The Different Causes of UPS Battery Failure

UPS Systems PLC is capable of providing UPS batteries along with impedance tests and various other kinds of UPS maintenance. You can contact us here.

With improper servicing, your Uninterruptible Power Supply (UPS) can end up failing. This can leave your entire business at risk of losing valuable and important data. The main reason it could happen is due to a failing battery. It might pay to look into a Fiamm battery in the UK. In this article, we will be detailing some of the main causes of a UPS failure. If you have any questions after, feel free to contact us.

Perhaps the most common failure of a VRLA Battery happens to be caused by a cell dry-out. It is when the unit gets an open circuit as a result of the dry-out. UPS systems usually have a SERIES connected battery system that is there to provide the necessary high current to the DC bus of the UPS unit. Therefore, if even one cell throughout the string opens up, it can cause the current to get broken throughout the entire string. Thus, a single failed battery cell can ultimately force your entire infrastructure to collapse singlehandedly.

Battery Failure Temperature

The main reason for the failure of a UPS is improper temperature or the temperature variance being too great. Optimum performance and the average stated lifespan of the manufacturer is typically achieved when the temperature of a lead-acid battery maintains a steady 22 to 25 degree Celcius. Anything lower or higher can cause the battery to under-perform or even sustain damage. The batteries under 22 degrees will end up under-performing, whereas anything over 25 degrees can feature a reduced battery life. As a good guideline to follow, any 8-degree rise in temperature can end up cutting the life of the battery completely in half. Thus, if batteries are operating at 35 degrees, they are only going to end up lasting half of their original expected lifespan.

UPS-Battery-Empty: Batteries Don’t Last Forever

Despite following every single guideline set forth by the manufacturer, you will find UPS batteries not lasting forever. After all, UPS batteries end up losing their inherent ability to deliver the appropriate level of power and they will need to be replaced, at some point.

Discharge Cycle

One of the main factors that can contribute to a reduction in battery life has to do with the total number of battery discharge and recharge cycles it goes through. The total amount of energy that a battery is capable of delivering during discharge is likely to have a direct impact on how much the battery’s lifespan is reduced. The biggest cause of this is due to the contacts of the battery deteriorating. Having to go through constant discharging cycles can cause batteries to wear down and reach the end of their life-cycle before they should have. Any short UPS activity because of the compensation for sags and swells can be seen as discharge cycles.

Having the right preventative maintenance in place can help. This maintenance includes a basic visual inspection, testing the battery’s voltage, and looking at thermal image scans to check for hot or otherwise abnormal conditions. It even includes retesting the torque on the connections of the battery itself. If any of these tests show that the battery has irregularities, it can be determined how critical they are and whether or not they need to be replaced.

Having this type of routine maintenance is crucial to ensuring that you can keep your UPS reliable. This type of preventative maintenance can help minimise the chances you experience a loss from a faulty UPS.


If you don’t take the necessary precautions to look after your battery, they are going to be much more likely to fail. Undergoing routine and preventative maintenance is key to keeping it functioning optimally. A maintenance health check from UPS Systems can give you the details you need to ensure that your system is functioning as it should and to prevent UPS battery failure. While you cannot prevent a UPS battery from failing, there are things you can do to proactively be ahead of the end of its lifespan so you take the necessary precautions to avoid critical data loss.