Power Bank Terminologies Explained: What are mAh, volts, and watts?

Power banks are one of the best gadgets to have in one’s everyday tech arsenal. They allow us to conveniently charge our phones in a pinch and drastically reduce battery anxiety.

But even we can’t deny that terms such as milliamp-hours (mAh), Quick Charge, and other words we normally find on power banks can get a bit overwhelming, especially to the average user. Is having a higher mAh power bank 82 better? Should I pick a 5W or maybe a 25W capable power bank for my new phone?

In this article, we’ll be shedding some light on power bank terminology to better understand what all this battery jargon actually means and hopefully help make your next power bank purchase worth it.

Power Bank Terminologies Explained: What are mAh, volts, and watts?

Before we get into it, let’s get a quick overview of how batteries work. Batteries essentially store a chemical solution that has chemical energy and converts this into electrical energy which we can use to power our machines.

A power bank is a battery that is specifically tailored to be portable and has just a large enough capacity for consumer electronics like smartphones, tablets, and even laptops.

With that out of the way, let’s get into some of the most common power bank terminologies!

Capacity or milliamp-hours or mAh

Perhaps the most common term used to describe power banks, mAh is the main differentiator of these devices. You’ll have 5,000 mAh power banks, 10,000 mAh, or even 20,000 mAh. mAh is short for milliamp-hours, which is a unit of charge that refers to the amount of “charge” that a battery or power bank can hold.

Let’s say that your phone’s battery, which is also measured in mAh, is a cup of water. We can think of a power bank’s mAh as a larger pitcher of water that fills up that cup to charge your phone. The larger your pitcher, the more times you can fill the cup with water.

So, if you have a phone with a 3,000 mAh battery, having a power bank that has a 6,000 mAh will allow you to fully charge it to 100% just around 2 times. The higher the mAh of your power bank, the more times you can charge your device.

The next few terms will be useful to understand charging speeds. Let’s take a look!

Volts (V)

When you see “V” on the back or on top of a power bank, this refers to “volts” or “voltage.” A volt is the standard unit of electric potential and refers to the electrical “pressure” that pushes electricity from one point to another.

Going back to our water analogy, let’s say we have a hose that we use to fill a bucket. Voltage, in this case, is simply the amount of water pressure that pushes the water (or in this case, electric current) forward. When you have a smaller hose, the water pressure is higher thus causing the water to push forward more rapidly, and vice versa. This is the same with voltage.

The higher the voltage, the more pressure will push the electric current from point A to point B.

Ampere (A)

If volts refer to the electric pressure, amperes (A) are the amount of electricity that is flowing from a power bank to your device.

The more amps coming from your power bank, the larger the amount of electric charge that will get transferred to your phone, and therefore – the faster your device will charge.

In our water hose analogy, amps are basically the amount of water that is going through the hose into the bucket.

Watts (W)

Multiplying volts with amps (V * A = W), we get the watt or W. The watt is a measurement of the total energy that a power bank can output at a given time. That’s why you’ll see watts or W in most power bank specifications because this now refers to how much energy it can deliver to your phone to get it charged.

Using the formula, if you have a 10,000 mAh power bank with a 4.8 A output at 5V, your power bank has a power of 24W. This means that it can deliver 24W of power to a phone, for example.

So if you have two power banks, with one that has 10W power and another with 25W, the 25W will definitely charge your phone at a much faster rate because it will have a much bigger power delivery to your device.

In relation to our water hose analogy, we can say that our hose is pointed at a water wheel or water mill that creates energy when it is spun by water. Watts is basically the total amount of power that the water wheel could provide after being spun by the water.

Watt-hours (Wh)

Watt-hour or Wh, on the other hand, is the unit of power that describes the amount of energy used in a period of time. A watt-hour is equivalent to one watt of power that is used in one hour of time.

So as to not confuse Wh and mAh, we can say that Wh is the amount of energy consumed by a power bank while mAh is the amount of charge a power bank can have.

With our watermill analogy, watt-hours will be the amount of water we have spent to spin the watermill, in a given amount of time.

Practically, watt-hours are important to take note of because these are usually how most laptop manufacturers specify their laptops’ battery capacity. Also, most airlines regulate the type of power banks you can carry on a plane, which we have a guide on right here!

Quick Charge

Quick Charge is the name of chipset manufacturer Qualcomm’s fast charging technology. It’s a battery charging protocol that allows you to charge your phone at 10W or more, which provides you with faster charging.

A number of power bank brands support and carry Qualcomm’s Quick Charge technology such as Anker, Aukey, RAVPower, and others, which is why Quick Charge has been pretty synonymous with power banks and fast charging in general.

Power Delivery (PD)

Power Deliver (PD) or USB PD technology allows your device to take in more power through a USB-C port, in a shorter period of time. If your power bank supports PD, it will provide you with faster charging for your phone, tablet, or other devices.

Let’s say you have a phone which can take on 25W of power. If you use a normal 5W charger, which was the industry standard before PD came around, it’s going to take you a while to get to 100%. But if you use a PD-enabled power bank, your phone will get to 100 at a much faster speed.

Output & Input

Output refers to the amount of electricity that the power bank can deliver from its battery cell to your device as it “outputs” electricity from its cell to your chosen machine.

Input on the other hand basically refers to charging the power bank or battery bank itself, instead of your phone or other devices.

Charging Ports

The important thing to note here is that you’ll want to use the output charging port — the port that you’ll use to charge your phone — that provides the fastest charging speed and output possible. Most power banks these days will have two or three different output charging ports that have differing volt-amp combinations.

Also, when power banks have multiple charging ports that could either be USB-A, USB-C, or even Micro USB, each one will usually have a different charging rate and supported charging tech (PD, QC, etc) for that particular port.

The total number of charging ports in a power bank also sort of skews the amount of total W that a power bank has.

For example, a power bank that says it has a max 100W charge does not always mean each port will have a 100W output. Sometimes, when they say 100W, that means one port is 60W, one port is 20W, and another port is 20W — for a total of 100W for the whole power bank.

But don’t worry, power banks almost always have labels next to the ports indicating the volt-amp combination, so you’ll be able to decide which port you’ll want to use depending on your charging needs.

GaN or Gallium Nitride power banks

Lastly, we have Gallium Nitride (GaN) power banks or more commonly known as GaN power banks. These battery banks essentially use gallium nitride semiconductors instead of the usual battery makeup we have in traditional power banks.

Through GaN, we are able to get a power bank that is rated to be three times more efficient, much smaller, and also much faster for charging than usual power banks.

GaN power banks and chargers can output relatively higher W at a very small form factor, making them a pretty popular choice in today’s battery bank scene.

There you go, that will wrap up our quick rundown on some of the most important power bank terms to know! With this, we hope we were able to help you get a better grasp of how power banks, and batteries in general, actually work.

While power bank terms and battery terminology can get a bit confusing at first, it’s pretty useful to know these fundamental terms as you’ll be able to apply them to all your other electronic devices in your house.

With that, if you have any further questions or if you want a more in-depth guide into the world of fast charging, don’t hesitate to comment down below!