With the increasing usage of our mobile devices (such as Smartphone, tablet, MP3, handheld game consoles), having that amount of battery life in the device itself would not be enough to operate the whole day or even half a day for some users.

Therefore in this tech-savvy environment which we are living in, portable power banks seem to be getting more popular and commonly used among these Smartphone using people.

Before diving into a store to get a power bank, do you really understand about these power banks and how they function, or how to even choose a power bank which is suitable for your mobile devices and lifestyle?

This article will come in handy for anyone who wishes to get their hands on a power bank to give their mobile devices the extra fuel for a day of heavy usage.

1) What is a Power Bank?

A power bank serves as an ‘extra battery’ pack or a portable external charger for your mobile devices such as Smartphone and tablets.

2) Where are these Power Banks manufactured in?

Majority of these power banks sold in the market are actually manufactured in China but its battery cell or printed circuit board (PCB) modules may come from other countries.

3) How do I correctly charge a Power Bank?

The most advisable way to charge up a power bank would be via a USB adapter to a wall plug. However, do note the power input of the power bank before charging it. Overcharging or overheating may occur if a power bank with a lower power input is being charged with a higher output USB adapter. E.g., 2.0A power output USB adapter to power bank, 1.0A power input. You may still charge a power bank via a computer USB port, but it would take a significantly longer time to fully charge up a power bank.

4) How long do I need to fully charge a Power Bank?

Depending on the total capacity the power bank is holding, larger capacity power banks would require longer charging time. As mentioned above, different charging methods would result in different charging times. Charging from a computer/laptop USB would result in an extended charging time of at least twice of what it would normally require.

5) Why do I need longer time occasionally to charge the same Power bank?

Charging time may differ even with the same charging method is due to external factors like the environment, temperature, power current, etc.

6) What is mAh?

The full term for ‘mAh’ means Milliampere Hour, used for measuring the capacity of the power banks.

7) Would a 12000mAh Power Bank be able to fully charge up a 1500mAh capacity Smartphone for 8 times?

This is a common misconception by most people about power banks.

For a rough gauge of the total number of full charges, try out the following calculation method:

Power Bank’s total capacity × Conversion Rate × Smartphone’s battery health

÷ Smartphone’s total capacity

= Total number of full charges

EXAMPLE: 12000 × 0.8 × 0.75 ÷ 1500 = 4.8 full charges (0.5-1 times plus minus)

8) What is Conversation Rate?

Conversation rate is the remaining percentage of the battery after power lost through heat or PCB operation, but not through charging.

9) What is Smartphone’s battery health?

It is basically the recharging health of your Smartphone. As the Smartphone is being used over time, the battery will deteriorate, reducing in the battery storage capacity. That is why new phones can last much longer as compared to one that is used over a period of time.

This effect happens differently on different model of Smartphone as one’s battery may drain faster than the other.

10) What is PCB?

The full term for ‘PCB’ means Printed Circuit Board, used for controlling all the operation flow within the power bank. A good quality PCB allows the power bank to be charged up more efficiently and has better durability on the battery life.

11) What is the difference between an 18650 cell and a Li-Polymer in a Power Bank?

18650 cell

  • Size and dimension are fixed
  • Produces more heat
  • Cheaper cost
  • Higher self-discharge rate
  • Durability drops faster


  • Size and dimensions are flexible
  • Produces lesser or no heat
  • Higher cost
  • Lower self-discharge rate
  • Durability maintains better

12) What are the common capacities in 18650 cell power bank available in the market?

1) 1200mAh – 2600mAh uses 1pc
2) 2500mAh – 4400mAh uses 2pcs
3) 3750mAh – 6600mAh uses 3pcs
4) 5200mAh – 8800mAh uses 4pcs
5) 6500mAh – 11000mAh uses 5pcs
6) 7800mAh – 13200mAh uses 6pcs
7) (no info) uses 7pcs
8) 10400mAh –14400mAh uses 8pcs

13) Is there any Power Bank that uses higher than 2200mAh per 18650 cell?

Yes, but uncommon due to the expensive cost to manufacture.

14) What is the different between Branded Power Bank and Generic Power Bank?

Branded power banks mostly come in its true capacity, where as Generic power banks have their capacity marked up to a higher value than it truly has.

This is why branded power banks do not have their power capacity as high as 30,000mAh to 50,000mAh. A good quality 12,000mAh to 13,000mAh branded power bank’s charging performance would be that of or better than a 30,000mAh to 50,000mAh generic power bank sold in a market.

Power banks sold on a global commerce platform (eBay, Amazon, etc), mostly have their power capacity marked up higher than it actually has and they are cheaper. Reliable power banks (Samsung, Sony, RedMonster, Anker, Valore, etc.) usually come with a higher price tag and also a warranty of at least one year or longer.

15) Is it true that Branded Power Bank would not explode as compared to a Generic Power Bank?

Any gadget or electronic that has to do with batteries, would likely to have chance of it exploding regardless of a branded or a generic power bank. However the chances of both branded and generic power banks to explode would be rather unlikely, unless the batteries used are the lowest quality 18650 cell. On the other hand, power banks that use a Li-Polymer is much safer as compared to an 18650 cell and also able to fit into high-temperature environment more easily.