TECH TALK
blocks. As most deep-cycle batteries
are typically ‘maintenance-free’, as
they are either sealed or semi-sealed,
there is nowhere for the gases to vent.
This causes a gas build-up, distorting
the battery housing and permanently
damaging the battery.
If the battery is floated on too low a
voltage, the individual cells will not
be chemically stimulated correctly,
can cause a reduction of capacity
and internal sulphation of the cells.
Ultimately the electrolyte fluid becomes
less able to conduct the charge current,
and eventually one will be unable to
recharge the battery block.
UPS systems with battery backup are the most commonly used solutions for South
Africa’s power problems
“Most standby
batteries are
performance rated
at 20 0 C. For every
10 0 C that the
battery operates
at above the
20 0 C mark, a
half-life ageing
takes place.”
Kevin Norris, Consulting Solutions
Architect, the Jasco Group
be months between discharges, which
means that there is very little activity
taking place within the individual
battery cell chemistry. This can result
in cell impedances differing slightly
between each other and, as a result,
cells accepting a different charge
current from each other. Or, over the
multiple number of battery blocks that
make up a UPS battery bank, some
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INTELLIGENTCIO
battery blocks will be at a higher voltage
and some at a lower voltage, which, if
left unattended, could result in some
battery blocks overcharging and some
undercharging. In both cases, if left
unmanaged, the battery block will fail
during discharge, and the UPS will be
unable to provide continuity of supply
during critical power failure periods.
On the opposite scale, if the battery
bank is floated at too high a voltage
for too long a period, the battery blocks
will start to gas and overheat, resulting
in permanent damage to the battery
Proper UPS system design is critical
to ensuring maximum functionality
is achieved. In fact, a poorly designed
system could destroy the batteries in as
little as a few months, and since a battery
is around half of the total cost of a UPS
solution, this can be a costly error.
In addition to correctly designed
systems, it is also essential to
ensure that batteries are proactively
monitored and maintained in order
to address any issues before they can
become problematic. For applications
where uptime is mission critical, such
as for hospitals, financial institutions
and security organisations, it is
recommended that a permanent online
monitoring solution be installed on all
batteries. These solutions are self-
contained, meaning they will not be
influenced by other equipment, and
will manage and measure all relevant
aspects of the battery, proactively
sending out alerts to possible failures
or issues.
Permanent, proactive battery
monitoring solutions make use of
historical data that is continuously
monitored, to assess the status of
the quality of the batteries in the
field. By applying this methodology,
one can immediately determine the
risk associated with the possibility
of batteries failing. This ensures
that battery backup is continuously
maintained at optimal levels, and
will never fail without warning,
preventing the potentially catastrophic
consequences of such an event. n
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