APC UPS Self-Test Failed — How to Fix

What Does This Error Mean?

APC UPS Self-Test Failed means the battery delivered less than the required load during the automatic test. The UPS will still condition power and block surges, but will not protect equipment when mains power fails. Replace the battery as soon as possible.

Affected Models

APC Back-UPS BE and BX series
APC Back-UPS Pro BR and BN series
APC Smart-UPS SMT and SMX series
APC Easy-UPS BV series

Common Causes

Battery has reached end of service life — sealed lead-acid batteries last 3–5 years
Battery was not fully recharged before the self-test ran
Battery terminals corroded — preventing full current delivery
Battery cell failure from repeated deep discharges or heat exposure
High ambient temperature above 25°C accelerating battery degradation

How to Fix It

Check the battery age.

Look at the date sticker on the battery or check the manufacture date in APC PowerChute software (Events log). Most sealed lead-acid batteries in UPS units last 3–5 years. If the battery is older than 4 years, replacement is the correct fix.
Let the UPS charge for 24 hours before re-testing.

If the UPS recently ran on battery during a power outage, the battery may not be fully recharged yet. Leave the UPS plugged in for 24 hours, then manually trigger a self-test by holding the test button for 3 seconds or using PowerChute.
Inspect the battery terminals for corrosion.

If comfortable opening the UPS, check the spade connectors where the battery cables attach. White or greenish powder indicates corrosion. Lightly sand the connectors and reconnect firmly — poor contact causes self-tests to fail even on a good battery.
Replace the battery.

Order the correct APC Replacement Battery Cartridge (RBC) by your UPS model number. Search 'APC RBC [your model]'. Official APC RBC packs and reputable third-party equivalents both work. After replacement, charge for 24 hours before testing.

When to Call a Professional

If a brand-new replacement battery still fails the self-test after 24 hours of charging, the UPS charging circuit may be faulty. Contact APC support with the model and serial number.

Frequently Asked Questions

How often should I replace my APC UPS battery?

APC recommends replacing the battery every 3–5 years or when the Self-Test Failed indicator appears. Running an annual manual self-test helps catch battery degradation before a real outage.

Will the Self-Test Failed warning clear after replacing the battery?

Yes. Once the new battery has charged for 24 hours, run a manual self-test. If the battery passes, the warning clears automatically.