SMT: Battery capacity after self-test

[MysteryGuy_apc]

This was originally posted on APC forums on 10/31/2017

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Hi;

  I got a brand new SMT1500 tower UPS yesterday. I set it up about 20 hours ago and installed the Power chute business edition 9.2.1 'Web Agent' software.

After running a self-test today at about 45.5 % load, the 'battery capacity' reported (on the Agent web page) dropped from 100% to 82%. The voltage reported dropped from 27.2 V to 25.4 V for about 30 seconds before returning to 27.2 V.

The reported run-time remaining at 45.4 % load dropped from 27 minutes to 21 minutes.

After about 25 minutes the battery capacity returned to being reported as 100%.

Is this normal (at least as far as the % battery charge goes)? I wasn't expecting such a large drop.

I'm not sure how comparable it is, but I have an old SU1400 with a 6 month old battery. When I ran a self-test at 21% load, it reported 99% battery capacity immediately afterwards (27.76 V). If I remember correctly, that unit seems to only report a noticeably lower percent remaining (after a self-test) when the battery is getting old.

My new SMT1500 appears to have been tested 5/31/17, so I assume it's been sitting for about 5 months before I got it in case that's relevant. Before the self-test, the UPS was reporting that it was in 'green' mode.

Does this seem like the expected behavior for a 'new' battery? Since the papers that came with the unit seem to say that the battery should have at least 90% charge after 3 hours, it seemed like 20 hours would have been enough charge time.

Thanks;