How To Know Power Bank Capacity

Generally a power bank battery uses cells with the same capacity and voltage nominal connected in parallel.

How to know power bank capacity. Power bank real capacity claimed power bank capacity battery efficiency. Most people measure power bank capacity by seeing how many times it can charge a device with a known capacity battery. Go to ebay and seach for usb lcd capacity and youll find a white little gadget for a few bucks.

What the advertised capacity actually tells you. For example if your power bank has a capacity of 20000mAh multiplying this by 37 will reveal that it has total energy as measured in mWh of 74000mWh. For example if an iPhone 6 has a 1810mAh battery and a power bank charges it 3 full times and dies half way through the fourth charge then you know the capacity is at least 1810x35 6335mAh.

Lets take a 2600mAh power bank as an example. PortaPow Dual USB Power Monitor with Data Blocker. The simplest way that is easy and faily accurate is to use a capacity meter.

In the end you can roughly estimated the actual battery capacity of a power bank for charging devices at about two thirds of the capacity stated at a 37V nominal voltage. Charge the power bank normally and then use the power through the power meter until the power bank is empty. If it takes less time than that to discharge the battery down to 3 or 4 volts then you have something less.

If the battery lasts 25 to 28 hours before the voltmeter reads about 3 or 4 volts then you indeed have a 30 Amp Hour power bank. AT35 USB 30 Meter. Inside a standard 10000 mAh power bank.

With a parallel connection the voltage of the power bank battery is the same as the voltage of the cells and its capacity is the sum of the individual capacity of each of the connected cells. This powerbank has 4 37V 2500mAh batteries together that equals 10000mAh and this is correct. Some battery banks actually state two capacities at both voltages which makes your job easier.