What is the Capacity?

Looking at USB Power Banks I noticed that a 20,000mAh power bank stated in the Items Specifics section as having a capacity of 8000 mAh. However, the Product Specification indicates a Capacity of 20000mAh.
Is this normal? Does a 20,000 mAh power bank only have a capacity of 8,000 mAh?

Jerry

Just an assumption:
20000mah is the “hook you in advertising”
8000mah is probably the real capacity

There are a lot of fake mah claims our there, not saying this one is but seems dubious to me :expressionless:

That is what I think also.

Given the size comparison to the iphone 6 I think it would be a stretch to get 6000 out of it.
20000? Ridiculous.

I once bought a power bank this size it had about 1000mah battery in it lol. I told Fasttech and they said bad luck!

All power banks have conversion losses.
mAh can’t be compared unless the voltage is the same.

Please look at the fifth picture of this review: Xiaomi 20,000mAh Powerbank review & capacity test
20,000 mAh @ 3.6v
12,700 mAh @ 5.1v
That’s about 63% difference when just looking at the mAh.

20,000 mAh @ 3.6v = 72,000 mWh
12,700 mAh @ 5.1v = 64,770 mWh
That’s about 90% when looking at the mWh. -> Very good

Assuming the same voltage thing for your power bank.
20,000 mAh @ 3.6v = 72,000 mWh
8,000 mAh @ 5.1v = 40,800 mWh
That’s about 57% -> Very bad

Perhaps a typo? Not uncommon on Chinese sites. 8000 -> 18000
20,000 mAh @ 3.6v = 72,000 mWh
18,000 mAh @ 5.1v = 91,800 mWh -> That would be magic, so no typo :slight_smile:

$11 for 8000 mAh isn’t that bad but I would never buy it because I have to carry that weight around all the time.

But as flydive noted the picture doesn’t match the size. I think they just messed up big time.

Why don’t you buy the empty kit and use your own 18650’s that way you know the true capacity :smiley:

Disclaimer, I have not used or even heard about this one, it is just an example :stuck_out_tongue:

Cheers David

I have a couple of kits, but not enough batteries for any more. When the kits and batteries are purchased you can buy the “ready made” banks cheaper.

I really don’t need any power banks, but just playing to see what is available.

Thanks, Jerry