The unit was making a humming - buzzing noise and is had a burning smell.

Here is what it says for my laptop+3 monitors, yet when the power flickers(meaning it is off and back on within an instant), it just emits a loud beeping noise and does NOT power any of the devices

It does make an annoying humming noise and smell a bit when the power is out and the battery is in use

We have also accidentally overloaded it with a space heater and the battery responded with a loud beep noise and I remedied quickly

I called OG&E to complain and they told our electricity was terrible (which everyone in town already knows) and they would not accept responsibility for my television issues.