Menu Close

Complete guide to choosing the right external phone battery


We use our smartphones and tablets most of the day to check our emails, watch videos, calls, SMS, social networks, listen to music … Despite the capacity of their internal battery, it is difficult to finish the day by using your phone extensively. . It is therefore essential to acquire and choose your external battery (power bank) in order to be protected from this inconvenience. This article aims to answer the question of how to choose your backup battery. For this, you need to know the purchase criteria to consider and the types of external batteries in the market.

What is an external battery?

An external battery or backup battery or power bank is a portable device that allows you to recharge, wherever you go, your mobile phone, but also other devices such as your tablet, game console, etc. But first, you have to recharge the external battery so that you can also recharge your devices as soon as the need arises.

There are several types of back-up batteries, the prices of which are between 15 and 60 $. The budget is certainly a criterion to consider, but it is crucial to first define your needs. Do you have a habit of using your phone intensely all day outdoors? Do you travel regularly?

In this case, you will need a large capacity between 10,000mAh and 20,000mAh. Do you use your phone less and like to go out light? A slim battery or pocket battery with a capacity of 5000 mAh might be sufficient.

The purchase criteria for choosing the right external battery

So, before considering any purchase, you must take into account a number of criteria that will help you choose an external battery .

The capacity

Note that the milli-ammeter (mAh) is the unit of measurement for the amount of energy stored in the external battery. To choose the right external battery , you must opt for one that has a capacity twice the capacity of the phone or any other device to recharge. An 1800 mAh model stores less energy than a 3000 or 5000 mAh model.

Larger capacity models usually have multiple USB ports and can charge multiple devices at once.

NB : A battery cannot be completely drained of all the stored energy because it uses part to function and another is lost during charging.

By way of illustration, this table will allow any reader to find out how to choose the right external battery according to the device to be recharged.

iPhone 8iPad Mini 4
iPhone XiPad Pro 2018
iPhone XRGalaxy tab s3
iphone xsGalaxy tab s4
Galaxy s8Huawei Mediapad T5
Galaxy s9 plusHuawei MediaPad M5
Galaxy s10 plusXiaomi mi pad 4
Huawei p20 proAmazon Fire HD 2018
Huawei mate 20 proLenovo Yoga Tab 3 Plus

In view of this table, one can wonder which external battery for smartphone would be the most appropriate. To this question, it should be noted that it is important to choose a battery with at least double the capacity of your phone to guarantee a full recharge.

Regarding the purchase cost, it depends on the capacity of the external battery, the brand and the options included (fast charging, presence of several USB ports, etc.). The prices for back-up batteries vary between $ 15 and $ 100, or even more.

NB : However, the battery cases are more ergonomic than the external batteries, because there is no loss of energy during the transfer of this one from the external battery to the device to be recharged.


Nowadays, many people use devices or gadgets that charge via USB. The intensity of these USB ports is expressed in Amperes (A). This intensity is very important because it determines how quickly the battery will charge your device.

Note that smartphones are recharged with a 1 Amp USB port while tablets use those of 2A, 1A or 2.4A in order to be able to recharge quickly. It is therefore wise to choose batteries with output USB ports at least equal to the capacity indicated on the original charger of your device.

For a diverse use on several devices like Huawei, iPhone, Samsung… it is preferable to choose its backup battery with a capacity of at least 5V / 2 Amps.

Its technology must be SMART

SMART technology allows the external battery to automatically detect the device connected to its output USB port and adapt to its charging speed.

This amounts to saying that if the full recharge time (100%) is 3 hours for a conventional battery, it will be 2 hours for a SMART battery.

The purpose of the SMART battery is to provide the maximum amperage according to the device in order to recharge it quickly. This characteristic is mentioned on the product sheets, if the battery has one.

Choose your external battery according to the type

Choosing the right external battery requires taking into account different types of batteries. There are standard external batteries and battery cases

Standard external batteries

Standard external batteries come in many shapes, including ultra-thin, travel, shockproof, round. They can have one or two integrated USB ports depending on the use and the device to be recharged.

If you have to carry your external charger in your bag on a daily basis, it is advisable to take a battery of around 10,000 mAh fitted with one or two USB ports. Smaller and more discreet.

On the other hand, if you go on a trip most often and you have a phone, tablet or APN, choose a battery with a capacity greater than 15,000 mAh with two USB ports. You will be able to charge your two peripherals jointly.

Battery cases

There are also protective shells incorporating a battery . These battery cases will extend the autonomy of the device, but the downside is that they adapt to a single model of smartphone.

NB . If you change your smartphone, you must change the rechargeable case.

Wireless chargers

Wireless chargers belong to Magnetic Induction (Qi) technology and have become very popular. Magnetic induction technology, created in 2008 by an international business corporation for the promotion of world wireless energy standards (Wireless Power Consortium), has some advantages, but also drawbacks. If it does not need a USB cable to charge which sometimes clutters for its use, on the other hand its charging time is slow compared to that of a conventional external charger.

Its use is very simple. All you need to do is place your phone so that it is in contact with the wireless charger terminal for energy transfer.

It should be noted that there are also other standards such as “Air Fuel” chargers. Hence it is advisable to opt for a Qi standard because many phones currently in use are rather Qi certified.

Finally, it is essential to check the mAh capacity of these Qi chargers which must always be twice as large as your phone. In addition, always buy wireless chargers from authorized sellers, as we are not immune to counterfeiting. Before ordering, please make sure it is Qi certified.

Solar chargers

Our greatest wish is to keep our phone charged during the day. We are not there yet, but with the advancement of technology, there are already solar chargers which are of no less negligible contribution. The solar charger is a device made up of one or more sheets of solar panels . Each of these panels has photovoltaic cells that are either monocrystalline or polycrystalline.

Monocrystalline panels are dark in color. They attract more solar rays. They are able to capture even the slightest solar energy during cloudy days or with low radiation. While the blue colored polycrystallines are recommended for days with strong radiation or full sun.

However, it should be noted that the use of solar sheets depends on the temperature of the day . So there is no such thing as a perfect charger for the whole year.

To choose the right induction charger, you must always take into account the price, quality and power. If the output power of the charger is large, the recharging of the connected devices will be fast , as the USB ports will have a greater capacity to meet the energy demand of each connected device. Finally, for your phone, it is advisable to buy a solar charger whose capacity varies between 15 to 20 W.

In short, the choice of an external battery for your phone therefore depends on several parameters. The price, the capacity in mAh, the size, the design, the brand… However, you must think about determining your needs before purchasing the most appropriate type of backup charger.