Battery capacity
Battery capacity in watt-hour. These units of measurement are less popular than MilliAmp hour, but are more physically correct: they accurately describe the amount of energy accumulated by the battery. Thanks to this, in terms of capacity in Wh, it is possible to compare batteries with different rated voltages (while for mAh this is not allowed — additional calculations must be carried out using special formulas). At the same time, Wh can be converted to mAh without much difficulty if the battery voltage is known (for power banks this is in most cases 3.7 V): to do this, the capacity in Wh must be divided by the voltage and multiplied by 1000.
USB type C
The total number of
USB type C ports for charging connected gadgets. By 2023, they have become very popular. However, power banks are equipped mainly with
one output port of the corresponding format.
Models with 2 USB type C outputs have not yet gained such popularity.
USB A
The total number of
USB-A ports for charging connected gadgets. This type is gradually being replaced by USB type C, however, most models still use USB-A as the main output. This is also indicated by the number of corresponding ports. Classic are
2 USB-A outputs. However, there are also compact
models for 1 output, and more impressive ones with
3 and
4 USB-A(even more).
Max. power (per 1 port)
The maximum power that the power bank, theoretically, is capable of delivering to one rechargeable device. Usually, this power is achieved under the condition that no other device is connected to the battery (although exceptions to this rule are possible). And if you have ports with different charging currents or support multiple fast charging technologies, this information is given for the most powerful output or technology.
For modern power banks, a power of
10 watts or less is considered quite low; among other things, it usually means that the device does not support fast charging. Nevertheless, such devices are inexpensive and often turn out to be quite sufficient for simple tasks; Therefore, there are many models with similar specs on the market. The power of
12 – 15 W is also relatively small,
18 W can be called the average level,
20 – 25 W and
30 – 50 W is already considered an advanced level and in some solutions this parameter may
exceed 60 W.
In general, higher power output has a positive effect on charging speed, but in fact there are a number of nuances associated with this parameter. Firstly, not only the power bank, but also the gadget being charged should support the appropriate power — otherwise the speed of the process will be limited
...by the specs of the gadget. Secondly, in order to use the full capabilities of the power bank, it may be necessary for it to be compatible with certain fast charging technologies (see "Fast Charging").USB type С
USB type C is a popular type of USB connector characterized by its small size, reversible design, and fairly advanced (in theory) capabilities. If there are several connectors of this type, the first one is considered to be capable of delivering more power.
It is characterized by the rated power supplied by the power bank when a load is connected to the first or only
USB type C output and the current strength. The speed of the charging process directly depends on the power. It is traditionally calculated by multiplying the current by the voltage; However, the standard voltage for USB power is 5 V, so current is considered to be the main indicator of power.
The magnitude of the charging current directly determines the power supplied to the device being charged - and, accordingly, the maximum speed of the process (in practice, it may be lower if the device being charged has strict restrictions on the charge current). Power is also determined by the supply voltage (the number of watts is calculated by multiplying amperes by volts); While the standard USB output voltage is 5V, many fast charging technologies (see below) use higher voltages. Therefore, in the notes to this paragraph, the maximum power on the USB type C connector is also indicated.
As for specific values, the most popular option for USB type C outputs in modern power banks is
3 A. There are also other values - both sma
...ller ( 2.4 A, 2.1 A and 2 A) and larger ones - but noticeably less frequently.USB A
A standard
USB A port is characterized by the rated power supplied by the power bank when a load is connected to the first or only USB A output and the current strength. If there are several connectors of this type, the first one is considered to be capable of delivering more power.
The speed of the charging process directly depends on this indicator. Power is traditionally calculated by multiplying current by voltage; However, the standard voltage for USB power is 5 V, so current is considered to be the main indicator of power.
The charging power and, accordingly, the speed of the process depend on the current strength. Nowadays, on USB ports, a current of
2 A or
2.1 A is considered basic and quite modest,
2.4 A and
2.5 A are average,
3 A and
more are noticeably above average, and certain fast charging technologies allow you to achieve values of
4 A. 4.5 A and
5 A. However, it is worth considering that to operate at high current, such an opportunity must be provided not only in the power bank, but also in the gadget being charged. So when purchasing a model, it doesn’t hurt to check whether the devices being charged suppo
...rt high charge currents.
It is also worth noting two nuances associated with the presence of multiple USB charging ports. Firstly, they may differ in the current they produce. This allows you to select the optimal connector for each device: for example, to quickly charge a tablet with a capacious battery, it is desirable to have a higher current, and a device with a low charging current can be connected to a “weaker” port, so as not to create unnecessary load on the battery and controller. The second caveat is that if all USB connectors are used simultaneously, the current supplied by each of these connectors may be lower than the maximum; in other words, not all power banks allow you to simultaneously use USB ports at the maximum possible power. You can understand whether such a possibility exists by looking at the charge power (see below); if the charge power is not indicated, you should refer to detailed documentation from the manufacturer.Power bank charging inputs
The type of input used to charge the power bank's own battery. Simply put, this paragraph indicates which connector on the cable you need to charge the power bank. At the same time, some models provide several inputs for charging at once, which simplifies the search for a cable. Also note that for models with a built-in power bank charging connector (see below), the type of this connector is specified separately.
Most often in modern power banks there are standard connectors
microUSB,
USB type C and/or
Apple Lightning. A lot of accessories are produced for such connectors — cables, network and car chargers, adapters, etc.; so there is usually no difficulty in finding a source of energy. Less common are models with
DC input, they are usually equipped with their own power supply (or at least a cable under such a connector). Here is a more detailed description of the different types of inputs:
— microUSB. A smaller version of the USB connector, still very popular in portable tech, despite the active spread of the more advanced USB type C. It has relatively modest capabilities — in particular, it does not allow the implementation of some advanced fast charging technologies. On the other hand, it is very easy to find a source of energy for such a connector: both modern and many of the frankly outdated cables and chargers are
...suitable for it.
— USB type C. A miniature type of USB connector, positioned, among other things, as the successor to microUSB. The most noticeable improvement is the reversible design, which allows you not to worry about which side of the plug is inserted into the connector. However, in the case of power banks, this is not the only or even the main advantage: USB type C has more extensive capabilities, allows more powerful currents and use a wider range of fast charging technologies (and Power Delivery was originally created specifically for this connector). Note that in some models the same connector of this type can be used both as an input for charging the battery and as an output for charging external devices — moreover, with automatic switching between these modes.
— Apple Lightning. Initially, this connector is designed for portable gadgets made by Apple. However, in the case of power banks, it can also be found in third-party devices: the idea is that the presence of Lightning allows you to charge an external battery using a cable from an iPhone or iPad and eliminates the need to look for a separate wire. For a number of reasons, this charging input is rarely used as the only one, more often it is provided in addition to microUSB or USB type C (see above).
— DC input. DC is a standard covering several types of connectors at once. Their common feature is a signature round shape, but the diameter, rated voltage and power can be different. In this sense, such connectors are not as convenient as USB type C, Lightning and other generally accepted standards — with a DC socket, it is best to use a native power supply (usually it comes bundled right away), and finding a third-party power source can be a problem. On the other hand, inputs of this type have practically no power limitations, it is easier to achieve high power supply with them than with the connectors described above. Therefore, DC inputs are used mainly in high-capacity power banks, where charging through a "weaker" interface would take an unreasonably long time. However, such models can also be equipped with standard microUSB or USB type C connectors "just in case".Power bank charge power
Nominal power supported by the power bank when charging its own battery through the appropriate interface. See "Battery Charging Inputs" for details.
Wireless charger
The power supplied by the power bank in
wireless charging mode.
In accordance with the name, with such charging, energy is transferred to the device being charged literally via the air. However the range of such a transmission is only a few centimeters, so the gadget usually has to be placed directly on the power bank. However, it's still much easier and more convenient than fussing with wires, and the connectors don't wear out.
As for the power, the higher it is, the faster the external device can be charged. Initially, wireless technologies did not differ in power, but nowadays, even for power banks, the minimum is actually 5 W — this is comparable to the power of a modest, but far from the weakest USB port. There are also models with 10 W — this is comparable to the highest power that can be achieved at the USB output in a standard format, without the use of special fast charging technologies.
Of course, in order to use all the possibilities of wireless charging, the charging gadget must also support the appropriate power.
