Most homeowners shopping for battery backup do not need whole-home coverage, and most of the systems we review are built for exactly that smaller job: a fridge, some lights, a router, maybe a window AC. Whole-home coverage is a different, more expensive category, because it means the system has to carry your heaviest circuits at the same time your panel would normally split that load across two legs of 240V service. As of this writing, the EcoFlow DELTA Pro 3 and the Anker SOLIX F3800 are the only portable power stations that clear that bar from a single unit. This guide walks through whether you actually need that scope, then breaks down how to choose between the two.

Is Whole-Home Coverage the Right Scope for You?

Before comparing products, it is worth confirming you are shopping in the right category. Whole-home backup makes sense when losing power means losing something that cannot wait: a well pump in a house with no gravity-fed water, central AC in a climate where a multi-day outage during a heat wave is a real health risk, or medical equipment that draws more than a small unit can carry. If your real concern is keeping the fridge cold and the lights on for a night or two, a smaller, cheaper system covers that job without the 240V requirement, and our home battery backup systems guide covers that full range, including four lower-cost options alongside the two systems here.

It is also worth asking whether battery backup is the right technology at all, versus a gas generator. Generators cost less upfront and run as long as you have fuel, but they need maintenance, they run loud enough to disturb a quiet neighborhood, and they cannot go indoors. A battery system switches over silently in milliseconds and needs nothing but a wall outlet or sun to recharge. Our generator vs. battery backup guide breaks down that tradeoff in full; the short version is that batteries tend to win on convenience and noise, generators tend to win on raw runtime during long, sunless outages, and a fair number of households end up using both together.

The Two Systems Built for This

Both units deliver 120V/240V split-phase output from a single box, which is the specific feature that makes whole-home coverage possible without hardwiring in a second unit. For a full spec-by-spec breakdown of where each one pulls ahead, see our dedicated DELTA Pro 3 vs. F3800 comparison. This guide focuses on the whole-home decision specifically: how much panel load you actually need to cover, what integrating either system into your electrical panel involves, and which one fits a given household’s setup.

What to Check Before You Buy

Add up your critical-circuit wattage first

Whole-home does not have to mean every circuit in the house running at once. Walk your panel and total the running wattage of what actually needs to survive an outage together: central AC compressor, well pump, refrigerator, a few circuits of lighting, and anything medical. A 3-ton central AC draws roughly 3,500 to 4,500 running watts on startup surge and less on steady run; a typical well pump draws 1,000 to 2,000W. Both systems here clear a combined load in that range, but if your household runs a larger AC unit, an electric dryer, and a well pump simultaneously, lean toward the F3800’s higher 6,000W ceiling.

Plan for a transfer switch or smart panel, and an electrician

Neither of these units backs up your whole home just by being plugged into a wall outlet. Getting circuit-level, automatic backup requires a transfer switch or a compatible smart panel (EcoFlow’s Smart Home Panel 2 for the DELTA Pro 3, Anker’s Home Power Panel for the F3800), installed by a licensed electrician. Budget for that installation cost separately from the unit price; it typically runs from several hundred to a couple thousand dollars depending on your panel’s condition and how many circuits you want managed individually.

Decide if you will ever need to expand

Both units start well short of a multi-day whole-home runtime on their base battery alone and are designed to be expanded. The F3800 has the higher ceiling at 53.8 kWh versus the DELTA Pro 3’s 48 kWh, though both numbers are large enough that most households will never fully build out either stack. What matters more in practice is whether you want to spread that cost over time, buying the base unit now and adding batteries as your budget allows, or you know upfront you want maximum runtime and would rather buy the capacity in one purchase.

Factor in solar if you want to ride out a long outage

A whole-home system without solar input still runs out eventually; with rooftop or portable solar keeping pace, it can run indefinitely. The DELTA Pro 3 accepts slightly more solar input at 2,600W against the F3800’s 2,400W, a modest edge. The bigger differentiator is that the F3800 supports AC coupling with existing grid-tied rooftop solar, letting it cycle daily for cost savings even outside an outage, while the DELTA Pro 3 is built around its own dedicated PV input rather than integrating with a home’s existing solar array.

Our Picks

How to Decide

Start from your panel, not the spec sheet

The single most useful thing you can do before buying either system is add up the running wattage of the circuits you actually want backed up, then compare that number against each unit’s continuous output rather than its peak or surge rating. A household that undersizes this step ends up with a system that trips or underperforms exactly when it matters most.

Get the installation quoted alongside the unit

Because whole-home coverage depends on a transfer switch or smart panel and a licensed electrician, price that installation before you commit to either unit. It is a real part of the total cost, and availability can affect how soon the system is actually usable after it arrives.

Weigh price against headroom

The F3800 costs less than the DELTA Pro 3 while delivering more continuous output and a higher expansion ceiling; the DELTA Pro 3 costs more but pairs with a more established smart-panel ecosystem and carries UL9540 certification. Neither is a wrong choice for most whole-home setups. If your panel load fits well under 4,000W, the price gap is the more relevant factor; if it does not, the F3800’s extra headroom is worth the closer look regardless of price.

If your critical load is smaller than what either of these systems is built for, our home battery backup systems guide covers four additional systems built for essential-circuit backup at a lower price. If a generator is still on the table, our generator vs. battery backup guide walks through that tradeoff directly. And if you have narrowed things down to these two and want every spec compared side by side, our DELTA Pro 3 vs. F3800 comparison goes deeper than the table above.

Frequently Asked Questions