Here’s Why UPS Batteries Fail

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You might be left facing the risk of vital data loss in case your UPS fails due to a lack of proper maintenance. The failure of your UPS battery is usually the main culprit. To find out the main causes of UPS battery failure, please read on below. We also encourage you to reach out to us if you have any questions.

An open circuit, usually resulting from cell dryout, is the most common mode of failure of a Valve Regulated Lead Acid (VRLA) battery. To power the UPS System DC Bus with a high current, Uninterruptible Power Supply (UPS) systems usually rely on a battery system that is connected in SERIES. The current flowing through the string will therefore break if one of the cells in the string opens up. Simply put, your entire UPS battery set up may end up failing due to the failure of a single battery cell.

Temperature as a Cause of Battery Failure

Temperature fluctuations or incorrect temperature is the most common cause of malfunctions in UPS batteries. Keeping the temperature of the lead acid battery at 22 to 25 degrees Celsius helps ensure that the battery achieves its average shelf life as set by the manufacturer and guarantees performance at an optimum level. If the temperature is over the upper limit, the battery’s life reduces, while its capacity increases; on the other hand, if the temperature goes below the lower limit, the battery is bound to be damaged in addition to underperforming. To put things into perspective, the shelf life is halved every time the temperature goes up by 8 degrees Celsius. As such, you should expect your batteries to only last half of their rated life, which may be five or ten years, in 35 degree Celsius operating temperature.

Eventually All UPS Batteries Die

All UPS batteries die eventually regardless of how well you follow their direction for use. These batteries, as their power delivery capabilities diminish over time, will need to be replaced by new ones bought at a UPS Battery Shop.

Discharge Cycles of UPS Batteries

The amount of recharge and discharge cycles of a UPS battery one of the main causes of a reduction in the life of the battery. The resulting battery life reduction is directly proportional to the level of energy drawn from it during a discharge. The breakdown of the contacts of the battery is the main cause in this case. The premature death of batteries is directly caused by regular discharging. Battery discharge cycles should also include short Uninterruptible Power Supply activity caused by sag and swell compensation.

Testing the battery terminal connection torque regularly, thermal imaging scans for unusual or hot operating conditions, testing the voltage of the battery and visual inspections are some of the effective preventative maintenance steps.

To guarantee reliable operation of your UPS, maintaining and serving your battery regularly is essential. The likelihood of identifying weak batteries before they completely fail as well as removal of corrosion and ensuring the integrity of connections increases with preventative maintenance.


Your UPS batteries are more likely to malfunction when they are neglected. While replacement is necessary over time, regular maintenance is important. You can put your mind at ease, prevent the failure of your UPS battery and also get a better picture of its condition with UPS Systems’ UPS maintenance check. It is possible for you to identify a problematic battery before it causes a collapse of your entire UPS system, and even maximise the battery shelf life with the right maintenance and storage, even if no system can serve you for eternity.