The right capacity depends on what you want to charge and how often you want to top up without access to a wall socket. For daily use, a compact power bank is often enough, while for multiple charges or more demanding devices you will need more mAh. On this page, you can quickly see which capacity suits your usage.
What does mAh mean for a power bank?
mAh stands for milliampere-hour and indicates how much energy a power bank can store. The higher the mAh rating, the more often you can charge a device before the power bank itself needs recharging. A higher capacity usually also means a larger size and more weight, so the best choice is not automatically the highest value.
It is important to know that the stated mAh capacity is a theoretical value. In practice, some energy is always lost during charging, for example through conversion and heat. As a result, you usually will not get exactly the number of full charges you might expect based on a simple calculation.
How many mAh do you need?
For most choices, you can base your decision on your usage situation. If you only want to top up a phone on the go, you need less capacity than if you will be away from a wall socket for several days or use multiple devices at the same time.
| Usage situation | Recommended capacity | Practical explanation |
|---|---|---|
| A short extra boost during the day | 5,000 mAh | Useful for light daily use and easy to carry |
| Charge your smartphone 1 to 2 times | 10,000 mAh | A good middle ground between portability and extra capacity |
| Multiple charging sessions or intensive use on the go | 20,000 mAh | Suitable for travel, long days or multiple devices |
| Heavier charging via USB-C/PD | 20,000 mAh or more, depending on the device | Relevant if power output and compatibility also matter more |
How many times can you charge your phone with a power bank?
The quickest way to estimate that is with this simple calculation:
power bank capacity ÷ phone battery capacity = theoretical number of charges
For example, if your smartphone has a 4,000 mAh battery and you use a 10,000 mAh power bank, you theoretically get 2.5 charges. In practice, the result is lower because of energy loss. So it is better to assume a practical yield that uses around 70 to 85 percent of the stated capacity.
That means the same 10,000 mAh power bank will often be good for about 1.7 to 2 full charges of a phone with a 4,000 mAh battery in real use. That is a much more realistic starting point when comparing models. Is your phone battery draining faster than expected? Read: Phone battery draining fast? Causes and tips.
Practical examples
- 5,000 mAh power bank - usually suitable for charging an average smartphone about once
- 10,000 mAh power bank - often suitable for about 2 charges, depending on the phone
- 20,000 mAh power bank - suitable for multiple charges or use with several devices
What is the difference between 5,000, 10,000 and 20,000 mAh?
5,000 mAh
A 5,000 mAh power bank is especially suitable as a backup for when you are on the go. This size is ideal if you want a compact solution for emergencies, commuting or a night out.
10,000 mAh
For many users, 10,000 mAh is the most practical middle class. You get clearly more flexibility than with 5,000 mAh, without immediately moving to a larger model. This is often the best choice if you are regularly on the go and want to be sure you can recharge your smartphone one or more times.
20,000 mAh
20,000 mAh is especially interesting for long travel days, holidays, intensive use or multiple devices. This type of power bank is less compact, but offers much more backup power. At azcom.nl you will find Power banks and chargers in 5,000 mAh, 10,000 mAh and 20,000 mAh, among others, so you can choose based on your usage rather than only on the highest capacity. If you are flying with a power bank, check the rules in advance: Taking a power bank on a plane: rules and limits.
Do not look at mAh alone
Capacity is important, but it is not the only selection criterion. The connection type and charging speed also determine whether a power bank is a good match for your device. Especially with newer models, USB-C or Power Delivery can be relevant if you want faster or heavier charging with the right Charging cables and accessories.
If you use multiple devices or choose a magnetic power bank, the basic question stays the same: how much energy do you really need per day or per trip? So start with the desired capacity and only then look at size, ports and extra features such as MagSafe accessories.
Which capacity suits your situation best?
- Choose 5,000 mAh if you mainly want a compact backup
- Choose 10,000 mAh if you want a strong all-round choice for smartphone use
- Choose 20,000 mAh if you want to go longer without a wall socket or charge more than one device
If you are unsure between two capacities, do not automatically choose the largest. The best power bank is the one that matches your daily use, desired portability and the number of charges you really need. When on the go, many users also look at practical accessories such as phone protection alongside charging solutions.
Frequently asked questions
How many mAh should a good power bank have?
For general smartphone use, 10,000 mAh is a logical choice for many people. If you only want a compact emergency solution, 5,000 mAh may be enough. For longer trips or multiple devices, 20,000 mAh is often more suitable.
How long does a 10,000 mAh power bank last?
That depends on your phone battery and the energy loss during charging. With an average smartphone, 10,000 mAh often delivers around 1.5 to 2 full charges in practice.
Is a 20,000 mAh power bank good?
Yes, if you need a lot of capacity. A 20,000 mAh model is especially suitable for intensive use, travel or situations where you want to charge multiple devices. For only a small daily backup, this size may actually be larger than necessary.
What is better: 50,000 mAh or 20,000 mAh?
Not necessarily the highest capacity. For many users, 20,000 mAh is already more than enough and often more practical to carry. A larger capacity is only better if you really need that extra reserve.