Backup is an in-room, plug-and-play energy storage system that sits between your wall outlet and your critical devices (a "front-of-the-outlet" solution). Under normal conditions it passes grid power straight through to whatever's plugged in while keeping its internal battery topped off. When the grid goes down, it automatically switches to battery power in less than 50 milliseconds so your essential appliances keep running — even if no one is home. When grid power returns, it recharges itself automatically.