XPowerBank

Beware of some dishonest cheap Powerbanks that claimed to have high mAh !!!

One of the key issue of mobile phones, particularly smartphones, is that they are power hungry causing their battery doesn't last long. As a result, mobile power bank comes into the market as portable external power source to supplement the internal battery of the mobile phone or mobile device.

The major problem or hazard of these batteries is that, they will overheat when charged for long time. There is an overcharge prevention IC on its circuit board to cut off the charging when the battery is fully charged. If the IC is malfunctioned, the battery might caught fire or explode when overcharged.

Nowadays, you can find a lot of power banks claimed to have charge capacity as high as 12000mAh, 18000mAh, 20000mAh, or even higher, selling at the Internet stores. If they are unbranded and selling at a very cheap price, you need to be alerted before placing your order.

Most of the powerbanks in the market normally used 18650 model batteries in their product. The size of the battery in used is 18.25x65mm, and their manufacturing part number is normally in the form of XXX18650-XX. However, the quality of the batteries used is totally different.

Branded made-in-Japan (eg. Sanyo, Panasonic) one normally has capacity of at least 3100mAh, and comes with 1 year warranty. They have higher price too and won't be chosen to make the cheap power bank selling in the Internet stores.

Branded made-in-Korea (eg. Samsung) one is quite reliable too. Part number could be ICR18650-30A, ICR18650-28A, ICR18650-26F, ICR18650-26D, ICR18650-24E, ICR18650-24F, ICE18650-22F, etc. 30F means capacity is 3000mAh, 22F means capacity is 2200mAh, and so on.

Samsung OEM made-in-China battery has 4 grades. The highest A01 grade normally reserved for Samsung own use, while A02, A03 and A04 are made available for customers. Part number could be ICR18650-20, ICR18650-22, ICR18650-24, ICR18650-26, etc. If a power bank claimed to use Samsung batteries, the batteries inside are probably the A02~A04 type.

Certain unbranded made-in-china battery were found to have only 1600-1800mAh but also put in the 18650 code and claimed to have 3000mAh. The cheap power banks probably are using this kind of Li-Ion battery.

For the power bank with 12000mAh capacity above, its capacity is calculated like this:

3000mAh x 4 = 12000mAh

However, if the real capacity of the batteries inside is only 2200mAh, you can only get 2200mAh x 4 = 8800mAh.

For the power bank with 18000mAh capacity above, its capacity is calculated like this:

3000mAh x 6 = 18000mAh

However, if the real capacity of the batteries inside is only 2200mAh, you can only get 2200mAh x 6 = 13200mAh.

Beside the possible short-change in real capacity, since the size of the Li-Ion batteries are the same, some dishonest power bank might even use recycled batteries!

Lets just look at one of the example in the picture below:


This is a newly purchased powerbank which has been opened for inspection. Look closely at the terminals and you could see different colours which also means that all these batteries are unlikely to be produced in the same batch. That might be even sign of recycled batteries!