Buyer's Handbook
A battery in a box with outlets on the front. The hard part is not choosing a brand, it is knowing which two numbers on the label decide whether the thing will do what you bought it for. This handbook covers those numbers, the safety difference that makes a battery station usable indoors, and how to size one to your own house.
Reviewed August 2026. We re-check this guide quarterly.
Start here
The lights go out around dinner. By nine you have found the flashlights and everyone has adjusted. By eleven the questions have narrowed to four: the food in the refrigerator, the phones, a lamp to read by, and whichever medical device in the house has a plug on it. None of those needs much power. What they need is steady power, indoors, for a day or two.
That is the job a portable power station does well, and it is a smaller job than most product pages imply. The specifications people compare are usually not the ones that decide the outcome. Two numbers do most of the work, and one safety fact separates this category from the generator sitting next to it on the shelf.
Before you buy
Answer these before you look at a single product. The answers narrow the field faster than any specification comparison.
What has to stay on, by name?
Write the list. A refrigerator, a phone charger, two lamps, a modem, a machine somebody sleeps with. Five or six items is typical. A list you can read out loud is worth more than any wattage guess, because it converts directly into the arithmetic further down this page.
How long do you need it to last?
A four-hour outage and a three-day outage are different purchases. Most households in most regions are buying for the first case and hoping it covers the second, which is a reasonable position as long as you know that is the trade you made.
How will it be refilled?
A battery holds one tankful. Beyond that you need a way to put energy back in: a wall outlet once the grid returns, a vehicle, or solar panels. If your answer is solar, the panel is part of the purchase rather than an accessory, and it changes the budget considerably.
Who has to move it, and how far?
Capacity is heavy. A unit in the 250 to 500 watt-hour range is a one-hand carry. Something near 2,000 watt-hours is a two-person lift or a wheeled case. Decide who in the house needs to be able to move it before the storm, not during.
What is your budget band, and what does it buy?
Roughly, small units of 250 to 500 watt-hours run about $150 to $400, mid-size units of 700 to 1,200 watt-hours run about $400 to $900, and large units of 1,500 watt-hours and up run about $900 to $2,500 before panels. Higher spending mostly buys capacity, better battery chemistry, and faster recharging. It does not buy the ability to run electric heat or a whole house, and any listing that implies otherwise is worth a second look.
How it works
Every unit in this category is the same four components bolted together. Knowing which part is doing what makes the specification list readable, because each of the four owns a different number on the label.
A pack of lithium cells. Its size is stated in watt-hours, and that single number is the honest measure of how much energy is stored. Everything about weight, price, and runtime follows from it. When two units cost the same and one holds noticeably more, the difference is usually in the cells.
The battery stores direct current. Household outlets need alternating current, and the inverter does that conversion. Its rating sets the ceiling on what you can plug in at one time, stated as continuous watts with a higher surge figure for the moment a motor starts. An inverter cannot be upgraded later, so its rating is a purchase decision rather than a setting.
A small circuit board watching voltage, current, and temperature. When the pack moves outside its safe operating range, a properly designed management system disconnects it from the external circuit so the cells are not damaged.5 It is invisible, unmarketable, and the reason certification is worth checking.
Wall input, vehicle input, and solar input, each with its own maximum. This is the part buyers think about least and regret most. A large battery with a slow charger takes most of a day to refill, which matters when the power comes back for six hours before the next line goes down.
The distinction that matters most
A battery station and a fuel generator sit side by side in the same aisle and answer the same question, and the safety gap between them is the widest in this domain. A battery station has no engine and no exhaust, so it can run in a kitchen. A generator burns fuel, and its exhaust contains carbon monoxide.
The battery station
Silent, no fumes, no fuel to store, nothing to maintain between outages. It works indoors, which means it can sit next to the refrigerator or beside a bed. Its limits are capacity and output: it holds one tankful of energy and it cannot start large motor loads. It is the right tool for lights, phones, a refrigerator, and small medical equipment.
The fuel generator
Far more output, and it runs as long as you keep feeding it. It is loud, it needs stored fuel and maintenance, and it must be operated outdoors only. The Consumer Product Safety Commission describes portable generators as one of the leading causes of carbon monoxide deaths after storms.1 For the household that needs a well pump or a furnace running, it is still the answer, on those terms.
The safety rule that does not bend
Never use a portable generator inside a home, garage, basement, crawlspace, shed, or other enclosed area, even if doors or windows are open. Generators produce lethal levels of carbon monoxide. Operate them outdoors only, at least 20 feet from homes and buildings, with the exhaust directed away from windows, doors, and vents.1
Carbon monoxide is colorless and odorless and can kill within minutes, often before anyone recognizes the symptoms.1 Opening a door does not make an enclosed space safe. The federal warning label required on generators states that using one indoors can kill you in minutes.2
CPSC recommends working carbon monoxide alarms, battery-operated or with battery backup, on every level of the home and outside sleeping areas, tested monthly.1 That advice applies whether or not you own a generator, since neighbors have them too.
Most households that can afford both end up owning both, and using them for different jobs. If you are choosing one, the honest question is whether your list from the first section is made of small indoor loads or large motor loads. Our generator safety guide covers the other side of that decision in detail.
Reading the label
Product listings in this category are dense with figures. Four of them decide whether the unit does your job. The rest are context.
Whwatt-hours, the size of the tank
How much energy the battery holds. This is the number to compare across products and the number that sets the price. Some listings lead with milliamp-hours instead, which is a larger and less useful figure. To convert, multiply amp-hours by the pack voltage. A unit advertised at 60,000 mAh at 14.4 volts holds about 864 watt-hours, and the manufacturer should state that directly.
W continuousthe width of the tap
The most the inverter can deliver at once. Add up the running wattage of everything you plan to plug in at the same time and stay under it. A refrigerator, a modem, two lamps, and a phone charger together are usually under 300 watts. A hair dryer alone is 1,500. This is where households discover that a coffee maker and a space heater are not in the same conversation as a lamp.
W surgethe first half second
Motors draw several times their running wattage at the instant they start. A refrigerator that runs at 150 watts may pull well over 500 for a moment when the compressor kicks in. The surge rating says whether the inverter tolerates that. A unit that fails here does not fail gently: it shuts off, usually at night, usually without anyone noticing until morning.
LFP or NMCcell chemistry
Lithium iron phosphate, written LFP or LiFePO4, and lithium nickel manganese cobalt, written NMC, are the two chemistries in general use. LFP packs are heavier for the same capacity and typically rated for several times more charge cycles, which suits a unit that lives in a closet for years and gets used occasionally. NMC packs are lighter and denser, which suits carrying. For household standby use, cycle life usually matters more than weight.
Pure sine waveoutput quality
Describes the shape of the alternating current the inverter produces. Pure sine wave output matches what a utility delivers and is the safe assumption for anything with a motor, a compressor, or sensitive electronics, including medical equipment. Modified sine wave costs less and is fine for simple resistive loads. For a household unit, pure sine wave is the sensible default and most current products provide it.
One number worth knowing before you travel
The Federal Aviation Administration allows rechargeable lithium batteries of 0 to 100 watt-hours in carry-on baggage, requires air carrier approval for 101 to 160 watt-hours with a limit of two spares per person, and forbids anything above 160 watt-hours on passenger aircraft.6 The smallest product in this category is more than twice that ceiling, so a power station is a household and vehicle purchase rather than a travel one. Spare batteries and power banks must be carried in the cabin rather than checked.6
Certifications decoded
Unlike hand tools, this category does have a consumer-facing standard worth looking for. UL 2743, the Standard for Portable Power Packs, was first published on October 14, 2016. It covers devices consisting of one or more batteries in an enclosure, intended for use as a portable power source when normal grid power is not available, and it addresses construction, the charging system, and electrical, mechanical, and environmental performance.3
It does not cover phone charging power banks, which fall under a separate document, UL 2056.3 That is a useful distinction when a listing uses the phrase power bank and the picture shows something the size of a toolbox. The two are evaluated against different documents.
Do not let it become house wiring
Some of these units are now sold alongside a panel or switch and marketed as home backup. UL Solutions addresses this directly: a portable power pack certified to UL 2743, sold with a panel or switch certified to UL 1741, has not been certified to the correct standard for a stationary battery energy storage system in a residential installation. The standard the model installation codes require for that use is UL 9540.4
The scope of UL 2743 also caps aggregate lithium-ion capacity at 20 kilowatt-hours.4 A portable station is built to be plugged into and carried. Permanent connection to a home's electrical system is a different product with different rules, and that work belongs to a licensed electrician regardless of what the box says.
Lithium cells fail in a specific way. In its rulemaking on lithium-ion batteries, CPSC describes thermal runaway as the primary risk, and notes it can lead to fires, explosions, gas releases, burns, overheating, and smoke inhalation, with consumers exposed during both charging and discharging.5 The same document describes the mitigation: quality cells plus monitoring and protection circuitry, including a battery management system that disconnects the pack when it operates outside its safe range.5
None of that protection is visible on a product photograph, and none of it is claimed reliably by a listing. Third-party certification is the only practical way a household shopper can tell whether it was evaluated. That is the argument for treating UL 2743 as a filter rather than a bonus feature, particularly with unfamiliar sellers.
Sizing it yourself
Almost every sizing chart online is published by a company that sells these units. The arithmetic underneath is simple enough that you do not need one. The Department of Energy states the household formula: wattage multiplied by hours used per day, divided by 1,000, gives daily kilowatt-hour consumption.7 One kilowatt-hour is 1,000 watt-hours, which is the unit on the side of the battery.
So the whole exercise is: take your list, note each item's wattage, decide how many hours each one runs in a day, multiply, and add. Then add roughly fifteen percent, because converting from battery to outlet is not perfectly efficient and no battery is used to its last drop.
| Load | Running watts | Hours per day | Watt-hours |
|---|---|---|---|
| Refrigerator, cycling | 150 while running | 8 of 24 | 1,200 |
| Two LED lamps | 18 | 5 | 90 |
| Phones and a tablet | 20 | 4 | 80 |
| Modem and router | 15 | 24 | 360 |
| Box fan, medium | 60 | 6 | 360 |
That is about 2,090 watt-hours a day, and with the efficiency margin, close to 2,400. Which tells you something useful and slightly deflating: keeping a refrigerator and a few small things running for a full day takes a large, expensive unit. Drop the refrigerator to a cooler with ice and the same list falls to about 900 watt-hours, which a mid-size station covers comfortably. The figures above are illustrative. Yours will differ, and the wattages on your own appliances are the ones that count.
Anything that makes heat is out of reach. Space heaters, hair dryers, toasters, kettles, and coffee makers draw between 1,000 and 1,500 watts, and running one for an hour empties a mid-size battery. Central air conditioning, electric ranges, electric water heaters, and well pumps are outside this category entirely. So is heating a house.
What a portable station does well is the list most households actually wrote down in section one: cold food, light, communication, and small medical equipment. Judged against that list it is an excellent purchase. Judged as a whole-house solution it will disappoint, and the disappointment usually arrives during the outage rather than at the store. If you want the wattages measured rather than estimated, our guide to measuring power use covers doing it with an inexpensive plug-in meter over an ordinary week.
Keeping it ready
This is the failure mode that catches careful households. The unit was bought, tested once, and put away, and three years later it is flat. Four habits prevent it.
Put it on the calendar
Check the charge every three months and top it up. Manufacturers give a storage range, often somewhere near half to eighty percent, and following the manual for your unit beats following a rule of thumb. Pair the check with the smoke alarm test and it stops being a separate chore.
Keep it indoors and temperate
A hot attic and an unheated garage are both hard on lithium cells. A hall closet or a basement shelf is better. Cold reduces the capacity you can draw temporarily; sustained heat shortens the life of the pack permanently.
Run it once a year, on the real list
Plug in the actual refrigerator, the actual lamp, the actual medical device. An hour of that tells you what a specification sheet cannot: whether the surge rating handles your compressor, and how the household feels about the cable runs. Do it on a calm evening rather than during an outage.
Know how it leaves the house
A damaged or swollen lithium battery does not go in the trash, in curbside recycling, or in the used-battery boxes at retail stores. CPSC directs consumers to contact a municipal household hazardous waste collection center, asking first whether it accepts defective lithium-ion batteries, and to contact the municipality for guidance if it does not.8 Stop using any unit that swells, overheats, or smells odd, and move it away from anything that can burn.
The compared field
Each comparison below reviews a real field of products, with a named pick and the reasoning behind it. This category is early in our build, so expect this list to grow as comparisons by size and chemistry are published.
Affiliate disclosure: New World Survival earns a small commission on qualifying purchases made through links in the comparisons below, at no cost to you. This helps us cover operating costs and keep building new content. Our picks are made on the merits. Commission never decides a recommendation.
After you buy
A unit still in the box does nothing. These guides in our Energy section carry the practical steps.
Living with a portable power station
Setup, first use, where to put it during an outage, and how to run a household off one without surprises. The ownership side of everything this handbook covers as a purchase.
Read the guideMeasuring power use
How to find out what your own appliances actually draw, with a plug-in meter and a week of ordinary life. Replaces every estimate on this page with your own numbers.
Read the guideBattery systems
Where a portable unit sits in the wider picture of household storage, including chemistry, capacity planning, and what changes when a system becomes permanent.
Read the guideThe extended power outage
What happens after the battery is empty. Food, heat, water, and communication over days rather than hours, which is the context this purchase belongs to.
Read the guideProducts in this guide
The full field we have published for this category. New comparisons appear here as they are built.
We re-check this guide every quarter as products and standards change. The Weekly Readiness Brief is a quiet way to hear when it updates.