What are the battery cells in a power bank?

By wangterry 0 comments

Essentially, a power bank is just a smart battery.

You can take it everywhere to recharge your phones.


If you are not a geek of engineer, you may probably not take a power bank apart to see what’s the battery inside.


But as a science fan in your soul, may sometimes disturb you,

Scratch you to make it out.


Let me do it for you, buddy!


There are lots kinds of batteries in power banks, but the most common batteries are two.

Which are:

  • 18650 li-ion battery
  • li-polymer battery


As you can see on the picture,


What’s the difference between them?


Theoretically,there are quite a lot differences between them,

But as a consumer, as a wise buddy, as a focus point in parties.

You only need to know two things as below:


Size is the most important difference:


18650 means the battery wideth must be 18mm, and height must be 65mm, and shape must be round.(remember these numbers, you can talk to your friends casually about it.)

So when some 18650 batteries put into a power bank, the whole size must be big and heavy.


As a time of light and smart nowadays, this kind of batteries are not so welcomed.

So why it is still popular now?


That’s the only answer.


OK, let’s move eyes to li-polymer battery, which on the right side of the picture.

They are soft rolls,

So we can make it whatever shape as we need.

If you want a ultra-thin or some creative shape power bank, you need to buy this kind.


I know your next question, buddy.

Does it much more expensive than 18650 batteries?


Consider of the whole power banks are not so expensive, you really should not ask this question, buddy!



I’m joking, I know your next question muse be:


Which one is safer?


Let’s say it this way:


Some really bad 18650 batteries can explode and the worst li-polymer battery won’t.


Now you get the answer.


Search “Charmast li-polymer power bank”, or just send me a email,



You may get one as a gift.

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