low specific gravity measurements.