Guides · Updated 2026-11-02

Whole-home backup: battery vs. gas standby generator (plus an installer checklist)

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Short answer: Gas standby generators are best for running a whole house, including central AC and electric appliances, for as long as fuel lasts. Batteries are best for quiet, fume-free backup of your essentials, and they can refill from solar. Many homes do well with a battery for essentials, and some pair it with a generator for long outages.

Two ways to back up a whole home

Gas standby generator

Permanently installed outside, runs on natural gas or propane.
Starts on its own when the power goes out.
Can run large loads like central AC for days, as long as there is fuel.
Needs yearly maintenance and outdoor clearance for exhaust.
Sold and installed through dealers; get local quotes.

Home battery / large power station

Quiet, no fumes, can sit in a garage.
Covers essentials well; runtime depends on battery size.
Can recharge from solar panels, the grid, or a generator.
Bigger models connect through a transfer switch or home panel installed by an electrician.

How much battery is "whole home"?

Battery runtime depends on what you run. Here is roughly how long two larger Anker SOLIX units last on an "essentials" load (fridge, furnace fan part of the time, Wi-Fi, lights, phones, TV, about 300 W average):

Estimated hours running household essentials (~300 W average)

How much it can run at once (steady watts)

Both Anker units can add expansion batteries (the F3000 up to 24 kWh, the F3800 Plus up to 53.8 kWh, per Anker). The F3800 Plus also offers 240 V output for well pumps and larger appliances.

	Anker SOLIX F3000	Anker SOLIX F3800 Plus
Battery size (Wh)	3,072 Wh	3,840 Wh
Steady output	3,600 W	6,000 W
Surge / peak	7,200 W	Not listed
Battery type	LiFePO4	LiFePO4
Warranty	5 yr	5 yr
Weight	91.5 lb	136.7 lb
Price on maker site	$1,499.99	Not listed
Cost per Wh	$0.49	n/a

Specs and prices from each maker's product page, checked 2026-11-02. Prices change often.

Anker SOLIX F3000

Best for: essentials backup in a 120 V home, with wheels so it can move. UL9540 listed, 5-year warranty.

See it on Anker SOLIX's site

Anker SOLIX F3800 Plus

Best for: bigger homes that want 240 V and room to expand toward true whole-home backup. (Sold out on Anker's site when we checked.)

See it on Anker SOLIX's site

Where a portable gas generator fits

A portable inverter generator like the Honda EU2200i (1,800 W rated, about 3.2 hours per tank at full load, per Honda) is a common way to recharge a battery during a long outage. Run it outdoors only, far from windows and doors; it includes a carbon monoxide shutoff called CO-MINDER.

See it on Honda's site

Checklist: questions to ask an installer

Print this or keep it on your phone during quotes.

Which circuits will be backed up: the whole house, or a set of essentials (fridge, furnace fan, well or sump pump, lights, outlets)?
What size do you recommend, and can you show me the load calculation behind it?
Do I need a transfer switch, inlet box or a home power panel, and which one is included in the quote?
Who pulls the permit, and is the inspection included?
For a gas standby: is my gas meter and line big enough, or will the utility need to upgrade it? Who pays for that?
For a battery: how many kWh do I get, how long will it run my essentials, and can solar recharge it during an outage?
Where will it sit? What are the clearance rules from windows, doors and property lines (for gas units, exhaust and carbon monoxide matter)?
How loud is it, and does my HOA or city have noise rules?
What maintenance is needed each year, and what does a service plan cost?
What does the warranty cover (parts, labor, battery capacity), and who do I call?
How does it switch over: automatically, and how long is the gap? Will my CPAP or computer notice?
What is the total price, itemized: equipment, install, electrical work, permits, gas work, pad or mounting?
Are there rebates or tax credits that apply, and will you help with the paperwork?
Are you licensed and insured, and can I see reviews or references from local jobs?

Best for running everything, including central AC, for days: a gas standby generator from a local dealer.
Best for quiet backup of essentials that can recharge from solar: a home battery such as the Anker SOLIX F3000 or F3800 Plus.
Best for long outages on a budget: a battery for essentials plus a portable inverter generator to top it up.

Common questions

Can a battery run my whole house?

Large systems can, but most homes size batteries for essentials. Central AC, electric ranges and dryers use a lot, so they are usually what decides battery size.

Do I need an electrician?

Yes for anything that connects to your home wiring: transfer switches, inlet boxes and home panels must be installed by a licensed electrician, often with a permit.

Is a gas standby generator safe?

When installed to code outdoors with proper clearances, yes. Keep working carbon monoxide alarms inside and follow the maintenance schedule.

Runtimes are estimates (battery Wh × 0.85 ÷ watts). Real results vary with temperature, the age of your appliance and how often its compressor runs. Try your own mix in the calculator.