How to choose an external battery

Modern mobile devices, smartphones and tablets are productive devices that suit almost everyone, except for one thing – the battery charge lasts for a short time, and it usually sits down at the most inopportune moment. To be able to recharge the phone directly in the field, external batteries are intended, or power banks, as they are also called. It is for this reason that the choice of an external battery must be approached with all responsibility.

choose an external battery

Top powerbank manufacturers

Choosing a portable battery, preference should be given to the leaders of the microelectronics market, whose range includes a large number of similar devices:

  1. Meizu;

  2. Xiaomi;

  3. Samsung;

  4. Toshiba;

  5. Acer;

  6. Nokia;

When choosing a powerbank, one should take into account both the technical characteristics of a particular device, form factor and capacity, as well as reviews and opinions that have developed about it during long-term operation. In some cases, this information will be decisive for a particular buyer, rather than beautiful numbers in an advertising brochure.

Types of portable batteries

Despite the general principle of operation and purpose, power banks are divided into the following conditional groups:

USB rechargeable batteries

USB rechargeable batteries

The classic form factor, which assumes the presence of two separate inputs – one of which serves as an output and is intended for charging connected devices, the second is an input and is designed to replenish the capacity of the powerbank itself. They replenish energy both with the help of a computer USB port, and with 220 and 12 volt networks with appropriate adapters.


  • Decent functionality;

  • Charged from USB, an ordinary socket or car cigarette lighter;

  • Capable of providing up to 5 full charge cycles for a mobile phone or other similar devices;

  • Compact dimensions;


  • High-quality devices are expensive;

  • They turn out to be useless when discharged away from the outlet;

Powerbanks equipped with a built-in dynamo

Powerbanks equipped with a built-in dynamo

Devices, the principle of which involves recharging not only by means of an external power source, but also by means of a built-in dynamo. For this purpose, a special handle is used, turning which, the user generates electricity, which is used to charge the battery. The rest of the device is identical to classic power banks.


  • Small dimensions and minimal weight;

  • Variety of options, differing in size, battery capacity and functionality;

  • Charging thanks to the USB port, as well as the built-in dynamo;


  • More expensive than conventional options;

  • Tendency to failure of the mechanical part of the device;

  • The renewal of energy by the dynamo is quite slow;

Batteries with built-in solar panel

Batteries with built-in solar panel

They are recharged not only from the USB connector, but also using the energy of the sun. For this purpose, a special solar panel is used, located on the outside of the device.


  • Small size;

  • Various models for the size and capacity of the battery;

  • Charging from 220 and 12 volt networks, as well as using solar energy;


  • Expensive;

  • Are slowly charged by the sun;

  • They turn out to be useless in cloudy weather and at night;

Portable Battery Selection Options

external battery selection criteria

Built-in battery capacity

The main criterion responsible for how many cell phone charging cycles the powerbank will withstand without the need to recharge. It is measured in milliamperes per hour – a traditional value common to all electronic devices. To determine the approximate life of the device, you need to divide its capacity by the battery capacity of the smartphone being charged, rounding the resulting value to whole numbers.

If your iPhone has a 3000mAh battery and your portable powerbank is equipped with a 15,000mAh 'battery', the number of full charge cycles will be between 4 and 5 depending on the outside temperature and operating conditions.

You should also pay attention to the correspondence of the real and declared capacity figures. This is very often the fault of Chinese manufacturers, presenting “weak” power banks as powerful devices. It is for this reason that it is strongly discouraged to buy the cheapest models;

Features of choosing an external battery for a phone by the strength of the output current and voltage

The output current of the USB port is the main parameter that determines the charging speed of the connected device.

  1. Headlamps and other compact devices that do not have a large battery do not require excessive output current. A value of 500-750 Mili-amperes is sufficient for fast charging;

  2. Action cameras, cameras, push-button mobile phones will require 1-1.2 Ampere output current for fast charging;

  3. Smartphones, tablets and other electronic equipment can be effectively charged only from a current of 2-2.5 Amperes. The use of a source with a lower power will stretch the energy replenishment time up to 100% up to 4-5 hours;

As for the charging voltage, all modern microelectronics is designed for a current of 5 volts. The use of a lower voltage is not able to provide efficient charging of the battery, while a higher current can cause instantaneous failure of the power controller.

Features of choosing an external battery for a smartphone according to the availability of additional options

Recharging a smartphone battery is far from the only function that modern power banks can provide. There are devices on sale that have:

  1. Built-in flashlight;

  2. MP-3 – player, FM-transmitter and built-in radio;

  3. Flash drive with a capacity of 18 to 256 GB;

  4. Moisture-resistant and shockproof housing;

  5. The above functions are a nice addition, and if we consider the powerbank from the standpoint of the main function, the primary importance is the capacity of the built-in battery, the output current power and charging methods.

In the following articles, our experts will tell you how to choose an iphone battery and the secrets of choosing a battery capacity.

Attention! This material is the subjective opinion of the authors of the project and is not a purchase guide.

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