As the lifeblood of any uninterruptible power supply (UPS), the batteries represent the heart of the system. Yet research shows that up to 20 percent of all UPS failures can be attributed to bad batteries. To help extend the life of your UPS batteries ― and protect your organization from the significant costs and harmful consequences of unexpected downtime ― it is important to recognize the elements that influence the lifespan and reliability of UPS batteries, as well as the steps you can take to prolong the life of your UPS.
1. Understand Your Batteries
UPS battery life and battery performance are impacted by many factors, one of which is chemistry. There are two primary types of battery chemistry that comprise today’s UPS systems: valve-regulated lead acid (VRLA) batteries and lithium-ion batteries. Regardless of the type of battery or how well it is maintained, all batteries have a useful life and will eventually need to be replaced. On average, lead acid batteries deliver a lifespan of three to five years, while Li-ion batteries generally last eight to 10 years.
The cycling process also impacts UPS battery life. During a utility power failure, a UPS does its job by switching to battery power in order to keep connected equipment up and running. However, once utility power is restored, the battery goes through a charging cycle, where it is recharged for future use. Each time the battery is discharged and recharged, its capacity is slightly reduced. The more often a unit cycles, the more its lifespan is reduced.
2. Manage Battery Temperature
The temperature at which a UPS battery is stored and operated is another factor that can dramatically impact its longevity. The rated capacity of a UPS battery is based on an ambient temperature of 77°F; varying from this recommended temperature can significantly impact battery performance, as well as dramatically shorten the life of the battery.
To help determine battery life in relation to temperature, consider that for every 15°F average annual temperature above 77°F, the life of the battery is reduced by 50 percent. While maintaining ambient temperature may not be an issue for UPS units deployed within air-conditioned data centers, it can be a problem in other environments such as industrial locations and manufacturing sites. In addition, when installing a UPS unit, it is advised to leave at least 2 inches of space on each side in order to facilitate proper airflow. You should also avoid placing a UPS near open windows or in high-moisture areas.
Users who fail to properly maintain climate control in the room or rooms where the UPS and batteries are installed run a high risk of decreasing the life of their UPS batteries and ultimately leaving their critical load vulnerable during a power event. Failure to maintain batteries at their recommended ambient temperature can even void your UPS and battery warranty. Most manufacturers require appropriate documentation to verify temperature for any claim, and usually specify that failure to maintain the recommended temperature range will invalidate the warranty.
3. Maintain Your Batteries
Another critical aspect to extending battery service life is engaging in regular preventive maintenance. Without it, a UPS battery becomes susceptible to a number of threats that can ultimately result in a reduced level of protection and premature failure. Even batteries that are labeled “maintenance-free” still require periodic checkups. During regularly scheduled UPS battery maintenance visits, trained technicians perform a number of inspections, including visually scrutinizing batteries, racks or cabinets for signs of corrosion and leakage; measuring the float voltage and current of the entire bank; recording the terminal voltage of selected batteries; checking the electrolyte level of wet cells; noting the ambient temperature; and comparing the findings against previous battery maintenance inspections.
Performing regular maintenance helps to accurately estimate the end of battery life, which in turn enables scheduled replacement without unexpected downtime or loss of backup power. In addition, preventive maintenance helps extend the life of battery strings, providing the opportunity to detect loose connections, remove corrosion and isolate bad batteries before they affect the entire string. Finally, gradual decreases in battery life can be monitored and evaluated through periodic voltage assessments and load testing completed during a PM visit.
4. Recharge Stored Batteries
While many organizations elect to keep a stock of replacement batteries on hand in the event of a premature or unexpected battery failure, it is important to avoid storing replacement batteries for longer than six months without charging. Batteries that are left on the shelf for extended periods are much more likely to have a shorter lifespan.
When a UPS battery is stored for an extended period, several factors can affect its performance and longevity. The most significant concern is the potential for the battery to deteriorate, leading to reduced performance and lifespan. One of the primary factors that can impact stored batteries is self-discharge. All batteries gradually lose their charge over time, and this is especially true for lead-acid batteries. Yet if the battery is left sitting unused for a long time, it can lose its charge, which can cause it to become sulfated, leading to permanent damage and reduced performance. Another factor that can impact a stored UPS battery is temperature. To maximize the life expectancy of stored batteries, be sure to keep them in a cool, dry place.
UPS batteries that have lost their charge can be connected to a temporary feed for recharging. When not installed on an active charging system (UPS or external charger), batteries should be recharged at a minimum of every six months, but preferably every three months. In some cases, external battery charging systems can be brought in to perform a refreshening charge. Regardless, a discharged battery must be recharged within 48 hours of the discharge to avoid permanent battery damage. Storing a UPS with the battery connected can cause permanent battery damage within a few days to a week, depending on the UPS.
5. Recycle Dead Batteries
No matter how pristinely UPS batteries are cared for, they will nonetheless require replacement at some point. That’s because they are electrochemical energy storage devices that convert chemical energy into the electrical energy that UPSs use to operate, and over time the chemicals deplete. As a result, batteries will deliver less power and for shorter periods of time. Even if you follow all guidelines for proper storage, usage and maintenance, batteries still have limited life and will usually exhibit a slow degradation of capacity until they reach 80 percent of their initial rating, followed by a comparatively rapid failure.
Recycling UPS batteries enables their parts to be reused for the creation of new batteries ― helping to support a cleaner, more sustainable environment. Look for a UPS service provider that offers a process to return and recycle all batteries. Discarded electronic equipment is accumulating quickly in the industrialized world and without effective collection, reuse and recycling systems, these devices will prove to be more than our waste management systems can handle.
Build a Resilient UPS System With Unified Power
At Unified Power, we understand the importance of properly maintained UPS batteries. We offer full and partial battery replacement services on all major manufacturers’ batteries, including new batteries, load bank testing and miscellaneous hardware to ensure reliable connections. Find out more about our comprehensive range of battery services, which are designed to help you extend UPS battery life and the overall longevity of your UPS system.
In addition, we recycle both flooded and sealed batteries at national EPA-certified recycling centers, with chain of custody/recycling certificates provided to customers for every battery. All services are performed by our team of highly trained technicians in accordance with IEEE standards. As part of our commitment to participating in improved recycling efforts, Unified Power encourages all of our customers to return end-of-life UPSs and batteries for recycling and a potential credit toward new equipment. Learn more about how we can help with your UPS battery recycling needs.