Outage transfer is effectively instantaneous in real use. Routers, servers, PCs, and other connected devices generally stay online without a visible interruption.
Pros: rated output, output stability
Cons: over-voltage protection, cold-weather performance
Transfer to battery power is exceptionally quick, with measured or reported switching around 9-20ms. Routers, computers, printers, and networking gear generally stayed online without rebooting.
Pros: surge capacity, voltage regulation
Cons: water resistance, ventilation requirements
The roughly 10ms switchover was frequently described as seamless, with connected electronics continuing without a visible interruption.
Pros: rated output, peak output
Cons: startup reliability, full-load noise