Are all PowerBanks the same?We have had firsthand experience with Chinese companies trying to sell us Powerbanks with bad quality recycled batteries. Fortunately we know how to test batteries true capacity and output endurance. Batteries come in various grades and it's important to know what quality you are purchasing. The second part of a powerbank that is critical is the IC chip. Below is an excerpt from an article translated from Chinese. It was posted by a Taiwanese called on his Facebook page. The photos are taken from his original article.
Beware of dishonest cheap power bank claimed to have high mAh capacityOne of the key issues 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.
While most of the modern mobile devices nowadays are using Li-Polymer battery () as their power source, a lot of mobile power banks are using the cylindrical or prismatic Li-Ion battery ().
The major problem or hazard of Li-Ion battery and Li-Polymer battery is that, they can 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 could caught fire or explode when overcharged.
Another disadvantage of Li-Ion battery is their lifespan will greatly reduced if they are operating in high temperature of 45°C and above. Li-Polymer battery, on the other hand, has higher endurance to high temperature, and can still operate over 4 hours in 85°C without much problem.
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.
The shorter power bank in the picture above consists of 4 Li-Ion 18650 batteries, while the longer one consists of 6 Li-Ion 18650 batteries. The size of the cylindrical Li-Ion battery in used is 18.25x65mm, and their manufacturing part number is normally in the form of XXX18650-XX.
The quality of Li-Ion battery differs.
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 Li-Ion 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!
The picture above is said to be taken from a newly purchased cheap power bank, opened up for inspection. Note that the colour of the 6 Li-Ion batteries are all different, which is very unlikely if they are manufactured from the same batch.
Also note that the soldering point is rusted and shows sign of multiple re-soldering. There is also leftover glue on the surface. Worse still, what if the cheap dishonest power bank does not have a properly functioning overcharge / over-discharge circuit? And even more ridiculous case, you probably get only a single Li-Ion battery with 2 bags of sand.
The bottom result is you need exercise caution when purchasing Powerbanks from China, especially when the product is unbranded and the price is cheap.
Beware of fake 2,400 mAh PowerBank device - Gadgeter 12 Apr 2013 Fake Power Bank, Power Bank - www.gizmochina.com
If you’re planning to buy a portable battery charger device or also called as “power bank” yuhave to check and re-check, while a Taiwanesse user found his stuff is a fake with only wad of sand in his power bank.
Perhaps because of frequent traveling and not always be near a power outlet, the man reportedly bought a power bank with capacity of 24,000 mAh made a company from Shenzhen, China.
Brief look there’s nothing wrong with the white power bank. There is a power button below the indicator lights and a USB port. Capacity is suspicious information that sounds too unbelievable.
Sure enough, once opened, turned on the power in the bank found two plastic bags filled with sand, which is likely deliberately placed there by anyone who makes it to give the sensation of “heavy” convincing.
Those power bank can still be used to charge gadgets because it provides a power-dusty old cell. Original capacity is unknown, but most likely not reach 24,000 mAh, this is the fake products, so you have be careful.