Smart UPS self-test fail

[BillP]

This question was originally posted by harry on APC forums on 8/24/2016

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Hi,

I have a model SUA3000RMI2U UPS and it reported that one of the battery failed during the self-test

However, after 2 weeks, it did another self-test and it reported everything ok, even the red LED for battery is gone

Do I still need to change battery for that?

[MarkC_apc]

This was originally posted on APC forums on 8/24/2016

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My experience with the SUA/SU RM models are that one "weak" battery (you have four in series with 2 parallel sets - total of 😎 will often pass the startup test (that stresses the battery system briefly) only if they are all fully charged (several hours on charge cycle at 100%).  If they have just come off a discharge cycle, will fail the test.  Sounds likely that you have at least one battery that is "weak".  

Hope this helps

[BillP]

This reply was originally posted by harry on APC forums on 8/24/2016

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hi mark,

you are right that it is a weak battery that caused the failure. in this case, do i need to change the battery since the self test has passed after two weeks. or is it a symptom that the battery is going bad and i should change it since it is already 3 years, please advice thanks

[MarkC_apc · Accepted solution]

This was originally posted on APC forums on 8/25/2016

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Depends - if your backup is very critical (industrial data) - replace all batteries with new.  If it is personal use and you can learn how to calibrate and load test the batteries on a periodic basis - find the weak battery and replace it.  You might get another year or two from the remaining batteries.  I do this frequently - especially on these units as the batteries are easy to access and replace.  On the SMX units - no so much!!  Learn battery handling safety - no rings and use the thin neoprene gloves.