Best Portable Power Station for a Power Outage

For a short outage, a small station covers a router, lights, phones and a CPAP; for three days with a refrigerator in the plan, you need thousands of watt-hours. Count the loads you would keep running, multiply by hours, and compare the total with a unit's watt-hours. This guide does that for a 72-hour example.

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Outage priority list

An outage is a list of choices about what to keep running. A sensible order, from least to most energy:

1. Communication. Phones and a Wi-Fi router are small loads. On our assumed watts, a router at 10W draws about 240Wh a day.
2. Light. Four LED bulbs at an assumed 40W for five hours is 200Wh.
3. Medical devices. Ready.gov says to talk to your medical provider about an outage plan for any electrically powered medical device. A CPAP is one example; see the note below.
4. Cold food. Ready.gov and the FDA's food-safety pages say a closed refrigerator keeps food cold for about four hours, and a full freezer for about 48 hours (24 hours if half full). Food above 40 F for more than four hours is discarded under that guidance, and one FDA page says two hours.
5. Heat, with caution. A furnace blower or a sump pump draws far more than a router, and motors start with a surge above their running watts. Check surge against a unit's rating before you plan on them.

Medical devices and your provider

If a household member relies on an electrically powered medical device, plan that part with the medical provider who prescribed it. A power station can supply watts, and a provider tells you how many hours you need and what happens if you run short. Read the device's rated watts on its label or manual; features such as a humidifier or heated hose raise the draw. The CPAP sizing guide walks through the arithmetic for one common device. My Patriot Supply's page says the Grid Doctor 300 runs a CPAP for up to about 8 hours, which is the seller's statement for its own test conditions.

Gas generators and carbon monoxide

If your outage plan includes a gas generator, Ready.gov and the Consumer Product Safety Commission say to run it outdoors only, at least 20 feet from windows, doors and attached garages, never inside a house, garage, basement or shed, even with doors open. Keep carbon monoxide alarms with battery backup on each level. A power station burns nothing, so the seller says it is safe to use indoors; keep it ventilated while it charges and use the approved cables. And do not plug a power station into a wall outlet to power the house; plug devices into the station itself.

A 72-hour energy budget

Here is one example household, with every watt figure an assumption you replace with the numbers on your own labels. None of these loads are sourced facts. The refrigerator row assumes the compressor runs about eight hours of the day, a duty cycle that varies by model and kitchen temperature.

Without the refrigerator the total is 850Wh a day, or 2,550Wh over 72 hours.

Check the budget against each unit

The usable energy of a unit is its watt-hours times 0.85, our planning assumption for conversion losses.

• Grid Doctor 3300 (2,048Wh by the seller): 2,048 x 0.85 = 1,741Wh usable. Without the refrigerator, that covers the 850Wh daily budget for about two days (1,741 divided by 850 is 2.05). With the refrigerator in, the 72-hour total of 6,150Wh divided by 1,741 is 3.5, so you would need four 2,048Wh batteries, which means the base unit plus three expansions. That is within both of the seller's printed limits ("up to 7 expansion batteries" in the specifications and "up to four" in the FAQ, a conflict the 3300 review prints), though prices for expansion batteries are not in this guide's data.
• Grid Doctor 300 (320Wh by the seller): 320 x 0.85 = 272Wh usable. The router, lights and phones alone use 530Wh a day, so the unit covers about half a day of just those (272 divided by 530 is 0.51 days). The seller's page says it is not designed for full-size refrigerators, microwaves, HVAC, sump pumps or space heaters, so the refrigerator row is outside its range. Details are in the Grid Doctor 300 review.

Solar recharging helps at the margin: an example 200W panel in four hours of good sun gives about 800Wh before losses, which with our 0.85 is about 680Wh a day. Sun hours vary by season and weather, so this is an estimate, and a cloudy stretch can bring it close to nothing. The 3300 ships with one 200W panel and the 300 with one 100W panel at the prices below.

Which Grid Doctor fits which list

The 3300's own page says it is not ideal where you need 240V output for large HVAC systems or full-home load panels. "Home backup" in this guide means essential loads on cords, not the entire house. Nothing here is wiring advice.

Some readers pair them: the 300 for the bedside and travel, the 3300 for the kitchen. For where the two compare, see the 3300 vs 300 guide; for the overall picture return to the best portable power station for home backup.

Before the storm: a short checklist

• Charge the unit fully. Check it again if it has sat for months; the seller's page says to recharge about every three months.
• Lay out panels and cords where you will use them, and test them in daylight.
• Write down your loads' watts from their labels.
• Fill a cooler or move food using the Ready.gov and FDA guidance: keep the refrigerator closed, and use an appliance thermometer.
• Keep a battery-backed carbon monoxide alarm working on every level.
• Ask your medical provider for an outage plan if a device matters.

What about the EMP feature?

My Patriot Supply says the 3300 has built-in EMP Intercept Technology designed to help protect internal components from lightning, grid surges and electromagnetic pulse. This site found no independent test of that claim, and it does not factor into the budget above. The EMP claims guide explains what it does and does not establish. How long a battery lasts through years is a separate question, answered in how long portable power stations last.

FAQ

What size power station do I need for a three-day outage?

Add each load's watts times its daily hours, multiply by three, and compare with a unit's watt-hours times 0.85. In our example household the answer is 6,150Wh with a refrigerator and 2,550Wh without.

Can a power station run a refrigerator all day?

On our assumptions, a 2,048Wh unit runs a 150W-while-running refrigerator for about 11.6 hours of continuous running. The seller's FAQ says "up to 30+ hours depending on the model", which differs because of duty cycle and model size.

Is a power station safe to use indoors?

My Patriot Supply says it is, because there is no combustion. Keep it ventilated while charging, use approved cables and read the manual.

Should I rely on it for a medical device?

Make that plan with your medical provider, as Ready.gov advises, and check your device's rated watts before you size anything.

Sources

• Ready.gov, Power Outages, read 2026-11-04
• CPSC, Generators and Engine-Driven Tools, read 2026-11-04
• FoodSafety.gov, Food Safety During a Power Outage, read 2026-11-04
• My Patriot Supply, Grid Doctor 3300 product page, read 2026-11-04: https://www.mypatriotsupply.com/products/grid-doctor-3300-emp-solar-generator
• My Patriot Supply, Grid Doctor 300 product page, read 2026-11-04: https://www.mypatriotsupply.com/products/solar-generator-300w-by-grid-doctor

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