When you are looking for a phone or a portable charger, you will probably come across the term milliampere-hour or the abbreviation mAh. Not sure what this means? It’s a simple concept and it’s relatively easy to figure out what you need.
What are Milliamp Hours?
Milliamp hours is a unit that simply measures power over time, with the abbreviation mAh. To get a better idea of how this works, let’s look at what milliamps are.
A milliamp is a measure of electrical current, specifically one-thousandth of an ampere. Amperes and milliamps measure the strength of an electrical current. Add hours to this and you get a measure of how long this current can flow at that strength.
Think about a battery as an example. If that battery can sustain a current output of one milliamp for 1 hour, you could call it a 1 mAh battery. A milliamp is a small amount of current, so this battery wouldn’t be very practical.
In practice, we see mAh used in every electronic device with a battery, from phones to Bluetooth speakers† These devices range from hundreds of milliamp hours to thousands in terms of capacity, but they are all measured in the same way.
One thing to note here is that milliamp hours is just a measure of capacity. They don’t control how fast your charger will charge a particular device. This varies by charger depending on a number of factors, such as whether they support fast charging†
Milliamp hours and charging capacity
The average smartphone nowadays has a battery capacity of 2,000 to 4,000 mAh. These are much larger batteries compared to flip phones and older smartphones. But as phones have become more sophisticated, the demand for batteries has increased, and thus decreased battery life general. This means portable chargers are more popular than ever.
To be really useful, you want a portable charger that has at least as much battery capacity as anything you want to charge. After all, an older charger with a capacity of 2,000 mAh won’t do much for an iPhone 13 Pro Max with a 4,352 mAh battery.
A charger with about the same capacity as your phone or tablet is better than nothing, but in this case bigger is almost always better. Even if you’re not using your charger’s maximum capacity, it’s often better to have the extra juice and not need it than to miss it.
That said, needs can vary widely between people. If you want charge your smartphone while camping, you’ll want a higher-capacity charger, as you’ll likely have fewer (if any) options for charging. Look for something in the neighborhood of 20,000, especially if you plan on making longer trips.
If, on the other hand, you occasionally find yourself needing a bit of an upgrade at the end of the day, a 10,000 mAh charger will do the trick for your needs.
Is there such a thing as too much capacity?
The capacity of the charger continues to increase as the batteries of our devices grow. With that in mind, is it possible to have a charger with too much capacity for the devices you’re charging?
While there are some drawbacks to a larger payload, there aren’t many, and none of them are dangerous. Having a charger with far more milliamp hour capacity than you need will not damage your devices.
The main drawback of a charger with more capacity than you need is size. More capacity means bigger batteries, which sometimes need more space for cooling, giving you a much larger charger. This can be inconvenient if you take a charger on a backcountry hikebut smart packaging can solve this problem.
The other drawback of a larger capacity battery is that it can take longer to charge. This is often not as bad as you may think, but if you use a charger on a daily basis, you probably want it to charge quickly.
If you’re in a hurry and don’t want to look up your phone’s battery capacity to choose a charger, take a look at our overview of the best portable phone chargers† While you’re at it, you might want to make sure you Charger is also sniffing.