How to Choose an External Battery: Your Complete Guide to Buying a Power Bank


Smartphones and other gadgets have become such an integral part of our lives that a turned off smartphone can wreck our schedule. Even large capacity cell phones will drain their battery if you forget to charge them.

The need for an external battery can arise at any time. Whether it’s a short circuit in an emergency or a long distance trip with no shots in sight, a power bank will help keep your digital devices powered on the go.

There are many types of power banks, and not all are the same. If you are wondering how to choose a power bank for your iPhone or precious tablet, keep reading.

In our guide, we’ll tell you how to choose the right external battery. At the same time, you are also going to find out what are the main features to consider, and what are the essential and additional functions to look for first.

Main characteristics of external batteries to consider

All external batteries have common features. In this section, we walk you through their main features. Understanding the differences between the functions will help you make the right choice.

Choose the right capacity for a full recharge

The milliampere-hour (mAh) indication lets you know the capacity of the external battery. This value helps you determine what you can use it for. Higher charging capacity will have higher mAh value.

The latest models of iPhone and Android smartphones have large capacity batteries, over 3500mAh. Therefore, to fully charge these devices, you need an external battery with a capacity of at least 5000mAh. On the other hand, the capacity of a tablet tends to exceed 5000mAh. From this perspective, it will not be able to be satisfied with such a small power.

Your choice of capacity depends on the charging needs of your gadgets and devices. Consider which devices you need to charge and how many full charges you want to get when choosing capacity.

Choose the right charging speed to get things done quickly

External batteries have two types of charge levels, input and output. The input charge level determines the time it takes for portable chargers to recharge their batteries. On the other hand, the output level is the charging speed at which the external battery will charge your device.

Voltage (V) and Amperage (A) define the charge levels of your portable battery. Voltage regulates the charging process, while amperage determines its speed. The following table simplifies the selection process based on the output load speeds.

Slow charge5V / 1A
Average load5V / 2A
Fast charge5V / 2.4A
Quick Charge9V / 3A

The fast charge level is the most common. These models offer almost the same performance as a wall outlet and have a higher preference than their slower counterparts.

Although the models with the Quick Charge function are the fastest on the market, they are not compatible with all devices, especially not with your iPhone. External batteries must have dedicated Quick Charge ports, and devices must have Quick Charge technology to exploit this speed.

Choose the right size power bank to ensure proper portability

While external batteries are considered portable chargers, features like higher charging capacity, ability to charge multiple devices etc. can influence their size.

However, technological progress has made it possible to develop mini external batteries with a large capacity.

If you are wondering how to choose an external battery for your phone, besides the capacity and charging speed, also consider its portability. Compact and slim power banks are the ideal choice if portability is a priority.

Choose the right number of ports when sharing

The number of USB ports for an external battery depends on its size and capacity. Multiple charging ports are often available with large, high capacity portable chargers. These are ideal when you need to charge multiple devices, as most of them allow simultaneous charging.

When purchasing a portable multi-port charger, consider the output level of each port. As we mentioned, the output charging speed determines how fast your device charges.

Another aspect to be aware of is that when you charge devices simultaneously, your power bank may not be delivering high current to all ports. So, simultaneous charging can slow down the overall charging process.

Choose the right type of battery to get the most out of it

There are mainly two types of battery technologies. Lithium-ion batteries are high power density batteries that often lack memory effect. As they tend to lose performance over time, they are priced significantly lower than lithium polymer batteries.

The lithium polymer battery is the best option when it comes to charging. These batteries, although relatively expensive compared to lithium-ion batteries, tend to be more flexible and rugged.

Lithium polymer batteries are lightweight and take up little space. These batteries have a lower risk of electrolyte leakage and last much longer than other batteries.

Look for additional features to get the most out of an external battery

Power banks are basically batteries that store the electrical energy your devices need. The security characteristics must therefore be taken into account.

Additional features that allow you to use your power bank for more than just charging your devices are also welcome. You can find portable chargers with a host of handy features that double their usefulness.

In this section, we discuss some additional features that you may want to look for when purchasing a power bank.

Charging and protection functions for more safety and efficiency

You can plug your device into your external battery and forget about it. A high capacity portable charger can continue to charge your device even if it is fully charged.

For the health of your device, never overload it. Although many smartphones and other gadgets come with built-in security technology, it is still a good idea to buy a power bank with security features.

Look for safety features that include overcurrent, surge, and overload protection. Also check the safety certifications on the packaging to make sure your new gadget meets standard safety protocols.

External battery cables for a perfect match with each device

It seems like a no-brainer, but you might just forget about it altogether. When purchasing a portable charger, check if it comes with cables and if those cables are compatible with your devices.

If you intend to charge your iPhone, an iPhone compatible cable is a necessity. Likewise, fast-charging power banks need Lightning cables to allow you to quickly charge your devices. Also consider your USB cables. The USB charging cable to your laptop may be different from your tablet.

Look for cables with detachable magnetic connectors for Lightning, Type-C, and MicroUSB. They could be a great option to reduce the number of cords without limiting the range of applications of an external battery.

Another cable to consider is the external battery charging cable itself. Remember that wall outlets differ in some countries. Therefore, your external battery charger may not be suitable for travel. Consider investing in a universal travel adapter.

LED lights and display screens to know when to recharge the battery

External batteries, like any other electronic device, need a full recharge before they are ready for use. Look for power banks that have LED indicators or display screens that let you know when you need to charge them.

Carrying an incompletely charged or fully discharged battery will not do you any good. The indicators will help you know how much battery capacity you can use.

Portable hand warmer for cold weather

A power bank that does more than charge your camera while on vacation is an asset to us. You can find models that incorporate hand warmers. This additional function makes it possible to go from a simple charger to a versatile gadget.

Wireless power bank for a wireless experience

The latest technology in smartphones is the Qi charging function. This feature allows you to charge your smartphone wirelessly, thus eliminating the drawbacks of wired charging.

The latest portable chargers feature wireless charging for Qi-enabled devices.

Solar charger to harness the sun’s energy

If you like off-grid adventures, a solar battery might be the best bet. Besides being environmentally friendly, portable solar chargers tend to be extremely durable.

These outdoor use gadgets feature sturdy construction to improve durability and weather resistance. They also include additional features like LED lights. However, they can sometimes be bulky given their many characteristics.

Customize your external battery to get a unique gadget

When you buy a power bank, you don’t have to settle for the same old designs, with a metallic finish or a dull black. Give your future portable charger a facelift and infuse it with uniqueness through our 2-minute personalization process .

Create a truly unique power bank case with your favorite photos or any other image in just three easy steps.

Step 1: Select Gadgets as the device type.

Step 2: Select the type and model of gadget.

Step 3: Upload your image.

Before finalizing your order, check the appearance of the shell in our preview window. Click on “Buy” and your personalized external battery case is ready. It is also an ideal gift!

Energy in motion!

Let’s summarize the main points to consider when looking for external batteries to charge your devices:

  • Take the capacity of the battery into account. Choose a higher capacity than your device’s battery to get at least one full charge.
  • Look for 5V / 2.4A output levels for fast charging and 9V / 3A for a Quick Charge external battery.
  • Make sure a Quick Charge portable charger comes with dedicated ports and cables. Also, make sure your device supports Quick Charge technology.
  • Whenever possible, opt for external lithium polymer batteries, as they last longer.
  • Choose an external battery with safety certifications and protective features against overcurrent, overvoltage and overdischarge.
  • Consider the portability and primary use of your external battery. Choose a power bank that matches your lifestyle.
  • Look for LED indicators or displays that let you know when your small powerhouse needs recharging.

Do you want more ?

Now that you know what to look for when buying a power bank, are you wondering which one to choose? Do not worry ! We’ve got you covered. Visit our blog The 10 best external batteries for a powerful 2021 to find the best external battery, so that your smartphone never runs out of power.

Please don’t hesitate to contact us if you want to find other external batteries or smart gadgets that make daily life more efficient!