Morningstar PS-15 Manual

Operation
ProStar Operator’s Manual
35
34
4.0
CAUTION: Equipment Damage
Excessive over-charging and gasing too
vigorously can damage the battery plates
and cause shedding of active material from
the plates. An equalization that is
too high, or too long, can be damaging.
Review the requirements for the particular
battery being used in your system.
Certain battery types benefit from a periodic boost
charge to stir the electrolyte, level the cell Voltages,
and complete the chemical reactions. Equalization
(EQ) charging raises the battery voltage above the
standard absorption voltage so that the electrolyte
gases. The green SOC LED will blink rapidly two (2)
times per second during equalization charging.
The duration of the equalize charge is determined by
the selected battery type. See table 4-1 in this section
for more details. The Equalization Time is defined
as time spent at the equalize set-point. If there is
insufficient charge current to reach the equalization
voltage, the equalization will terminate after an
additional 60 minutes to avoid over-gasing or heating
of the battery.
If the battery requires more time in equalization, with
non-metered versions, manual EQ can be activated
using the push-button (see Section 4.4) to continue for
one or more additional EQ cycles. The Prostar meter,
or MSView software, can also be used to program EQ
timing and duration.
The Equalization set-point is temperature compen-
sated through either the on-board local temperature
sensor, or an optional Remote Temperature Sensor
(RTS).
Why Equalize?
Routine equalization cycles are often vital to the
performance and life of a battery - particularly in
a solar system. During battery discharge, sulfuric
acid is consumed and soft lead sulfate crystals form
on the plates. If the battery remains in a partially
discharged condition, the soft crystals will turn into
hard crystals over time. This process, called “lead
sulfation”, causes the crystals to become harder over
time and more difficult to convert back to soft active
materials. Sulfation from chronic undercharging of the
battery is the leading cause of battery failures in solar
systems. In addition to reducing the battery capacity,
sulfate build-up is the most common cause of buckling
plates and cracked grids. Deep cycle batteries are
particularly susceptible to lead sulfation.
Normal charging of the battery can convert the
sulfate back to the soft active material if the battery
is fully recharged. However, a solar battery is seldom
completely recharged, so the soft lead sulfate crystals
harden over a period of time. Only a long controlled
overcharge, or equalization, at a higher voltage can
reverse the hardening of sulfate crystals.
When to Equalize?
The ideal frequency of equalizations depends on the
battery type (lead-calcium, lead-antimony, etc.), the
depth of discharging, battery age, temperature, and
other factors. One very broad guide is to equalize