EmersonNetworkPower.com
What You Need to Know About
Your Critical Infrastructure
Liebert Services eBook Series
Chapter Four
Battery Life
Executive Summary
Batteries Are Critical to Your UPS
Battery Life Expectancy
What Causes Premature Battery
Failure?
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Remote Monitoring
When Do Batteries Need to be
Replaced?
Always Keep Spare Batteries Onsite
Conclusion
EmersonNetworkPower.com
Chapter Four
Battery Life
Executive Summary
Executive Summary
In our last chapter, we addressed preventive maintenance for power and cooling, discussed
Batteries Are Critical to Your UPS
why it is critically important to a data center, and offered a preventive maintenance checklist for
Battery Life Expectancy
power and cooling systems. In this chapter, we hone in on batteries – a critical piece of every
data center – and discuss how they should be monitored and maintained.
What Causes Premature Battery
Failure?
Batteries are Critical to Your UPS
How to Optimize Battery
Performance
In our previous chapters, we talked about how
Battery Maintenance Best
Practices
a UPS system is critical to a data center. Tests
and assessments and preventive maintenance
Battery Monitoring
programs are often implemented in a data center
Remote Monitoring
to maintain and protect these systems, but in
When Do Batteries Need to be
Replaced?
reality, a UPS is only as reliable as the batteries
that support it. In fact, it has been reported
Always Keep Spare Batteries Onsite
that nearly 37 percent of down units are due to
battery failure.
Your UPS is only as reliable as its batteries.
Conclusion
If a power outage occurs, even a single bad cell in a string of batteries could compromise a
facility’s entire backup system, leaving an organization without protection.
In order to fully protect a UPS system – and ultimately the entire data center – managers must
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educate themselves on batteries. This includes a knowledge of battery life expectancy, battery
monitoring, and battery replacement.
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Chapter Four
Battery Life
Executive Summary
Batteries Are Critical to Your UPS
Battery Life Expectancy
What Causes Premature Battery
Failure?
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Remote Monitoring
When Do Batteries Need to be
Replaced?
Maintenance is the single largest difference between normal battery life and premature failure.
Battery Life Expectancy
Always Keep Spare Batteries Onsite
Conclusion
Batteries represent a significant part of the cost of the critical power system, but are subject to
wear and aging faster than most other components.
Batteries have a certain life expectancy and, sooner or later, every battery will reach the end of
its life. Misunderstanding battery life expectancy is common and stems from confusing battery
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design life with battery service life.
Battery design life is specified by the manufacturer and takes into account cell design and battery
aging under controlled conditions in the manufacturer’s laboratory. Battery service life considers
how application, installation design, real-world operating conditions and maintenance practices
impact battery aging — most often lowering life expectancy.
Whether the batteries supporting a critical power system will age normally toward their defined
life cycle or fail prematurely depends on a variety of factors, including:
How batteries are handled
The environment they’re housed in
The quality of the systems used to maintain the batteries
Lack of proactive battery maintenance
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Chapter Four
Battery Life
What Causes Premature Battery Failure?
Executive Summary
Other factors that can cause premature battery failure include:
Batteries Are Critical to Your UPS
High or low charge voltage
Battery Life Expectancy
Excessive charge current
What Causes Premature Battery
Failure?
Strained battery terminals
Manufacturing defects
How to Optimize Battery
Performance
Improper room temperature
Overcharging and over cycling
Battery Maintenance Best
Practices
Loose connections
Strained battery terminals
Battery Monitoring
Manufacturing defects
Remote Monitoring
Poor & improper maintenance
Click here to watch battery
maintenance and monitoring video.
When Do Batteries Need to be
Replaced?
Always Keep Spare Batteries Onsite
How to Optimize Battery Performance
Conclusion
Nothing can stop the battery aging process, but there are a few things data center managers can
and should do to optimize the performance of batteries in their facility without placing operations in jeopardy due to a potentially failing cell, and that begins with adopting proactive battery
management strategies such as:
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Follow battery maintenance best practices outlined
by IEEE standards and battery manufacturer schedules
defining specific battery maintenance checks and how
frequently they should be made.
Monitor batteries to continually assess the health of
your power system’s life support without incurring
maintenance downtime.
Keep onsite spares at the same life stage to avoid
catastrophic loss caused by replacing too many of the cells
in a string during normal battery lifetime.
Perform capacity testing in accordance with IEEE
recommended practices to verify battery integrity.
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Chapter Four
Battery Life
Executive Summary
Batteries Are Critical to Your UPS
Battery Life Expectancy
What Causes Premature Battery
Failure?
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Skilled technicians can provide recommendations that will guarantee battery availability.
Remote Monitoring
Battery Maintenance Best Practices
When Do Batteries Need to be
Replaced?
The first line of defense in guarding against battery failure
happens before batteries are placed in service. Batteries need
to be fully charged, properly installed — physically, electrically
Always Keep Spare Batteries Onsite
Conclusion
and environmentally — and their condition verified in order
to minimize the likelihood of costly retests and equipment
damage.
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Properly inspecting the batteries before startup and/or load
testing will provide valuable information that can be applied
immediately and serve as a baseline for any testing conducted
throughout the service life of the batteries.
If this basic information is not collected, analyzed and understood, there is no guarantee the
batteries will perform as needed and trend analysis becomes more difficult. If an abnormality
goes undetected, data center managers may experience schedule delays or extra costs to replace
or repair damaged components.
Maintenance best practices also depend on the type of battery a facility is using. For example,
flooded batteries and VRLA batteries would each require different testing, inspections, and load
requirements. The IEEE has documented these best practices and recommends a schedule as it
relates to the criticality of any given application.
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Chapter Four
Battery Life
Executive Summary
Batteries Are Critical to Your UPS
Battery Life Expectancy
What Causes Premature Battery
Failure?
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Combining on-site visits with trending and diagnostics helps you identify problems before they become serious.
Remote Monitoring
Battery Monitoring
When Do Batteries Need to be
Replaced?
As we previously mentioned, battery failure is the number one cause of UPS system dropped
Always Keep Spare Batteries Onsite
loads. To protect against battery failure – and ultimately expensive downtime – data center
managers should implement a dedicated battery monitoring system.
Conclusion
Battery monitoring can significantly reduce the risk of dropped loads due to battery failure,
optimize battery life, and improve safety. A recent Liebert Services study of organizations with
service contracts and regular preventive maintenance schedules found that customers who
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implemented battery monitoring experienced half as many battery failures as customers that
didn’t.
The best practice is to implement a monitoring system that connects to and tracks the health
of each battery within a string, but the most effective battery monitoring systems continuously
track all battery parameters, including internal resistance, using a DC test current to ensure
measurement accuracy and repeatability.
A battery monitoring system provides a continuous watch of the battery to assess its true
state of health. Instead of waiting for an inevitable failure or replacing batteries prematurely to
prevent problems, battery monitors allow organizations to continue to utilize their batteries
longer and with confidence by knowing the true condition of all critical battery parameters, such
as cell voltage, internal resistance, cycle history, overall string voltage, current and temperature.
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Chapter Four
Battery Life
Executive Summary
Batteries Are Critical to Your UPS
Battery Life Expectancy
What Causes Premature Battery
Failure?
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Remote monitoring exposes the unknown threat of failing batteries to maximize system availability.
Remote Monitoring
Remote Monitoring
When Do Batteries Need to be
Replaced?
Most data center managers understand the importance of battery monitoring, but as we
Always Keep Spare Batteries Onsite
discussed in our first chapter, rapid changes in the IT industry have given managers a “full plate”
Conclusion
of responsibilities in terms of running an efficient, available and optimized facility, and battery
monitoring either falls to the bottom of the list of priorities, or in some cases, organizations don’t
have enough internal personnel to dedicate someone to this task.
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In these cases, remote monitoring, managed by an organization with resources devoted to
battery monitoring, can be an easy solution. Not only does remote monitoring lift the burden of
infrastructure monitoring from internal personnel, but in many cases, it also integrates onsite and
remote preventive maintenance activities with predictive analysis to identify problems before they
occur – and it can all be done in real-time.
A remote monitoring service may also include a team of engineers reviewing the information. This
typically includes written algorithms that allow technicians to be proactive rather than reactive so
engineers can predict cell failures days in advance and take steps to avoid a malfunction. There’s
an inherent benefit in having a centralized expert group that can do that type of detailed analysis
and proactively react to it. If a problem occurs, they can immediately alert the situation, dispatch
a technician, diagnose the problem, stabilize the situation, and alleviate the problem prior to
deterioration or failure, while also gaining availability all at the same time.
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Chapter Four
Battery Life
Other benefits of remote monitoring include:
Use batteries longer and with confidence – Instead of waiting for an inevitable failure or
Executive Summary
Batteries Are Critical to Your UPS
replacing batteries prematurely to prevent problems, battery monitors allow organizations
Battery Life Expectancy
to continue to use their batteries longer by knowing the true condition of all critical battery
What Causes Premature Battery
Failure?
parameters such as cell voltage, internal resistance, cycle history, overall string voltage,
current and temperature.
Stay ahead of the curve – In addition to improved resource utilization, a dedicated
monitoring organization can respond more quickly to portfolio issues. For instance, in
monitoring data across multiple facilities, they may be alerted to a problem caused by a
certain manufacturer’s breaker. Very quickly, the manufacturer can be notified so as to
avoid a potential problem occurring across hundreds of sites, many of which contain similar
equipment.
24/7 Data – Remote monitoring uses 24/7 technology, providing constant data to a facility.
This data is used as a diagnostic tool to look at relationships between different battery
readings, providing real-time notification when a problem occurs.
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Remote Monitoring
When Do Batteries Need to be
Replaced?
Always Keep Spare Batteries Onsite
Conclusion
Manage Systems – Remote monitoring enables remote management of systems (where
authorized), allowing the monitoring partner to control systems remotely. This is particularly
valuable when a facility is undergoing changes and updates.
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While there are many battery monitoring services available, the best solution to maximizing battery
performance is to utilize an integrated battery monitoring service that combines state-of-the-art
battery monitoring technology with proactive maintenance and service response.
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Chapter Four
Battery Life
Executive Summary
Batteries Are Critical to Your UPS
Battery Life Expectancy
What Causes Premature Battery
Failure?
How to Optimize Battery
Performance
Battery Maintenance Best
Practices
Battery Monitoring
Remote Monitoring
When Do Batteries Need to be
Replaced?
Always Keep Spare Batteries Onsite
If valve regulated lead acid (VRLA) batteries have been in service for four or more years, they should be evaluated
to ensure that your UPS system will provide the protection you require.
Conclusion
When Do Batteries Need to Be Replaced?
Service life of a battery is limited and depends on many factors, including age, usage,
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environment and maintenance. IEEE standards recommend replacing a battery at the time its
capacity drops below 80 percent.
A typical VRLA battery may start to lose capacity or fail within three to five years. Proactively
replacing batteries will help keep a system running up to specifications and minimize the risk of
costly downtime to operations.
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Chapter Four
Battery Life
Always Keep Spare Batteries Onsite
Executive Summary
It is recommended that data centers have enough spare
Batteries Are Critical to Your UPS
batteries to cover five to 10 percent of the batteries
Battery Life Expectancy
(depending on battery type) in every cabinet, depending
What Causes Premature Battery
Failure?
on the criticality of the facility, plugged in and housed
similarly to the batteries in service. The spare batteries will
How to Optimize Battery
Performance
age simultaneously with the main battery string, making
replacement faster and more stable. While it’s impossible
Battery Maintenance Best
Practices
to replicate the exact same conditions, replacing a failing
battery with one of the same age, even if some variance in
the condition of batteries exists, is safer than replacing it
with a new battery.
Proper storage of spare batteries will
also maximize the service life of the
individual battery.
Other advantages of keeping onsite spare batteries include:
Spare batteries will be charged and ready when they are needed most
Batteries will age with the original battery string, eliminating the risk of a mismatch
The number of visits to repair a battery string is reduced
The risk of obsolescence for both VLA or VRLA batteries is minimized
Conclusion
As business reliance on data center systems increases and more emphasis is placed on availability
and reliability of critical power systems, data center managers need to understand that without
properly operating batteries, no UPS system can do its job.
Strategies to maximize the availability and performance of battery systems include following
battery maintenance best practices, monitoring batteries, and keeping spares onsite. Devoting
attention proactively to the battery system will help organizations ensure their business critical
systems remain up and running.
Liebert Services is committed to helping organizations understand their critical infrastructure,
identify problems, and incorporate solutions. Stay tuned for chapter five in our eBook “What You
Need to Know about Your Critical Infrastructure” to learn more about what data center managers
should look for in a service provider, with a specific focus on safety, training and compliance.
Emerson Network Power | What You Need to Know About Your Critical Infrastructure
Battery Monitoring
Remote Monitoring
When Do Batteries Need to be
Replaced?
Always Keep Spare Batteries Onsite
Conclusion