[Nut-upsuser] MGE EllipseMAX 1500 shuts down after a few hours

Charles Lepple clepple at gmail.com
Sun Dec 2 22:50:44 GMT 2018

On Dec 2, 2018, at 3:21 PM, Manuel Wolfshant <wolfy at nobugconsulting.ro> wrote:
> On December 2, 2018 7:29:38 PM GMT+02:00, raul <raulvior.bcn at gmail.com> wrote:
>> I have restored original configuration and enabled the ignorelb flag. I
>> didn't point out in the original e-mail that after every poweroff the 
>> battery percentage is reported at 40% instead of 100% and charges 
>> slowly again to 100%. Maybe the UPS sends a LB event and shuts down 
>> immediatly as suggested in the manual. But the UPS powered off again.
>> The variables reported by upsc can be found here: 
>> https://pastebin.com/JWmnp8iW
>> Graphs plotting the battery charge can be found here: 
>> https://screenshots.firefox.com/iyTY8fAIB2MjXMV5/openmediavault.local
>> The battery charge drops suddenly when the UPS shuts down. 
> Maybe I am completely wrong but this behaviour rhymes quite well with a faulty (old) battery which reports being charged but actually cannot really hold the charge. I suggest taking it off and verifying it with a voltmeter , preferably while having a consumer connected as well ( like a good old 12V incandescent light bulb, as those used for cars i.e. 25-45W or so )

Agreed - my previous emails were assuming that the battery can hold a charge, and pass a self-test. If the UPS performs a self-test, and the battery voltage drops below the UPS low-battery threshold before the microcontroller can cancel the test, it will look like an uncontrolled shutdown. "ignorelb" cannot prevent this.

A little more explanation on "ignorelb": it prevents NUT from trusting the LB flag that the UPS sends. This is really meant for simple UPSes which do not allow adjustment of the LB threshold (almost all MGE/Eaton models do; see the "battery.charge.low" setting in "upsrw"). NUT still needs to determine some threshold for shutdown, and this is typically provided in ups.conf with some "override.*" settings. See https://networkupstools.org/docs/man/ups.conf.html for more details.

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