Most often, the battery of a mobile device is charged by connecting it to electrical networks. In a situation where access to centralized power supply systems is not possible, an external Power Bank battery will help to charge a dead battery.
Principle of operation
Power Bank - a device for charging mobile gadget batteries, designed for the accumulation, storage and return of electricity. This technique is convenient for traveling, traveling and in places where access to the power grid is impossible.
All energy storage devices have at least two outputs: the first is for charging the device itself, the second is for connecting the battery of a rechargeable mobile device.
External batteries are equipped with one or more storage cells that connect to the controller. The controller board has an output to one or more connectors for connecting and charging mobile devices.
After charging the storage elements, the technician can give electricity through the controller's connectors to the batteries of mobile gadgets.
External battery capacity
The main characteristic of any battery is the capacity, which is measured in milliampere-hours (abbreviated mAh). Its indicator is equal to the maximum amount of electricity that is able to accumulate and store the device. The higher this indicator, the longer Power Bank can charge mobile devices.
This characteristic is crucial for battery selection. In order to calculate the number of possible charges of a mobile gadget, a special formula is used: the capacity of an external battery is divided by the capacity of the gadget's battery and a loss factor of 1.3.
For example, there is an external Power Bank battery of 20,000 mAh and a smartphone with a 4000 mAh battery, you need to divide 20,000 by 4000. The resulting number 5 should be divided by 1.3. It turns out that with the help of the battery, the smartphone can be fully charged 3 times and another time approximately 85%.
Electricity losses are explained by the fact that when it is transferred from an external battery to a mobile device, the voltage rises to the required values. When an electric current enters the gadget's battery, the voltage is again lowered by the built-in controller. Thus, energy losses can range from 20 to 30%.
Amperage
The second most important characteristic of an external Power Bank is current. Measured in amperes (A). From its value depends on how quickly the gadget's battery charges. Before buying, you need to find out what current strength is needed to charge mobile equipment. You can find out from the instructions or by carefully studying the inscriptions on the standard charger supplied in the kit.
The average current required to charge a smartphone ranges from 2 to 3 amperes. It may take up to 4 amperes to charge the tablet’s battery.
Modern external energy storage devices are equipped with a controller that automatically optimizes the output current to the required values. This precaution prevents damage to electronic equipment.
Additional features and options
Manufacturers are striving to equip Power Bank external batteries with additional accessories, connectors and indicators that maximize the functionality of the device. We list some of them:
- built-in additional connectors, characterized by the strength of the output electric current, for charging several devices at once;
- cables and connectors for adapters included to give versatility to an external Power Bank battery;
- indicators built into the case indicating the level of remaining charge;
- a flashlight to illuminate the device and connectors in the dark;
- solar cells for recharging an external battery during daylight hours.
A significant portion of these additional features may be useful.
For ease of use, manufacturers give Power Bank additional options:
- automatic shutdown of the charging process of the mobile device;
- turning off the charge of the external battery.
It is necessary to check with the seller how the external power storage device is charged. Some devices can receive power not only from the outlet, but also from the cigarette lighter, computer port, alternative energy sources.
In order to charge the laptop, you may need a device with a high output voltage (in the range of 16-20 V). Such technical devices are relatively rare.
External device parameters
In addition to the technical characteristics, Power Bank external batteries differ in the following parameters:
- weight and dimensions (depending on the size of the tank and the type of drive used);
- body geometry (cylindrical, round, cubic);
- drive type (lithium-ion or lithium-polymer);
- case material (plastic, metal, etc.);
- design (classic, cartoon, etc.).
When choosing Power Bank, you must give preference to well-known brands. Batteries are complex technical devices, because the risk of buying a low-quality energy storage device of little-known firms is greatly increased.