SU1000NET short runtimes

[eric512_apc]

This was originally posted on APC forums on 10/26/2016

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I have an older (ok really old) 1999 SU1000 Smart-UPS. Put in larger fresh batteries, the 18Ah size. Fit just fine. I expected about 350 watt hours of power from those two 18Ah batteries, but in a recent 50W run test, I only got 100 watt hours. After the run the voltage was down to 22.5V for the pack under load. Fully charged was measured at 27.741V

I've done a run time calibration, and all seems fine. Maybe these are junk batteries? They are SPS12180, which I was told are direct replacements for this unit.

Aloha.