How to select a right power bank product?

High light: Due to difficulty of identifying false capacity of power bank (to identify, look into another article for tip), selection criteria will never be higher capacity with lower price, instead, right capacity with reasonable price should be the best. This article show you how to determine right capacity of power bank based on various application scenarios.


Before you go to a shop buying a power bank you need to ask yourself these questions.

1.       What are or how many mobile devices you want them to be served by targeted power bank?

2.       How heavy usually are you using your mobile devices? Is a daily charging good enough?

3.       When and where do you want to use the power bank product?


At the end, selecting a power bank product is about selecting its charging capability meeting your demands provided you know clearly what your charging demands are. There are many demand scenarios such as

1.     You and your loved one will go a short holiday carrying two mobile phones with 2100mAh (Galaxy SIII) and 2600mAh (Galaxy Note) power demand, you don’t want to carry two chargers and worry about different power socket standard from Singapore or find no power point. Suggestion: a 7500mAh power bank with dual outputs will do the job well.

2.     You are a heavy user and your smart phone battery often exhausted before getting in home/office for next charge. Suggestion: a battery case for iPhone 4/4S user. or for iPhone 5 user, or for Samsung Galaxy S3 user.

3.    You are an outdoor sales / agent carrying both smart phone and iPad meeting many clients a day. You don’t want to miss any business opportunity due to running out of either devices’ battery. Suggestion: a 13000mAh power bank with dual outputs should be right selection..

4.     You are a student and preparing for a coming camping, you may expect a power bank with a real torch function to keep your phone live and have fun at night.

5.    You love outdoor sports, mountaineering, field exploring where you hardly find electricity and only solar energy is available, you might consider a Solar Power Bank.

So on and so forth.

You may ask: How these suggestions are derived?

Very simple, you just need to lump all your power demands estimation and divide by an energy transferring factor to get minimum required power bank capacity. See this forum post to know how to select an energy transferring factor.

You may ask: How do I estimate each of my device's power demand?

For Samsung mobile devices user, you can open up the device's back cover and find its battery capacity easily.

For Apple products user, please look at this forum post to find relevant information.

For example, your mobile devices are a iPhone 5 and a iPad mini, you often carry them going a weekend holiday, you want both devices to be fully charged at least one fold. your total required power bank capacity will be (1440 + 4490 ) / 0.7 = 8471 mAh.  thus a 8800 mAh capacity power bank will be a minimum choice.

If you are so tired of math, simply choose a 10000mAh power bank with dual outputs will usually cater for most of your demand scenarios.

Other consideration--Output port and current capability, most of power bank product provide either single port or dual ports output, either 1A or 1A+2A current capability. What you need to know is a minimum required charging current when your mobile device battery exhausted to below 5%. It is 0.5A for most smart phone, 1A for most iPad, 1.2A for iPad3/4.  However, 1A current will charge smart phone faster, 2A current will do so for iPad.


Author: Product Manager from

31th May 2013