What Size Portable Power Station Do You Need?

A portable power station is essentially a big battery that stores energy rather than generating it, and its size is measured in two ways: how much energy it holds, in watt-hours (Wh), and how much power it can deliver at once, in watts (W). Get either number wrong and the station will either not run your appliance at all, or run it for far less time than you expected. The good news is that sizing is arithmetic, not guesswork, and this page walks through it with real UK prices and runtimes.

The short answer for most households: a station in the 300 to 700Wh class covers phones, tablets, laptops, cameras and LED lights on day trips or short overnights¹. A 2kWh-class station, delivering around 2,000W of continuous output, is the point at which a fridge, a TV and a router can run together through a short power cut². For keeping a normal level of living during an outage, including a TV, microwave and hot shower, maker guidance puts the basic minimum at 10 to 13.5 kWh, which is firmly home-battery territory rather than portable power station territory⁴.

What a portable power station is, and what it can power

A portable power station is an energy storage unit with multiple port options, including AC outlets, USB ports and DC outlets, that stores energy but does not generate it⁶. It is essentially a portable battery pack equipped with various outlets and charging options, recharged from the grid at a wall plug, from a car's alternator, or from solar panels⁶. Inside are three main components: a battery, an inverter and a charge controller⁸. The inverter converts the DC power stored in the battery into the AC power your household appliances need⁷.

Physically, these units are light and about the size of a small drink cooler, and many come with ergonomic handles or wheels⁶. That portability is what separates them from a fixed home battery, and it is why makers describe them as ideal for recreational activities as well as home backup solutions⁶.

What they can power is broad: makers state that portable power stations can charge a wide range of devices, from smartphones and laptops to electric coolers and medical equipment⁷. Typical uses include charging devices, running lights and powering small appliances off the grid, providing a reliable power source for a laptop and other devices when working remotely, and serving as emergency backup power sources during blackouts⁷. For context on the smaller end of portable power, consumer guidance notes that portable power banks can hold enough power to charge up a mobile several times, and are well worth having to hand⁹. A power station is the step up from that: enough stored energy to run mains appliances, not just top up a phone.

For a household thinking about energy independence, a power station is a genuine off-grid asset, but its independence is bounded. It stores energy rather than making it, so unless it is paired with solar panels it depends on the grid to refill. Attach panels and it becomes what makers call a solar generator, no longer needing an outlet to recharge⁶.

How to choose the right size for what you power

The battery's capacity determines how much power the unit can store and deliver, and higher capacity models offer more runtime⁷. Sizing therefore starts with the devices you plan to power, not with the station⁷.

The method is simple. First, list the appliances and their wattages. Second, add up the watts of everything that will run at the same time: that total must be below the station's continuous output rating or the inverter will shut down. Third, work out the energy each appliance uses over the period you need it, in watt-hours, by multiplying its watts by the hours of use. Fourth, add a margin for conversion losses, because not all the stored energy reaches your device.

A worked example from maker guidance shows the last step clearly. For a daily use of 920Wh, the required capacity is calculated as 920Wh divided by 0.85, giving roughly 1,080Wh¹. In other words, the nameplate capacity has to be larger than the daily use to allow for inverter and conversion losses. That single adjustment is the difference between a station that lasts the evening and one that cuts out an hour early.

Two further points shape the answer. If the aim is to run a refrigerator, the station should have at least 1,000Wh capacity and a high pure sine wave AC output⁵. And if several essentials need to run together, the continuous output rating matters as much as the watt-hours: one example combination of a 1,500W kettle, a 200W fridge and 100W of electronics puts the practical minimum at 1,800W continuous output¹.

Compact models: 300 to 700Wh for outings and one night away

The smallest practical class of power station holds 300 to 700Wh, and maker guidance is clear about what this range suits: phones, tablets, cameras, laptops, LED lights and other low-power gear on day trips or short overnights¹. This is the class to think of for a phone that needs several charges, a laptop for a working day, and a set of lights for the evening.

The next band up, 800 to 1,200Wh, is described as a useful weekend-camping range for a compressor fridge, electronics, lighting and occasional higher-wattage use¹. The compressor fridge is the significant item here: it is the first appliance that runs for hours rather than minutes, and it is the reason the capacity needs to double.

For UK buyers, this class is well served and inexpensive. BLUETTI's small stations include the AC2A at £189, the Elite 30 V2 at £199, the EB3A at £219, the AC2P at £249 and the AC50B at £349, with the AC70 at £419¹⁰. The EB3A is rated at 600W output with 268Wh of capacity, which tells you exactly what this class is for: a 600W ceiling rules out kettles and microwaves, and 268Wh will run a laptop for a working day but not a fridge overnight¹³.

For a household's backup planning, a small station is honest about its limits. It will keep phones, a router and a light going through an evening power cut, which covers communication and visibility, the two things that matter most in the first hours of an outage. It will not run heating, refrigeration or cooking, and pretending otherwise is how people end up with a flat station and a warm freezer at midnight.

What a 2kWh-class unit will run and its runtime

The 2kWh class is where a power station starts to behave like a household backup rather than a gadget charger. A 2,000W station usually delivers around 2,000 watts of continuous output, with many models at 2,200W or 2,400W and others about 1,800W, and such a unit often has a battery around 2,000Wh as well². Anker's 2000W range pairs a capacity of around 2 kWh with up to 2,400W of output³.

The runtimes, from maker figures for a 2kWh model, are worth reading carefully because they show how quickly capacity drains as load rises:

³

The pattern is the inverse of what most people expect: halving the load roughly doubles the runtime, so a 100W device runs for around 16 to 18 hours while a 1,000W device runs for only 1.5 to 2 hours³. The maker notes these figures come after normal power conversion losses, the same margin the sizing method above builds in³.

Real products in this class include the BLUETTI AC180 at 1,800W with 1,152Wh, the AC180P at £799, the Elite 200 V2 at 2,073.6Wh with 2,600W output, and the AC240P at 2,400W with 1,843Wh¹³. Note that capacity and output are independent choices: the AC180P has more watt-hours than the AC240P but less output power, so a buyer has to check both numbers against their own load list.

For a power cut, this class runs a fridge, a router, a TV and lighting together for an evening, and a fridge alone for most of a day. What it cannot do is run electric heating for any useful length of time: a 1,000W load flattens it in under two hours³.

Above 2kWh: backup for full days and longer stretches

Above the 2kWh class, portable stations blur into expandable home backup systems. Maker guidance splits household backup needs into two levels: 2 to 5 kWh should suffice for maintaining basic survival needs such as a fridge, Wi-Fi and LED lights, while 10 to 13.5 kWh is the basic minimum for maintaining a normal level of living during an outage, including a TV, microwave and hot shower⁴. The same guidance sizes small homes of 1 to 2 bedrooms at 4 to 5 kWh recommended, and medium-sized families in 3 to 4 bedrooms at 5 to 8 kWh⁴.

The portable-station market has followed this ladder upward through expansion batteries rather than ever-bigger single boxes. EcoFlow's DELTA 2 expands to up to 3kWh, the DELTA 3 to up to 5kWh, the DELTA 3 Plus to around 5 kWh with extra batteries, the DELTA 2 Max to up to 6kWh, and the DELTA Pro 3 to up to 12kWh, or more with chaining¹⁵. At that top end the unit is a whole-home backup battery that happens to be movable, and the maker positions the DELTA 2 Max explicitly for use as home backup during blackouts¹⁶.

For comparison, a small cabin or tiny home with daily consumption up to 3kW is advised to buy a battery of 3 to 5kW to power critical loads during an outage¹⁸, and a compact apartment focused on essentials during short outages usually needs 1 to 2 batteries, roughly 5 to 15 kWh total¹⁹. A typical UK domestic battery storage system is 4kWh to 10kWh²⁰.

The independence picture changes at this scale. A 5 kWh station paired with solar panels can ride through a day-long cut without the grid, and a 12kWh system approaches genuine household sovereignty for essential loads. The dependence that remains is on the maker's expansion batteries, which are proprietary, and on having bought enough capacity before the outage, because no station grows mid-power-cut.

Four checks before you buy: capacity, inverter and ports

Four checks cover almost every sizing mistake. They come from maker buying guidance, and each catches a different failure.

1. Battery capacity in watt-hours. Determine the battery capacity you need based on the devices you plan to power⁷. This sets runtime, using the method and the 0.85 conversion factor above¹.
2. Inverter quality and capacity. Check the inverter's quality and capacity to handle the devices you want to power⁷. The inverter converts DC stored power into AC⁷, and its continuous rating must exceed your simultaneous load, with the 1,800W example showing how a kettle, fridge and electronics add up¹.
3. Output ports. Ensure the power station has the right types and number of output ports for your devices⁷. Stations feature AC outlets, USB ports for charging smartphones and tablets, and DC outlets⁷.
4. Size and weight. Evaluate the unit's size and weight to ensure it is suitable for your intended use and easy to transport⁷.

The most common mistake is buying on watt-hours alone. A 2,000Wh station with a 600W inverter cannot run a kettle no matter how much energy it stores, and a 2,400W station with 500Wh will run the kettle for minutes, not hours. Capacity and output are separate specifications, and both must clear your list.

A second, quieter mistake is ignoring surge. Appliances with motors and compressors draw more than their rated power when starting, and the inverter has to absorb that. The pure sine wave requirement for refrigerators exists for the same reason: the compressor needs clean AC to start reliably⁵.

Ways to recharge: mains, vehicle socket or solar

The lithium-ion batteries in portable power stations can be recharged in several ways: from a wall plug, from a car's alternator while driving, or from solar panels⁶. Every station in the UK market supports the first two; solar support is near-universal but the details vary enough to check.

Small USB-first stations are the most constrained. The Anker SOLIX C300 DC recharges with any USB-C PD charger with 30W or higher output, needs an 18W or higher USB-C wall charger for first activation, and supports up to 100W solar recharging, with the maker recommending its own 100W or 60W panels²¹. Its sibling, the C300X, takes the same 30W USB-C PD chargers and, for solar, panels with an output between 11 and 28V²². Compatibility is not universal even within one maker's range: the C300X is not compatible with the Anker SOLIX PS30 or other 5V to 3A USB-C solar panels²².

Larger stations take conventional panels. The EcoFlow DELTA 2 accepts solar panels at 110W, 160W, 220W or 400W without losing charge speed¹⁶. Because PPS units have solar charging capability, you do not need to plug the station into an outlet to recharge it⁸, which is what turns a stored-energy box into a self-refilling one.

For sizing solar input, the arithmetic runs the other way: a 100W panel in typical UK conditions delivers on the order of 100Wh per hour of good sun, so refilling 2,000Wh from a single 100W panel is a multi-day project. Panels themselves are not trivial objects: plug-in solar panels are often around 1m x 2m and weigh more than 20kg²³. The practical reading is that solar extends autonomy, as maker guidance puts it for caravan use, rather than providing instant refills¹.

Safe to use indoors: fume-free, quiet and no airflow needed

This is the property that most clearly separates a power station from a fuel generator, and it matters for how a household can actually use backup power. A portable power station is safe to use indoors or outdoors, with no emissions of any kind, including carbon monoxide gas⁶. There is nothing to ventilate, no fuel to store, and no exhaust to route away from windows.

The contrast with generators is stark. A petrol generator must sit outside, away from doors and windows, with cables run in; a power station sits in the hallway next to the fridge it is running. Installing a small scale generator is notifiable work under building regulations guidance, listed as notifiable both outside and within a bath, shower room, kitchen or special location²⁴. A plug-in power station involves none of that: it is an appliance, not an installation.

Noise follows the same pattern. Portable power stations are extremely quiet, even more so than inverter generators⁶. The EcoFlow DELTA 2 Max is rated for quiet operation at 30 dB, which the maker compares with 55 dB or higher for other units, and describes as ideal for indoor use¹⁶. Thirty decibels is a whisper-quiet library: a station in the room will not interrupt conversation, television or sleep.

For energy independence, this indoor-safety is what makes a power station a realistic everyday tool rather than an emergency-only one. It can be used nightly for a home office, weekly for camping, and then pressed into service in a power cut, all in the same room as the people using it. The dependence that remains is on the grid or sun for recharging, and on the maker's charger and cables, but there is no fuel supply chain, no ventilation requirement and no carbon monoxide risk at all.

From cool-box scale to wheeled trolleys: bulk and carrying

Portability is relative, and the market spans a wide range. At the small end, an Anker portable power station weighs 3.7kg and can be charged with a solar charger²⁵. A 1000W power station often weighs 10 to 14 kg¹⁷. The EcoFlow DELTA 3 is housed in an IP65-rated chassis of no more than 12.5 kg¹⁵. Above that, stations grow to the small-drink-cooler scale, often with handles or wheels⁶, and the largest expandable systems are effectively wheeled appliances that live in one place.

The weight ladder tracks capacity closely enough to plan around:

The practical question for a household is where the station will live and how often it will move. A unit that lives under the stairs and comes out twice a year can be heavy; a unit that goes camping monthly or moves between rooms during a cut needs to be liftable by the person who will lift it. Maker guidance is blunt on this point: evaluate the unit's size and weight to ensure it is suitable for your intended use and easy to transport⁷.

UK prices for portable power stations

UK list prices, from maker price lists and product pages, span a wide range. At the small end, BLUETTI's smaller collection runs from the AC2A at £189 and the Elite 30 V2 at £199 to the AC50B at £349 and the AC70 at £419¹⁰. The mid-range includes the Elite 100 V2 at £469 and the AC180P at £799¹⁰. The larger class starts at the AC240 at £1,699 and the AC180P list price of £1,399, up to the AC240P at £1,899 and the Elite 400 at £1,799¹⁰.

For context, portable generators start at around £160 but can go up to £2,000 or more²⁵, and makers note that power stations are on the pricey side, often costing as much as an inverter generator⁶. Hiring is an alternative for one-off needs: a 1.6kVA portable generator costs around £76 for a day, or £110 for a week²⁵. At the whole-house scale, a typical 5kWh domestic battery system costs around £4,600, with battery storage costs up to £10,000 depending on size, and a typical UK domestic system of 4kWh to 10kWh costs between £2,500 and £10,000 fully installed²⁶.

Prices move frequently and list prices are not street prices, so treat these figures as markers from maker price lists rather than quotes. What the ladder shows is that capacity is the main driver of cost, and that the jump from a device-charging station to a fridge-running station is roughly the jump from £200 to £800, while the jump to a 2kWh-class unit is another doubling beyond that.

Battery type and cycle count: the keys to a long life

A power station's lifespan is set by its battery chemistry and how it is used. Independent guidance is clear that a battery's lifespan depends on its type and how often it is charged and discharged fully, and that the lifespan of a battery will depend on the model, so buyers should look for this information before making a decision²⁰.

The current standard chemistry is lithium iron phosphate, LiFePO4, and the cycle-life figures are strong. Many current LiFePO4 stations are rated for roughly 3,000 to 6,000 cycles before falling to about 80% of original capacity¹. BLUETTI states its LiFePO4 batteries last 2,500 to 6,000 or more cycles, roughly 7 to 17 years of daily use¹³. Independent guidance puts lithium-ion batteries at around 4,000 charging cycles, typically lasting 10 years or more²⁰, and maker guidance for lithium-ion, especially LiFePO4, home batteries gives a lifespan often of 10 to 15 years, or 5,000 to 10,000 cycles¹⁹. At the system level, official guidance gives domestic battery storage a lifetime of around 10 to 15 years²⁶.

Newer stations' lithium batteries are lightweight, more efficient, and safe to discharge to a lower voltage without damaging the battery⁸, which is why usable capacity is now close to nameplate capacity. One maintenance note from maker guidance: LiFePO4 batteries in newer models prefer not being kept at full charge all of the time², so a station left plugged in at 100% for years is not being stored the way its battery would prefer.

For a household, cycle life is the number that determines cost per year of ownership. A station rated at 3,000 cycles used once a week lasts decades; the same station cycled daily reaches the end of its rated cycles far sooner. The dependence worth noting is on the maker's warranty terms, which differ by model, and on the battery being non-replaceable in most units: when the battery reaches end of life, the station is done. Check the cycle rating and the warranty years for the specific model before buying, because they vary more between models than any other specification on the box.