EF EcoFlow has built a reputation for making portable power accessible. The Delta 3 Ultra Plus stands out because it’s a modular foundation. You start with a solid 3072Wh base unit, but the system can expand to over 11kWh with extra batteries. This means your initial investment can grow from handling a weekend outage to powering a week-long off-grid trip.

With 3600W of continuous AC output, it runs like a standard household circuit. You can plug in a refrigerator, a window AC unit, and a set of power tools without it breaking a sweat. The integrated transfer switch is the key feature for home backup. It connects to your home’s electrical panel, so when the grid fails, essential circuits switch over automatically. You don’t need to run extension cords through the house.

Recharging is fast, accepting up to 4000W of solar input. You can realistically refill the entire base unit from the sun in under two hours with enough panels. For a permanent home backup solution, the required high-power solar array and professional installation are a significant additional cost. But as a core power plant, it’s remarkably capable and adaptable.