Battery capacity
The higher the battery capacity, the more energy the power bank is able to accumulate and then transfer when charging to gadgets connected to it. But it should be borne in mind that not all of the accumulated energy goes specifically to charging – part of it is spent on service functions and inevitable losses in the process of transmission. So in the specifications, the real capacity of the power bank is also often specified. If there is no data on real capacity, then when calculating it is worth proceeding from the fact that it is usually somewhere 1.6 times lower than the nominal one. For example, for a model with a nominal capacity of 10,000 mAh, the actual value will be approximately 6300 mAh.
As for the specific values of the nominal capacity, then in models with the lowest performance it is
5000 – 7000 mAh and even
less ; such power banks are suitable as a backup source of energy for 1 – 2 smartphone charging with a not very capacious battery or other similar gadget. The
10,000 mAh solutions are the most popular nowadays – in many cases, this option provides the best price-capacity ratio. The
20,000 mAh and
30,000 mAh options are also very common. But even a capacity of
40,000 mAh or
more, thanks to the development of modern
...technology, is quite common.Power bank charge power
The power in watts at which the power bank is charged under normal conditions.
The higher the charging power, the less time it takes to charge (given the same battery capacity). For example,
fast charging of a power bank typically means a charging power of 30W or more. However, this parameter does not directly affect compatibility with charging devices: modern portable batteries can work with chargers of both higher and lower power. In the first case, the battery controller will automatically limit the charging current, while in the second case, charging will simply take more time.
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.
