When you’re shopping for a portable power station or solar generator, you’ll be hit with a lot of information. Whether it’s the mess of numbers or the tidal wave of bold marketing claims, it’s important to know how to understand power station specs.
We’re big fans of cutting through this jungle to help you find the right power station. But to get the most out of any information about power stations, you’ll need a little foundation on what everything means.
This short guide will help you understand the specs for power stations.
We carefully select the products and services we link to. If you buy through our links, we may earn a commission. There’s no extra cost to you and it helps us provide this information.
The 30-Second Guide to Power Station Specs
Without beating around the bush, there are a few items worth understanding that will greatly improve your understanding of power station specs.
One golden rule to keep in mind with all power station specs and general electronic details is that there will always be some power loss and system inefficiencies. Using a cushion of 10% to 20% for every figure will help you account for these losses and inefficiencies.
Power output from the AC inverter is provided in watts. Put simply, this is the most amount of power that the power station can provide through its AC outlets at one time. The higher the inverter watt rating is, the more powerful devices you can power.
- Watts: Rate of energy use or transfer
Many devices specify their power use in watts. But if they only have the volts and amps, you just multiply the two to get watts.
- Volts x amps = Watts
The next power station spec is usually the battery capacity, given in watt-hours. This is how much energy the battery can hold, and as a result, it determines how long the power station can run your devices for. Watt-hours is the result of watts multiplied by the length of runtime in hours.
- Watts x hours = Watt-hours (amount of stored energy)
Recharging the battery also comes with some specs in watts. The higher the watts, the faster the recharge rate. The battery capacity in Watt-hours divided by the recharge rate in Watts equals the approximate number of hours. This same formula applies to runtime hours.
- Watt-hours / charging Watts = Hours to recharge
- Watt-hours / powered Watts = Hours of runtime use
The other details are usually a little more self-explanatory. You’ll have a number of outlets and specific types of ports. The main things to pay attention to there are:
- Are there enough ports to power your devices?
- Do those ports offer the right power (watts) and voltage for your needs?
If you understand these power station specs details, you can confidently skip over the mountains of marketing claims and look at the spec sheets to get an accurate comparison. Don’t forget to include things like warranty coverage and company reputation as well.
Understanding Power Station Comparisons: The Details
That rapid crash course can make your head spin. It’s a lot of info. Let’s take a closer look into each area of power station details to make sure you have a full set of tools to work with.
Spending an extra few minutes on this article could very well make all the difference in the world to ensure you get the power station that meets your needs. Once done here, you can check out our power station comparison charts to find what’s right for you. Links to our top brands are at the end of this article.
AC Inverter Output
Many power stations are classified by the watts of the AC inverter. For example, our full list of portable power stations 500W all have an inverter around 500W. This determines what types of devices you can power.
Whenever you use an AC outlet, the device pulls energy out from the system. A power station uses AC inverters to supply this power to AC devices that run on a normal household outlet. That rate of energy flowing out is rated in watts.
Watts of Common Devices
You can use our solar panel calculator to help determine your device wattage needs. But here’s a rough idea of the watts of certain devices:
- Low Wattage 5W to 50W: Phone/tablet chargers, LED lights, small fans.
- Medium Wattage 50W to 500W: WiFi routers, televisions, computers, refrigerators.
- High Wattage 500W to 2,000W: Hairdryers, microwaves, toasters, induction cooktops.
- Heavy-Duty Wattage 2,000W to 4,000W: Large air conditioning units, electric clothes dryer.
Many of the lower wattage devices can also use the DC outlets, avoiding the AC inverter entirely. These include USB ports and other DC outlets like the car cigarette lighter port and other barrel plugs.
You need to figure out what devices you want to power with the AC outlets, then select a power station with the appropriate AC inverter. It’s a good idea to add 20% to the watts you plan on using as a general cushion.
For example, if you want a whole house battery backup with a fridge and some lights, you can probably use something under 2,000W, like perhaps the Jackery Explorer 1000 v2, which might be a little small for extended blackouts. But if you want to run an air conditioner too, then you might need at least one EcoFlow Delta Pro Ultra. Most A/C units will immediate cause power demand to skyrocket, which means you need a bigger inverter (and a bigger battery, covered below).
Watts Equals Volts Times Amps
Many devices provide the power they use in watts. But not all. It might only provide the volts and amps instead.
If that’s the case, it’s easy to figure out the watts based on the volts and amps. You just multiply the two. Volts x amps = Watts.
So a device that runs at 120V (standard US home wiring) and uses 10A will use 1,200W (120V x 10A = 1,200W). This also works for DC devices that might use lower volts, like a phone charge that runs at 9V and 2.2A. That pulls 19.8W (9V x 2.2A = 19.8W).
Continuous vs. Peak / Surge
AC inverters have more than one watt rating. And knowing how to read this power station spec can be very important. The primary one you’ll find plastered all over the marketing material is the continuous rating. Another one is the peak or surge rating.
As the name indicates, the inverter’s continuous rating is the power it can provide continuously. In reality, it’s actually best to stay under about 80% of this. It’s sort of like driving a car at full speed. Although it may be able to, it will likely last longer if you don’t push it to its limits.
The peak or surge rating is made to deal with certain devices that pull a lot of power to get started. On many power stations, the peak rating is about double the continuous rating.
Head over to our EcoFlow Comparison Chart to see a wide range of these specs. It’s a great way to see the full range of power station specs to understand them.
Battery Information
The other major number you’ll see in most marketing materials as a power station spec is the battery capacity in Watt-hours (Wh). This is the amount of energy stored within the power station. You also should look at the type of battery used and how many cycles it’s rated for.
How Long Will a Power Station Run For?
The Wh battery capacity is what determines how long the power station can run devices for. It might seem confusing at first, but it’s really just a matter of knowing your energy use in watts. Then you can easily get the length of time it will run for.
The battery capacity in Watt-hours can easily be divided by your power rate in Watts to get the number of hours. Watt-hours / Watts = Hours of runtime from the power station.
Once again, it’s wise to include a cushion of about 20% here. Every battery’s actual available power is less than its lab rating. And there is some power loss when sending power from the battery to a device through things like the wires and connectors.
So if you want to run a fridge that consumes 200W on average, plus a phone charger that consumes 10W, and four LED lights that consume 40W total, you have a total power consumption rate of about 250W. Let’s add a 20% cushion to get 300W.
If you connect all of these devices to a battery that’s 1,000Wh, it will last just over 3 hours. 1,000Wh / 300W = 3.3 hours. This is a critical part of understanding how to read power station specs.
The EcoFlow Delta Pro 3 offers a large built-in battery, plus external battery packs to increase the capacity.
Battery Chemistry: LiFePO4 vs. NMC
Most portable power stations use lithium batteries to get full use of the capacity, a lighter weight, and amazing longevity. But there are multiple types of lithium ion batteries.
LiFePO4 is the battery type that has the best longevity. It can usually last for at least 3,000 cycles while keeping 80% of its charge. This means that it will be able to be fully charged and discharged (one cycle) daily for about 8 years, while still keeping a reasonable amount of its capacity.
NMC is another common lithium battery type. It has some advantages, but it’s downside is a shorter longevity. And for power station specs, this can be something to avoid. They usually are closer to 500 cycles before going to less than 80% capacity.
Once you get to this 80% capacity, the power station will still function. It’s not a magical number that causes it to fail. It’s just a common metric to standardize the expectations. You can just expect the battery to hold less energy, and therefore, it won’t power your devices for as long.
Since the battery chemistry is a main driver of longevity, you’ll notice that most warranty periods are correlated to the battery type. LiFePO4 will have the longest warranties of around 5 years while power stations with NMC batteries may only have 2 year warranty coverage.
This power station spec is hard to read and find. It’s almost always listed in the user manual if you can’t find it in the listing materials. We also always include it in our comparison charts.
Charging Details
After the inverter and battery details, companies usually start to throw out all sorts of numbers for how quickly you can recharge the power station. Some use times to 80% capacity, others tell you how quick solar can recharge it without mentioning how many panels they use. To put it mildly, these can be overly optimistic and a bit misleading.
It’s not that hard to figure out. Like the AC inverter, the charging inputs have ratings provided in watts. The higher the watts, the more power can rush in at one time. You just take the Watt-hour of the battery and divide it by the watts of the charging rate to see how many hours it will take.
And as usual, expect about 20% more time. This is mostly because there is a battery management system (BMS) inside of the power station that will intentionally slow down charging when it’s at 80% to prevent harm. It might take even longer due to these protection measures.
So if the battery size is 1,000Wh and the recharge rate is 1,000W, it will take about 1.2 hours to charge. 1,000Wh / 1,000W = 1 hour + 20% = 1.2 hours.
This is usually split into two charging inputs: AC outlet input and DC solar input power.
AC Outlet Charging
The AC charging rate is for standard US household outlets, typically running at 110V – 120V. This is often a very fast charging rate since these outlets offer a lot of power. But not always. Some small power stations have incredibly slow charging, even on powerful outlets.
The one catch is that this will also be limited by your outlet. Many are only rated for 15A. At 120V and 15A, that’s equal to 1,800W. That will be the maximum charging you can expect from that outlet, unless you use a high-amp or high-voltage outlet.
So your AC charging rate is usually the battery capacity in Watt-hours divided by the AC input watts. But don’t use more than 1,800W as the input wattage unless you know the power source offers higher wattage. That provides an idea of how this power station spec translates to charging time.
DC Solar Input
The other type of recharging rate is for DC power sources, which includes solar panels, car outlets, and other off-grid power generation. These may share one input connector, but many power stations have multiple DC inputs. This is a crucial part of reading power station specs if you want to max out off-grid charging from solar or other sources.
You’ll need to read the power station’s input specs and match it to the power available from the source you have. This gets you the estimated recharging time based on these specs. And it’s still the same calculation as the AC charging (watts are the same across AC and DC): the battery’s Watt-hours divided by the source Watts equals the number of charging hours (plus 20%).
The power station’s input specs are the most it will accept. This is mostly shown in watts, but it’s actually MUCH more important to look at the volts and amps (volts x amps = watts) for DC sources like solar. You can never exceed the volts. For more details on these specs, head over to our calculator for how many panels you can connect.
For example, if the power station marketing claims it can use solar to recharge in 2 hours, that depends on how many watts of solar is connected. If that’s based on 200W of solar but you only have 100W, it will take double the time.
Also, if the power station says it can accept 1,000W but has a maximum voltage of 50V, you can’t go over that 50V. Even if you only have 800W of panels connected, if you go over that 50V, you can cause serious damage. The way you connect solar panels has a lot to say here because series connections add up voltage across solar panels.
Car charging can vary wildly. If you use something like a Universal DC Car Charger for Power Stations, you can get a lot of power out of a car. But if you only use the cigarette lighter port, it will be limited to about 120W (12V at 10A) because those outlets are not made for large power draws. You may need to consider the adapter you use too, such as the XT60 vs XT60i for EcoFlow.
Other Details: Weight, Ports, Warranty
The rest of what you need to know to pick the right power station is straightforward. But don’t overlook the crucial details.
The bigger power stations made to power an RV or home can be quite heavy. If you can’t lift it, you’re not going to enjoy it as a portable power source. For example, the Bluetti AC50B is a small power station that nearly anyone can handle and bring around. But the EcoFlow Delta Pro and Bluetti EP500 are both much larger units that can be tough for some people to deal with.
Another thing to remember is that sometimes you can use multiple inverter units and/or extra batteries together. This can be a great way to scale up a modular system, increasing both battery size and inverter capacity.
The available outlets and ports can also be incredibly different from one power station to another. You can look for:
- 30A or 50A AC outlets: Useful for powering a home subpanel, heavy-duty appliance, or an RV.
- High-amp DC ports: Best for using to power a distribution panel or DC fuse box.
- Sufficient USB-A and USB-C ports
Finally, many power stations are an investment you should expect to last many years. Protect yours by making sure to buy from a reputable company that offers a solid warranty. We strongly recommend sticking to the big name brands that are trusted, even for the small power stations. Solar Waypoint puts in tons of effort to ensure you get the right product from a top brand.
The reality is that even with well-designed and tested systems, there is always going to be expected failure rates. That’s what happens when you produce tens of thousands of units at scale. By going with a reputable company, you can have confidence that they’ll have your back if things go south. Check out our Product Guide page to get an idea of the companies we recommend.
Test Your Knowledge: Review Specs
Are you ready to put your new skills to the test? In this section, you can choose up to three power stations and a group of specs to compare. We also have links to specific brand comparisons in the section below this to see more details on their power station specs.
Select Power Stations
Select up to three power stations to compare:
Wrap Up: Understanding Power Station Specs
Before pulling out that credit card, make sure the power station features and abilities meet your needs. It might seem overwhelming, but carefully look at the AC inverter ratings, battery capacity, and charging rates to make sure you understand the power station specs before clicking buy.
Ready to see some of the best power stations in a fierce battle of the titans? Check out our review of EcoFlow vs. Bluetti. These two brands duke it out in an attempt to reach the top of the industry.
Or check out some of our power station spec comparison charts:
