Other factors that weighed into our decisions included the number and power output of each power station’s inputs and its charging options. Capacity A portable power station’s capacity, listed in watt-hours (Wh), determines how much energy a power station can deliver over time. Often, what makes a power station great is the kind of software it includes and what features it offers to help you best manage your power station. Noise Portable power stations heat up when operating for extended periods or when they’re providing power for multiple devices. However, other portable power stations do not have a weather rating, so it’s important to check if you plan on using your power station outdoors.