How often should I change batteries in my UPS Uninterruptible Power Supply?

Posted by alexsaenko 17/03/2017 0 Comment(s)

What is the lifespan of an typical UPS battery and how do I know when to replace it?


Cost and regularity of changing internal batteries in your UPS System is probably one of the most common questions when it comes to maintaining a typical Uninterruptible Power Supply.


In short, the life of UPS internal batteries is almost impossible to predict. It’s common to assume that the batteries will last between 2-5 years given standard operating conditions. There are many factors that can affect the useful life, such as ambient temperature, battery quality, discharge/recharge frequency, humidity, etc.


As a rule of thumb, many manufacturers recommend to have the internal batteries replaced every 2 years to achieve maximum system reliability. That’s is probably why you’ll find that Manufacturer’s Warranty on UPS internal batteries is typically no more than 2 years.


Normally a UPS would perform a periodic self-test to verify that the batteries are still in good order. If it detects that batteries are faulty, the UPS will display a fault signal thereby letting the user know that the batteries need replacement. Consequently, a lot of users choose to wait till the batteries fail before replacing them. Although this might seem as the most cost effective solution, there are few issues at play:


  • Once the internal batteries fail, UPS will not be able to provide any backup time until the batteries are replaced


  • Older batteries (even if they’re still in working condition) will not be able to hold as much charge as the new ones. Hence, the amount of backup time will be less than originally provided


Replacement Battery Type, Quantity and Size


Overwhelming majority of UPS Systems use the sealed lead-acid SLA (also known as VRLA or valve-regulated lead-acid) type of internal batteries. It is currently the most reliable, safe and cost-effective type of battery, hence why it’s so widely used in UPS Systems.


If unsure, it is always best to double check with your UPS Manufacturer or UPS Supplier regarding the type, size, and quantity of internal batteries so they can be safely replaced like-for-like.


Also, with some UPS models the process of replacing batteries is easier than with others. Please refer to the UPS user manual for more details.


In order to avoid injuries, we always recommend to have the internal batteries replaced by properly trained and adequately qualified personnel.


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