What kind of battery backup do you need?

The short answer

For a router or a computer, a UPS gives you minutes to a few hours. For a fridge through a day, a ~2,000 Wh power station runs it for about 22–38 hours, and for the whole house, a wired-in battery runs the average home for about 3–10 hours per unit.

How do the types of battery backup compare?

Manufacturer spec capacities and the UPS runtimes · Our estimate other runtimes, using 85% of capacity. Fridge: 1.1–1.9 kWh a day (ENERGY STAR). CPAP: 7 W humidifier off, 8 hours a night (ResMed). Whole house: 29.6 kWh a day (EIA). How we calculate

When is a power bank or CPAP battery enough?

For phones and one small device for a night. We assume 100 Wh, the most a spare lithium-ion battery can be without airline approval (TSA). That runs a ResMed AirSense 10 for about 1 night with the humidifier off, or about 4 hours with it on at 22 W.

The catch: one night is the ceiling. It is for travel and short outages, not a fridge. See the CPAP guide for bigger options.

What does a UPS actually do?

A UPS sits between the wall and your computer or router and takes over the moment power drops, so nothing reboots. APC rates its 600 VA, 330 W Back-UPS BE600M1 at about 4.3 hours for a 10 W modem and router, 30 minutes at 80 W and 10 minutes at 180 W (APC data sheet).

Who it’s for: anyone working from home who needs to save work or keep Wi-Fi up. The catch: minutes, not days, for anything bigger than a router.

What can a portable power station run?

The fridge, a CPAP, Wi-Fi, lights and phones, plugged straight into the unit. A ~2,000 Wh station runs a typical fridge for about 22–38 hours, fridge only, so it keeps one running through an overnight outage. No install, and it runs indoors because it makes no exhaust.

Who it’s for: renters, apartments, and most homes that need the essentials for about a day. The catch: you run cords to each appliance, and at about 50 lb it mostly stays in one room.

Can a power station run circuits in my panel?

A few can. The Anker SOLIX F3800 takes up to six 3.84 kWh expansion batteries and offers 120/240 V output (Anker). Anker’s Home Power Panel connects one or two F3800s, and its backup load center feeds 12 circuits (Anker manual). Anker also sells the F3800 with a 10-circuit manual transfer switch (Anker).

On its own, the F3800 runs a typical fridge for about 41–71 hours. With one expansion battery (7,680 Wh), that becomes about 3.5–6 days, fridge only, enough to keep a fridge running through a 3-day outage.

Who it’s for: owners who want lights, the fridge and the furnace fan on house circuits without a wired-in battery. The catch: an electrician installs the panel or switch, and it runs chosen circuits, not the whole house.

When does a wired-in home battery make sense?

When you want most of the house on, with no cords and no switch to flip. The FranklinWH aPower 2 stores 15 kWh with 10 kW continuous (FranklinWH), about 10 hours of the average home’s use per unit. The Enphase IQ Battery 5P stores 5 kWh per unit (Enphase), about 3 hours, so most homes stack several. Systems like Tesla’s switch the house to battery by themselves when the grid drops (Tesla).

Who it’s for: homeowners, especially with solar. The catch: the highest cost, plus a permit and a professional install. The whole-home guide covers sizing.

What about a battery backup sump pump?

It is a second 12 V pump in the same pit, with its own battery, that turns on by itself during an outage or when the main pump fails (Basement Watchdog). It only protects the basement. The sump pump guide compares it with running your main pump from a power station.