INVO 850VA 450W Line-Interactive UPS with Cold Start

Four hundred and fifty watts covers a router, a modem and a small workstation — enough to stay online and shut down cleanly through a short cut, which is what most homes and small offices actually need rather than an hour of runtime.

Cold start is the feature worth knowing about: it will run off its own battery with no mains present at all, so it works as an emergency supply during a long outage rather than only bridging one. Automatic voltage regulation smooths an unstable supply, and there is surge, overload and short-circuit protection behind it.