Charge cycles
The number of charge-discharge cycles that the battery can withstand without significant loss of performance.
During operation, batteries wear out, and because of this, their specs (primarily capacity) noticeably deteriorate. Battery life is usually measured in charge-discharge cycles. The features of counting cycles are described in detail in special sources, but here we note that not always models with the same claimed resource turn out to be equally durable in fact. The fact is that different manufacturers may understand “significant loss of performance” differently: for example, one brand can indicate a resource up to a 20% decrease in capacity, the second — up to a 60% decrease. Therefore, when choosing, it makes sense to focus not only on pure numbers, but also on other sources — test results, reviews, etc.
Also note that battery life can be noticeably reduced if the operating conditions are violated — for example, in case of overheating or excessive cold.
Power bank charge current via USB
Nominal charge current supported by the power bank when charging its own battery via microUSB, USB type C, or Lightning (see "Battery charging inputs").
This is the maximum and, in fact, the recommended power bank charge current. If the amperes supplied by the power source exceed this value, the charge current will still be limited by the built-in controller to avoid overloading. And using a charger with a lower output current, in turn, will lead to an increase in charging time.
Data on the charge current via USB (Lightning) is especially important due to the fact that modern power banks are usually not equipped with their own chargers for these inputs, and energy sources must be separate. On the other hand, if a high charging speed is not critical for you, you can ignore this parameter: any USB connector is suitable as a power source for the corresponding power bank inputs.
Bundled cables (adapters)
Types of cables and/or adapters for charging external devices included in the power bank set.
The type of such cables is indicated by the plug used to connect to the gadget being charged; connection with the power bank itself is usually carried out through a standard USB A or USB type C output. We emphasize that in this case, we are talking about detachable cables/adapters; types of built-in charging cables are specified separately (if any — see below).
In general, this parameter allows you to evaluate the possibilities of a power bank available out of the box, without purchasing additional accessories. As for specific interfaces, most often external batteries nowadays are equipped with
microUSB,
USB type C and/or
Lightning cables/adapters; more specific connectors are extremely rare. Here are the features of the most popular options:
— microUSB. A connector that is extremely common in modern portable gadgets. It is inferior to the newer USB type-C in terms of convenience and several performance specs, but still has not lost popularity.
— USB type C. A relatively new standard for miniature USB connectors, used for charging both portable equipment and larger devices — in particular, some ultra-compact laptops. Physically, it differs from microUSB in a slightly larger size and a two-sided design that allows you to connect the plug b
...oth ways. In terms of performance, USB type C is notable for better compatibility with fast charging technologies (see above): more fast charging technologies can be used with it, and Power Delivery was created based on this connector. At the same time, the presence of a USB type C cable does not mean support for fast charging.
— Lightning. Standard original connector for Apple gadgets; other manufacturers do not have such a port.
Note that if several types of bundled cables/adapters are claimed in the specs, the specific format of such accessories may be different. For example, "microUSB plus USB type C" could mean two separate cables, one cable with two plugs, a cable with one plug plus an adapter to another, etc.Body material
The main material used in the the body of a power bank.
In addition to traditional
plastic, nowadays, external batteries are produced in cases made of more advanced and/or "prestigious" materials. Of these materials,
aluminium is the most widely used; also you can find products made of
steel, zinc,
leather,
fabric and even
wood. Here are the main features of each option:
— Plastic. The most popular material for the bodies of modern power banks. Plastic, on the one hand, is inexpensive, on the other hand, it is quite durable and has a small weight, on the third hand, it makes it easy to create cases of any shape and colour, which is especially important for devices with an unusual design. In terms of strength and reliability, ordinary plastic is somewhat inferior to metals; however, in everyday use, this difference is not critical — except that scratches on such a case will appear faster. And for extreme conditions, cases can be produced from special impact-resistant plastic.
— Aluminium. Aluminium alloy housings are highly durable and lightweight; in addition, they look stylish, and the appearance is retained for a long time due to scratch resistance. The main disadvantage of aluminium is that it is more expensive than plastic.
...— Steel. Steel is notable for its high durability and reliability; according to these indicators, it surpasses even aluminium, not to mention plastic. On the other hand, this material has a significant weight, and therefore is used much less frequently.
— Leather. Solid body (plastic or metal) with additional leather cover. Such a coating does not affect the functionality and plays a purely aesthetic role: it gives the device a stylish and eye-catching appearance, allowing you to turn the power bank into a stylish accessory. However, note that in the design of such products (especially inexpensive ones), artificial leather (leatherette) is often used, which is noticeably inferior to natural leather in reliability, durability, and sometimes in appearance. Genuine leather, on the other hand, significantly affects the price — its cost can be more than half of the total price of the entire power bank.
— Fabric. A hard case (usually plastic) with a fabric outer covering. Such a coating not only gives the device a rather original appearance, but also gives some practical advantages: the fabric is pleasant to the touch and does not slip in the hand, which reduces the risk of dropping the power bank. On the other hand, various contaminants are poorly removed from such a surface, it has no fundamental advantages over plastic or metal, but it costs much more. Therefore, fabric cases are not very popular.
— Wood. Another design material used mainly for its original appearance than practical advantages. Nevertheless, wood is not inferior to plastic; and some users also consider the natural origin of this material to be an important advantage. On the other hand, wooden cases do not have noticeable advantages over plastic ones, and they cost much more.
— Zinc. Zinc alloys are similar in most properties to the aluminium alloys described above, however, for a number of reasons (in particular, due to the greater complexity in production), they are used extremely rarely.
