What is mAh in Batteries?

Written by: Pete Luckhurst



Time to read 6 min

In the world of batteries and power banks, one term that often comes up is "mAh". But what exactly is mAh? How does it impact the performance of batteries? And why is it important to choose the right mAh for your device? In this article, we will delve into the details of mAh and explore its significance in the world of batteries.

What is mAh?

So what is mAh in batteries? mAh, which stands for milliampere-hour, is a unit used to measure the capacity of a battery. It represents the amount of energy the battery can store and deliver over time. Essentially, the higher the mAh rating of a battery, the more energy it can hold, and the longer it can power a device.

For example, a battery with a mAh rating of 2000 can deliver a current of 1 milliampere (mA) for 2000 hours or 2 milliamperes for 1000 hours. In simple terms, mAh provides an estimation of how long a battery can power a specific load before it needs to be recharged or replaced.

It's important to note that the mAh rating is just one aspect to consider when evaluating a battery's performance. Voltage, temperature, and discharge rate are also factors in determining how long a battery will last in real-world usage scenarios.

When comparing batteries with different mAh ratings, it's essential to consider the specific requirements of the device they will be powering. A device that requires a higher current draw will deplete a lower mAh battery more quickly than a higher mAh battery, even if both are fully charged.

Importance of mAh in Battery Performance

The mAh rating plays a crucial role in determining the overall performance of a battery. Devices that require high power consumption, such as smartphones or gaming consoles, often require batteries with higher mAh ratings to ensure longer usage time.

Besides the duration of usage, the mAh rating also affects how quickly a battery can deliver power. Batteries with higher mAh ratings can handle higher current demands, making them more suitable for devices that require quick bursts of energy, like cameras or power tools.

As mentioned, it's important to note that the mAh rating is just one factor in determining a battery's performance. The chemistry of the battery also plays a significant role in how efficiently it can convert stored energy into usable power. Lithium-ion batteries, for example, are known for their high energy density and long cycle life, making them a popular choice for many electronic devices.

Additionally, the temperature at which a battery operates can impact its overall performance. Extreme temperatures, whether too hot or too cold, can reduce a battery's efficiency and lifespan. This is why some devices, like electric cars, are equipped with sophisticated thermal management systems to regulate the battery temperature and optimize performance.

How to Calculate mAh for Different Batteries

To calculate the mAh rating for different batteries, you need to consider the voltage and capacity. The basic formula is:

  1. Calculate the watt-hours (Wh) by multiplying the battery's voltage in volts (V) by its capacity in ampere-hours (Ah).
  2. Convert the watt-hours to milliwatt-hours (mWh) by multiplying them by 1000.
  3. Finally, divide the milliwatt-hours by the battery's voltage to obtain the mAh rating.

For example, if you have a battery with a capacity of 2 Ah and a voltage of 3.7 V, the calculation would be:

(2 Ah) x (3.7 V) = 7.4 Wh

7.4 Wh x 1000 = 7400 mWh

7400 mWh / 3.7 V = 2000 mAh

Therefore, the battery would have a mAh rating of 2000.

The Difference Between mAh and Ah

While both mAh and Ah are measurements of electrical charge, they differ in magnitude. Ampere-hour (Ah) is the unit used for larger batteries, such as those found in electric cars or solar power systems. One Ah is equal to 1000 mAh. So, a battery with a mAh rating of 5000 would have an Ah rating of 5.

It's essential to understand this difference when comparing batteries or considering the power requirements of different devices.

Choosing the Right mAh for Your Device

Choosing the right mAh for your device depends on several factors. Consider the power requirements and usage patterns of your device. If you use it extensively throughout the day or require high-powered functions, opt for a battery with a higher mAh rating to ensure longer usage time.

However, bear in mind that higher mAh batteries are typically more substantial and may take longer to charge. Therefore, strike a balance between capacity and practicality based on your specific needs and preferences.

Common Misconceptions about mAh in Batteries

There are a few misconceptions surrounding mAh in batteries that should be clarified. Firstly, although a higher mAh rating indicates a longer runtime, it doesn't necessarily mean better overall battery life. Other factors, such as battery chemistry and device efficiency, also impact battery longevity.

Secondly, some believe that using a battery with a higher mAh rating than recommended for a device will improve its performance. However, this is not the case. Using a battery with significantly higher capacity can lead to compatibility issues and may not provide any noticeable benefits.

It's essential to do proper research and refer to the manufacturer's recommendations when selecting a battery for your device.

Practical Tips for Maximizing mAh in Your Devices

To maximize the mAh in your devices and prolong battery life, here are some practical tips:

  • Reduce screen brightness and timeout settings.
  • Limit background app refresh and disable unnecessary notifications.
  • Close or force-stop apps running in the background.
  • Turn off connectivity features like GPS, Bluetooth, and Wi-Fi when not in use.
  • Lower the volume or use headphones instead of built-in speakers.

By implementing these simple practices, you can make the most of the mAh in your batteries and ensure that your devices stay powered for longer durations.


mAh is a crucial factor to consider when choosing batteries for your devices. It represents the capacity of the battery and impacts the runtime and performance. By understanding mAh and its significance, you can make informed decisions when purchasing batteries and maximize their potential. Remember to consider the power requirements of your device, strike a balance between mAh rating and practicality, and follow the manufacturer's recommendations for optimal battery usage. By doing so, you can ensure that your devices remain powered for longer, enhancing your overall user experience.


What is mAh and why is it important for batteries and power banks?

  • mAh stands for milliampere-hour, a unit used to measure the energy capacity of batteries and power banks.
  • It indicates how much charge a battery or power bank can hold and how long it can power your devices.

How does the mAh rating affect the performance of batteries and power banks?

  • Higher mAh ratings typically mean longer battery life and more charging cycles.
  • When choosing batteries or power banks, consider your device's power requirements and your usage habits.

Is a higher mAh rating always better?

  • Not necessarily. While higher mAh ratings offer longer battery life, they can also lead to bulkier and heavier batteries or power banks.
  • Consider balancing mAh with other factors like portability and price when making your selection.

How can I calculate the battery life of my device based on its mAh rating?

  • Divide the device's mAh rating by the mAh rating of the battery or power bank you're using.
  • Multiply the result by the battery's voltage (usually 3.7V for lithium-ion batteries).
  • This gives you an estimate of the hours your device can run on a single charge.

mAh Definition: Milliampere-hour (mAh) measures battery capacity, indicating the energy a battery can store and deliver over time.

Calculating mAh: Multiply battery voltage by capacity to get watt-hours (Wh), then convert to mWh. Then divide mWh by voltage to obtain mAh rating.

Choosing the Right mAh: Consider device power requirements and usage patterns. Balance between higher mAh for longer usage and practicality (size, weight, charging time).

Common Misconceptions: Higher mAh doesn't always mean better overall battery life. Using significantly higher mAh batteries than recommended can cause compatibility issues.

Maximizing mAh: Adjust screen brightness and timeout settings, manage background apps and connectivity features, or lower volume or use headphones to conserve battery.

About the author

Pete Luckhurst is a Website Manager at Maplin.

After getting an early start in the world of computing with C64 & Amiga computers, Pete now spends much of his spare time in PC VR and dabbling in game development. He also has a strong interest in film, photography and music.

Among other endeavours, he previously worked in a Maplin store, so it was a no-brainer when the opportunity arose to work on the modern incarnation of Maplin online. Besides writing for the blog, Pete works alongside the Maplin team to help keep the online store running smoothly.