03 August 2015
By Marco Da Silva, Managing Director for
Power Solutions, The Jasco Group
Power problems are a reality in South Africa
for the foreseeable future, and many organisations have already implemented
solutions to minimise downtime and ensure business can continue as close to
normal as possible. Common equipment to enable this includes Uninterrupted
Power Supply’s (UPS’) with battery backup that benefits in a number of
scenarios. This type of system either provides enough time to safely shutdown
equipment that may be damaged by sudden power cuts, bridges the power gap for
the switch to generator power, or powers critical equipment for a few hours. The
battery is essential to the successful use of such a failsafe, however, what
many organisations forget is that no battery lasts forever, and they have a
limited lifespan before they must be replaced. If the battery fails, the entire
backup power solution is at risk. It is therefore critical to monitor the
health of batteries to ensure your battery backup will not leave you in the
lurch when you need it most.
Batteries have a limited lifespan and can only
be used a certain number of times before they will cease to hold a charge,
which means they will be unable to perform their intended function. General
wear and tear and usage will also inevitably deplete a battery’s capability,
and the general expected life of a UPS battery is typically between three and
five years as a result. However, the life expectancy of the battery is greatly
affected by a number of factors, which can be controlled to ensure you get
maximum usage from your battery. Failing to account for these factors can also
cause premature battery failure, leading backup solutions to fail themselves,
often at the most inopportune moment.
The physical location or environment of the
UPS battery is an important consideration. A temperature-controlled environment
is ideal, as temperature can have a significant effect on the life of a
battery. In addition, the UPS should ideally not be located in areas of high
humidity, very dusty environments, or areas where it may be exposed to
corrosive chemicals or fumes. Ventilation is important, and the openings on all
sides of the UPS must not be covered.
As mentioned, temperature is a critical factor
when considering UPS batteries, specifically the ambient temperature in which
the battery is located. Most UPS batteries are lead acid batteries, which
operate best at an ambient temperature of 25 degrees Celsius. Keeping the UPS
in an environment that is as close as possible to this ideal will maximise its
life expectancy. If the temperature is too high, the battery will bulge, damaging
the cells, resulting in the requirement to replace them. If the battery is kept
at a consistently low temperature, the cells will begin to crystallise. Both
scenarios result in degraded performance and a reduced life span over time.
Poor charging practices can also negatively
impact a battery’s life expectancy, as both over charging and under charging
can affect performance. The recommended charging time of most UPS batteries is
10 hours, however suppliers may undersize chargers in an effort to save costs.
While this will bring down the initial price of the solution, it will cost more
in the long term, as batteries will need to be replaced more frequently.
UPS system design is critical in 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 is 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, including hospitals, financial institutions and security
organisations amongst others, it is recommended that a permanent online
monitoring solution be installed on all batteries. Such a solution is
self-contained, meaning it 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 by the
second in order 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, the approach and
technology algorithms allow one to forecast risks. This ensures that battery
backup is continuously maintained to optimal levels, and will never fail
without warning, preventing the potentially catastrophic consequences of such
an event.