Implement Battery Maintenance Best Practices to Ensure Business Continuity
Written by Brandon SchulerJune 23, 2014
The industrial uninterruptible power supply (UPS) is the foundation of an emergency power system. Unlike the commercial UPS designed to protect critical IT loads, the industrial UPS protects critical processes, control systems, and fire/life safety systems. For applications such as oil and gas, petrochemical and power generation plants, when the power is interrupted, it can cause dangerous chemical process instability, damage to process equipment, or in some cases, the complete shutdown of the facility — costing millions in lost product, damaged equipment, and lost production time.
As most of us know, a UPS is only as reliable as the batteries that support it. In fact, it has been reported that nearly 37 percent of down units are due to battery failure. If a power outage occurs, even a single bad cell in a string of batteries could compromise a plant’s entire back-up system, leaving a business without protection.
In order to fully protect a UPS system — and ultimately the entire operation — plant managers should implement prevent maintenance best practices for batteries, which are highlighted in this article, but they must first educate themselves on battery life expectancy.
Battery Life Cycle and Management Strategies
Batteries represent a significant part of the cost of the emergency 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 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 an emergency 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 in which batteries are housed
- The quality of the systems used to maintain the batteries
- Lack of proactive battery maintenance
Typical batteries start to lose capacity within three years depending on usage and environmental conditions, with critical deterioration from the three- to five-year mark.
Nothing can stop the battery-aging process, but there are a few preventive maintenance best practices that plant managers can and should implement in order to optimize the performance of batteries. And with so much at stake, an effective preventive maintenance strategy can be one of the most cost-effective measures you can take to ensure the continuous power to your critical processes and your entire plant.
Four Best Practices for Preventive Battery Maintenance
Preventive maintenance is used to ensure maximum reliability of equipment by providing systematic inspections, detection, and correction of incipient failures, either before they occur or before they develop into major defects that result in costly downtime. Preventive maintenance can include activities such as inspections, tests, measurements, adjustments, parts replacement, and general housekeeping practices.
Maintenance best practices depend on the type of battery a facility is using. For example, flooded or vented lead-acid (VLA) batteries and valve-regulated lead-acid (VRLA) batteries would each require different testing, inspections, and load requirements. The Institute of Electrical and Electronics Engineers (IEEE) has documented these best practices and recommends a schedule as it relates to the criticality of any given application. Plant managers should adhere to these recommendations. It is also important to adhere to battery manufacturer schedules defining specific battery maintenance checks. The following are best practices that can be implemented with all battery types.
- Ready-to-Install Batteries and Proper Installation
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, and environmentally), and their condition verified in order to minimize the likelihood of costly retests and equipment damage.
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, plant managers may experience schedule delays or extra costs to replace or repair damaged components. - Battery Monitoring
Battery monitoring can significantly reduce the risk of process instability due to battery failure, optimize battery life, and improve safety. One recent study of organizations with service contracts and regular preventive maintenance schedules found that businesses that implemented battery monitoring experienced half as many battery failures as businesses 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 using a direct current test 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. 
Monitoring Combined with Remote Services
Most plant managers understand the importance of battery monitoring but have a plethora of other responsibilities for which they are responsible. 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.
In these cases, remote monitoring coupled with proactive maintenance and remote services can be an easy solution. Not only does remote battery monitoring lift the burden from internal personnel, but in many cases, it also integrates on-site and remote preventive maintenance activities with predictive analysis to identify problems before they occur.
These remote services may also include a team of engineers reviewing the battery information. This typically includes written algorithms that allow engineers to predict cell failures days in advance and take steps to avoid a malfunction.
Other benefits of remote services include these:- Staying ahead of the curve – In addition to improved resource utilization, a dedicated monitoring organization can respond more quickly to battery issues. For instance, in monitoring data at multiple locations, the monitoring organization may be alerted to a problem caused by a certain manufacturer’s battery. Very quickly, the manufacturer can be notified so as to avoid a potential problem occurring at other plants that may contain similar equipment.
- 24/7 data – Remote monitoring uses 24/7 technology, providing constant flow of data. This data is used as a diagnostic tool to look at relationships between different battery readings, providing real-time notification when a problem occurs.
- Manage systems – Remote monitoring enables the service partner to control systems remotely where authorized. This is particularly valuable when a plant is undergoing changes and updates.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.
- 4. On-Site Spares
Having quick access to spare batteries that have been aged along with your main battery string makes replacement faster and more stable. While it’s impossible to replicate the exact 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.
Other advantages of keeping on-site spare batteries include the following:- 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.
As operations place more and more emphasis on business continuity and the reliability of emergency power systems, plant 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 start with having knowledge of a battery’s life cycle. Plant managers then need to follow battery maintenance best practices as defined by IEEE and battery manufacturers. It is recommended to adhere to these best practices with additional focus on proper installation of ready-to-install batteries; monitoring, preferably combined with remote services; and keeping on-site spares. Devoting attention proactively and continuously to the battery system will help organizations ensure their critical operations remain up and running.
Brandon Shuler is supervising engineer for data center services at Electrical Reliability Services, Emerson Network Power and has more than 16 years of experience in performing and managing electrical/electronics testing and maintenance.
