UPS

A UPS (uninterruptible power supply) keeps the node running from a battery when the power goes out. virgoOS watches it, shows its state on the Dashboard, and shuts the node down cleanly before the battery runs out. There is nothing to configure.

Which UPS the node uses

• Built-in: a node that has its own UPS inside uses that one.
• USB: a node without a built-in UPS uses a UPS connected to one of its USB ports. It has to be a USB HID model. Plug it in at any time: it is picked up on its own, with no restart. Unplug it, and the node goes back to having no UPS.

A USB UPS only helps when the node’s power cable is plugged into one of its battery-backed outlets.

On the Dashboard

The UPS row of the Status column shows where the node’s power comes from and how charged the battery is.

• GRID, in green: the node runs from the wall socket. The bar shows the battery’s charge, and moves while the battery is charging.
• BATTERY, in orange: the power is out and the node runs from the battery. The bar turns orange and shows what is left.

• not found, in red: the node has no UPS. It works as usual, but a power cut turns it off on the spot.

• can’t connect: the service that watches the UPS is not answering. Check on Services that virgo-ups is running.

• Any other message, in orange: the UPS answered, but its reading could not be used. The message says why.

A built-in UPS that supports it is not kept at 100%. Charging stops above 97% and starts again below 90%, so a charge anywhere in between with the node on grid power is normal.

During a power cut

1. The node switches to the battery and the Dashboard shows BATTERY. Everything keeps working.
2. If the power comes back, the Dashboard shows GRID again and the battery recharges.
3. If it does not, the node shuts down once the battery is down to 50%. It is an ordinary, orderly shutdown, so nothing is cut off mid-write.

The 50% level is fixed.

A built-in UPS is checked once more a few seconds before the shutdown, so power that returns at the last moment cancels it. After the node has shut down, the built-in UPS turns itself off too, which keeps what is left of the battery.

On a node with a built-in UPS, the virgo-ups service’s log records each switch between grid and battery, and the shutdown when it starts one.