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

[Charles Lepple]

On Dec 2, 2018, at 7:55 PM, raul <raulvior.bcn at gmail.com> wrote:
> 
> I have taken out the batteries and measured them with a multimeter. They put out 13V (they are rated 12V 9Ah).

What sort of load did you have in parallel with the multimeter? (This is why Wolfy mentioned the light bulb: if the battery has developed excessive internal resistance, it will show proper voltages when tested open-circuit, but will read lower with a load.)

> Putting them back again and disconnecting the UPS from the mains it is kept on, powering all the connected devices.
> The shutdowns only occur when the UPS is being monitored. Are you sure it's a battery problem? Do UPS perform further tests when they are being polled for data? I'll check with newer batteries then. I bought these one year ago :S
> 
Hard to say what the UPS firmware does internally - the NUT driver just sends the standard HID queries at the configured polling rates. The reason why I keep bringing up potential hardware issues is that MGE was very open with their standards, and the drivers were extensively tested against hardware from that era.

You sent some debug output earlier - did that include the point at which the UPS shut down? If not, that would be useful information.