How to Choose a Portable Power Station
Before deciding on a portable power station, there are a few key factors to consider.
Consider The Battery Capacity
One of the first steps for choosing the right power station is determining how much battery storage you need. This is most often referred to as the battery capacity in watt-hours. Theoretically, this means a 500Wh power station can output 500 watts for one hour. As we'll discuss, the nuances of power stations mean we don't quite get the full advertised capacity.
We recommend jotting down each device you plan to use and determining how many watt-hours it will consume. Suppose you need to charge your laptop, and it consumes 50 watts. A 500Wh battery would recharge your laptop ten times. In a perfect world, the advertised capacity would be one hundred percent accurate, but we do not actually get to use the full amount of watt-hours advertised. This is because power stations need to have enough available capacity to continue to power aspects such as the AC inverter, the digital screen, and the fan operation, to name a few. When discharged all the way to zero, this ensures the power station will still have enough battery to recharge without killing the battery. As a buffer, we recommend at least a 20% margin in battery capacity. That means a 500Wh power station will have closer to 400Wh available.
How Many Watts Do You Need?
Some power stations are meant for charging small accessories and electronics, while others can be full-home backup solutions. Finding the right size power station is largely determined by the amount of wattage you'll require. The inverter on your power station converts direct current (DC) to alternating current (AC) and is rated by constant capacity and surge capacity. Appliances with high initial electrical current, such as a table saw, will have a large surge wattage when first starting. Think of it like riding a bike. When you first get going, the effort required to start pedaling takes much more than when at cruising speed.
Smaller units in the 100-500 watt range are ideal for charging phones and laptops or running a few lights. Medium-sized units with inverters rated up to 1500 watts provide enough power to run appliances like coffee makers and refrigerators while often still being portable enough for a weekend camping trip or tailgate. Larger-sized power stations have inverters up to 3000 watts or more and are generally reserved for high-power uses such as AC units and high surge power tools. These units will also have enough battery capacity for extended use, say during a power outage or for off-grid living. Ideally, you should consider your wattage needs by determining what appliances and devices you need to be powered and for how long. Also, consider the total wattage you will need with multiple devices plugged in at the same time. This will give you a good starting point for narrowing down appropriate-sized options.
What about Charging?
Charging speeds between different models and manufacturers can vary significantly due to the battery chemistry and the difference in wattage for each brand's wall charging unit. Some units are capable of fully recharging through AC in under an hour, while others can take over fourteen hours to reach a full charge. Folks with specific charging needs, such as those using their power stations for construction work, will benefit from a quicker recharge between jobs. If fast charging speed is important for you, consider options with a higher AC input. Also, if you plan on utilizing solar recharging, consider options that provide plenty of solar input. Most power stations are also equipped with custom charge settings between eco/slow and the ability to charge to a certain percentage. Some models also have ultra-fast charge settings, which come in handy for last-minute recharges, although this will cause more wear on your battery if used consistently. Ultimately, consider the type of applications you need your power station for and if a faster recharge is worth prioritizing.
Battery Chemistry
Almost all portable power stations utilize lithium-ion batteries, but a couple of different chemistries are used between brands and models. Many companies are shifting their designs towards lithium iron phosphate (LiFePO4) battery chemistry because it's safer, has a longer lifespan, and has less thermal runaway. You may also commonly see nickel manganese cobalt (NMC) used in power stations. NMC does have a higher energy density, which allows for smaller, more compact designs. Typically, we recommend steering towards LiFePO4 because of its longer lifespan and more stable chemistry, but NMC batteries from a reputable brand are plenty safe. While battery chemistry is an important consideration, if a specific power station checks off all the right boxes but you're unsure of the battery chemistry, consider whether the longer lifespan is necessary or not. NMC batteries with shorter cycles will still last plenty long for off-grid camping, during emergencies, or for occasional power tool use. Unless you need to cycle your power station continually, such as those relying on their power station for full-time RV/van use, NMC batteries can still be a viable option.
