The main characteristic of a bank is its capacity, so you should always pay attention to this parameter when buying a new device.
During the operation or purchase of such a product from hand, it becomes necessary to check the product, that is, determine the ability to accumulate a certain amount of electricity. This article will explain in detail how to measure the capacity of a bank in various ways.
Content
What power supply is in the Power Bank
Before you begin to measure the capacity of a portable energy storage device, you need to know exactly how the device is arranged. The power bank consists of a thin case in which several ordinary cylindrical batteries are installed, which are connected together in parallel.
In this case, the capacities of all the elements add up, which allows you to charge a smartphone or phone several times in a row from such a product without resorting to installing a portable battery for charging.
In addition to batteries, there is a controller in the bank that will turn off the charging of elements when a certain level is reached. Also, many devices are equipped with a light indication showing the level of charge or discharge of internal batteries.
As a rule, rechargeable lithium batteries are installed in banks. 18650 batteries. Depending on the manufacturer, the capacity of such power sources may vary significantly. For this reason, it will be useful to control this parameter during operation or immediately after the purchase of a bank.
Where is the declared capacity indicated
The capacity of the 18650 battery cells is always indicated on the body of the power source, but for this purpose it will be necessary to disassemble the product. Such a procedure cannot be carried out without the use of brute physical force, which can cause irreparable damage to the appearance of the product.
It is much easier to determine the capacity declared by the manufacturer by studying the operating instructions. On the packaging, this information can also be duplicated, so if the original box from the bank is preserved, then you can easily determine the nominal value of this parameter of the external battery.
How to check the capacity of a bank
The capacity of the bank can be checked in several ways. The most popular method is the multimeter method.
Using a multimeter
The multimeter is a universal device with which you can easily measure resistance, voltage or current. You can also determine the capacity using this device, but for this you need to perform not only measurements of certain parameters, but also perform some arithmetic operations.
To check the capacity, in addition to a multimeter, you will need to select a load, for example, a small electric motor or an incandescent lamp.
You will also need to connect an ammeter between the bank and the consumer of electricity. The resulting value should not exceed the maximum specified in the documentation for the portable battery.
Knowing the discharge current, in order to obtain the product capacity in mAh, it is necessary to find out the real time of the device from a fully charged power bank. After one hundred percent charge, the load is connected to a portable power source and a timer is activated.
The check stops when the device stops working at full power (the incandescent lamp dims, the motor reduces the speed, etc.). To determine the capacity, the resulting time in hours is multiplied by the current in amperes.
Via usb tester
As a rule, banks are equipped with a standard usb connector, so you can use special testers to determine the capacity. Such devices are compact and inexpensive.
Unlike the above method, where it was required to calculate this parameter, when using a usb tester, it is enough to connect it to the circuit between the charger and a fully discharged bank. When charging is complete, the device will show on the digital display the actual capacity level of the internal batteries.
The advantages of this method are its simplicity and high speed of measurement. In addition to capacity, such devices can show in real time the voltage and strength of the current consumed.
With Smart Charges
This method will require removing the batteries from the casing of the bank. For this purpose, you must carefully disassemble the portable product. Then unsolder or disconnect the batteries and install them in the charger. Such a method should be chosen only if the first two methods are impossible for one reason or another.
After installing the batteries in the charger, they are fully charged, after which the built-in program will accurately calculate this parameter. If all the batteries in the power bank were connected in parallel, then to obtain the exact value of this parameter, you will need to add the capacity value obtained from each element.
How true is the claimed data?
Unfortunately, the parameters stated on the packaging or passport of the bank very often do not correspond to the real values. A great risk to purchase a low-quality product exists when ordering goods on various online sites.
You can protect yourself a little from acquiring such devices if you look at the reviews of real customers who have already tested the bank after purchase.
The purchase of products from well-known manufacturers will avoid the risk of buying low-quality devices. The maximum deviations of the capacitance value in such devices do not exceed 10%. In addition, branded products are covered by a long-term warranty, which will allow you to return money or get another product if there is a defect.
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