Today we have a massive amount of information and functionality right in our pockets at all times. Something we couldn’t even imagine about a decade ago. We communicate, read, find news and weather forecasts, navigate, and so on and so forth through a tiny device fitting cozily in our hand: our smartphone.

Everything comes at a cost, and all the functionality needs power, a lot of energy. This brought about the daily essentials of most of us today: the power banks. 

There are hundreds of power banks available on every website, in every store. Moreover, power banks come in every imaginable form, size, color, and capacity. So, how do you know what kind of power bank you need?

What is a Power Bank

The term is defined as “A portable battery-powered device for charging the battery of a mobile phone or other electronic devices.” 

A power bank is a portable electronic gadget that stores a certain amount of energy and can transfer it to your smartphone or any other device. You charge your power bank at home and carry it around if you need some power when out and about. 

power bank


Capacity is one of the key metrics of a power bank, showing how much power it can hold. Capacity is measured in milliampere-hour, usually marked as mAh. This number can vary drastically from power bank to power bank.

To choose a power bank that will fit your needs, determining the capacity is the first step.

To determine what capacity power bank you need to find out how much power you will need in a typical usage case. Have a look at the battery capacities of the devices you intend to charge from the power bank. Most smartphones today have batteries between 2,500 and 3,000 mAh. You want a power bank that has at least a little more than that.

power bank capacities

The average optimum is around 5,000 mAh capacity. However, power banks of capacity between 2,000 mAh and 20,000mAh are easily available.

It might be tempting to max on capacity, but keep in mind that increasing capacity also increases the size, weight, and price of the power bank. 

Output and speed

The second important technical characteristic of a power bank is the output capacity or charging speed in simpler terms.

This determines the speed with which the power bank will charge your devices. It is essential to know, as low output power may make it look like your device is not getting charged, or worse, your device may use power faster than your power bank will provide it.

There are several standards for the output power:

  • Slow – 5V/1A or 5W;
  • Medium – 5V/2A or 10W;
  • Fast – 5V/2.4A or 12W;
  • Quick Charge – 9V/3A or 18W.
power bank output

It is important to keep in mind that if you choose a Quick Charge power bank, you will be able to charge only QC-compatible devices. Given that QC is one of several fast charging standards, there’s a good chance that you’ll want to charge something incompatible some time or other.

The safest bet here would be fast charging if you’re getting your power bank for universal use. If you’re getting your power bank for a specific device, simply match the V/A parameter of the device.

Size and Weight

Another critical parameter to consider is the power bank’s portability. You don’t want a power bank that is too big or too heavy. However, capacity is tightly connected to size and weight: the higher the capacity, the bigger and heavier the power bank.

This is where you will need to set your priorities and get the optimal combination for your particular use. 

power banks size and weight

Ports and connections

This one is also tightly connected with capacity and size. The lower the capacity, the fewer ports the power bank will have. 

Most of the lightweight and small power banks feature a single port because it doesn’t make sense to split the smaller capacity between several ports. You’re not going to charge several devices with a 3,000 mAh power bank at the same time anyway, so why make many ports?

Larger ones, like 10,000 mAh and above, may have 2 output ports; however, you need a 50K giant to see more than that in most cases.

The older power banks used to have a USB-A port, and many still do, while the new trend is USB-C, just as in other devices. 


Solar or No Solar

There is a distinct type of power bank equipped with solar batteries. This gives a little more independence from the power supply. On the other hand, the solar-powered battery packs are larger and heavier. Not that it is surprising, but still something to consider.

power bank with solar panel

If you’re prone to hiking (or are choosing a power bank for camping and such), a solar power bank makes sense. Still, if you’re not going out in the wild, it might not be such a good idea. The solar power banks are larger and heavier and more expensive and let’s be honest, it’s not like you’re going to set it out in the sun on a typical day in the city.



Power banks range hugely in price. Price point depends on many factors, starting with capacity and quality, ending with additional features and brand name.

While you don’t want to get a 20,000 mAh power bank for something like $10, it definitely will not stand to the quality, but you don’t want to spend $100 on that. As always, it’s all about balance. 


Wrap Up

Picking the right power bank can be tricky. It takes a lot of time and browsing to get an exact match to your wants and requirements. However, being one of the essentials for practical daily life, it is worth the effort.