A Guide to Understanding Battery Capacity

A portable power station is the perfect power backup solution whether you’re camping, living off the grid, or just preparing for an emergency. It’s crucial to be educated on battery capacity if you’re planning on getting a portable power station, so here is a guide to battery capacity to help you figure out which size is most suitable for your backup power needs.


What is battery capacity?

Capacity indicates how much energy a power station can hold, typically indicated in watt-hours (Wh), which indicate energy capacity. Energy capacity in Wh shows how much energy a battery can store or provide in a single hour.


How do I calculate the capacity of a battery if it’s not listed in Wh?

You may notice that the battery you purchase has its capacity listed in mAh, Ah, Wh, or kWh depending on the type and size of the battery. To convert amp-hours to watt-hours, we can use the following equation:

Energy capacity (Wh) = Voltage (V) × Amp-hours (Ah)

Pretend you own a 200Ah 12V battery and would like to know its capacity in Wh. You can use the above equation to calculate the following:

200Ah × 12V = 2400Wh


How much battery capacity do I need?

It depends on how much energy each of your appliances uses. That means you need to find out how many watts your devices need to run. This number is usually listed somewhere on the device itself or its outer packaging.

Multiplying the wattage of your device by the number of hours you want to use it for will give you the total watt-hours required to power each device. Then, add all your watt-hours for each device together to get the total amount of watt-hours you need the power station to provide. For example, let’s say you need 400 watt-hours to power your lights, 300 to charge your phone, and 300 to charge your laptop. Your total watt-hour requirement would be 1000Wh (400 + 300 + 300).

With this number, you can select a battery that meets your total energy demand, in this case up to 1000Wh.


Purchasing a portable power station with a battery capacity that meets your needs will ensure that you have an optimal source of power without paying more for it than you have to. Vanpowers’ line of portable power stations, including the Vanpowers Super Power Pro 2000, can accommodate a variety of power consumption levels while staying within your budget, ranging from 640Wh of capacity to as high as 2096Wh. Meanwhile, the Vanpowers Solar Generator set comes with a Vanpowers 200W Solar Panel that can draw energy from the sun to power your devices for even longer periods of time. If you're looking for a portable power station that can handle your specific power needs, be sure to check the battery capacity before buying.