What is the expected life of my APC UPS VRLA battery?

For example, a battery expected to last 4 years at 25°C (77°F) would only last about 2 years if operated at 33°C (95°F).

Keep in mind that the internal battery temperature of a UPS is always higher than the ambient room temperature. Because of this, it is strongly recommended to install the UPS in a location with good airflow, proper ventilation, and adequate cooling to help maximize battery life.

You should perform runtime calibrations on your UPS only once or twice per year, and only if truly necessary. While some customers run calibrations to verify that their available runtime is sufficient, performing these tests too frequently can significantly shorten the lifespan of the APC battery.

It is also important to remember that a UPS is not designed for frequent deep‑discharge cycles. We do not recommend using an APC Smart‑UPS or Back‑UPS as a portable power source that is repeatedly discharged and recharged (for example, when mounted on a mobile equipment cart). These units are specifically engineered for emergency backup power during unexpected outages or brief power interruptions—not for continuous cycling like a portable battery pack.

APC batteries should not be stored for extended periods of time. New batteries or UPS units should be stored for no longer than 6 months from the date of purchase, as they leave the factory at approximately 80% charge. After this period, the battery should be placed into use; otherwise, it will lose a significant portion of its charge.

It is also not recommended to store batteries that have already been in use. Long‑term storage without periodic recharging can lead to reduced lifespan and unpredictable performance.

Temperature and Storage Recommendations

Storage temperature has a major impact on how quickly a battery degrades while not in use:

• –15°C to +30°C (5°F to 86°F):
  Perform a full recharge cycle at least every 6 months.

• +30°C to +45°C (86°F to 113°F):
  Perform a full recharge cycle at least every 3 months.

Proper storage temperature and periodic recharging are essential to preserving battery health and ensuring reliable performance when the UPS is finally placed into service.

As the load on your UPS increases, the available runtime decreases. For best performance and battery longevity, it is recommended not to exceed 80% of the UPS’s rated capacity.

If a power outage occurs while the UPS is operating at or near full load, the battery will discharge much more quickly, reducing the amount of backup time available. Frequent heavy loads and rapid discharges can also significantly shorten the battery’s overall life expectancy.

As a VRLA (AGM) battery ages, it undergoes a chemical process known as sulfation. This occurs when lead sulfate crystals harden on the battery plates, reducing the battery’s ability to charge and discharge efficiently.

This can lead to several noticeable effects:

• Longer charging times than normal
• Excessive heat buildup, which can eventually cause electrolyte “boil‑out”
• Shorter runtimes between charges
• Significantly reduced overall battery life

For selected single‑phase Smart‑UPS models, it is recommended to update the UPS firmware to the latest available version. This ensures the unit benefits from all battery‑related enhancements, stability improvements, and performance optimizations provided by APC.

For instructions and compatibility details, refer to FA164737, which outlines the process for updating firmware on supported single‑phase Smart‑UPS units.