UPS - Self Test Passed but Battery Only Last for 1 Minute

Hi all,

I have a CyberPower CP900EPFCLCD UPS since 2018, and recently I have done a self test and it shown a passed result.
But then the battery only last a minute or so (under low load: 32watt).

I totally understand that it will need a new battery; the question is, is it normal to have a passed self-test in a UPS, even though the battery is not at full potential?

Also, when it did the self-test, it also disconnected my appliances, from memory, it was not the case with a different UPS brand (such as APC).


  • +2

    I don't think the tests actually apply any load to the battery. At least you bought one that is user replaceable and you can order a new battery.

  • +3

    It's unlikely that these style UPS self test even looks at the battery except perhaps current voltage. 3 years is fairly type normal battery life. As for disconnecting appliances during test that's not surprising. Manual should confirm if it's normal or not.

  • +1

    Yep, that's normal behaviour unfortunately

    Best testing method is actually doing a manual cutoff every few months to see if the UPS performs as expected. If it doesn't last/fails/overloaded under normal loads then you can't trust it to work in an unexpected blackout.

    UPS batteries are cheap though - 9Ah (same size as the 7Ah ones) can be had for $30ish although quality may vary. Yours will only take one, but some bigger UPSs run at 24v and use two in series.

    • Can you think of a suitable battery for my model? As I couldn't find local stock anywhere so far…

      • +1

        I've had good experience with these:

        Seller also was good when I needed to return items, unlike Lanplus who didn't accept a warranty claim even though I was well within the 12 months

        • Thanks for your reply!
          Do you have a similar UPS model too?

          I wonder whether there is a bigger Amperage with similar battery dimension size (15.09cm L X 9.4cm H X 6.5cm W)

          • @BigLeviathan: It turns out, there is no bigger amperage, otherwise it'll be bigger dimension.

          • +1

            @BigLeviathan: that is a 9Ah that is the same size as your battery

  • Thanks for everyone's reply; got the replacement battery now; I suspect there is nothing I can do about this battery apart from send it to the tip? (e.g. I won't be able to 'recharge' it and sell it again)

    • +1

      You can recycle it. Battery world stores will take them and there may be other options depending on where you are. Even a lot of scrap metal places will take them.

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