Hardware Program to check power bank capacity?

[Bedel]

Well I've bought a power bank in orther to use it with my Android, Switch and PC, so I get one that presumibly has 30000mah. The question is I don't kinda trust in the store where I sold it, and I wanna make sure it's 30000mah and not only 15000.
Is there any program to check this?
Thanks in advance.

 

[nero99]

I think you would need to get some special electrical equipment to test that

 

[Bedel]

I think you would need to get some special electrical equipment to test that

Can't be done by software? Well I thought it could because a phone or a PC can, but being USB charge make things diferent, now that you say it.
If any one know something about it, I'll be watching.

 

[Minox]

You would want to draw a certain constant load from the power bank and then see how long it can provide said power while measuring how much is being drawn. That is not something you can do with computer USB ports as those are designed to provide power, not draw power.

 

[Originality]

Most people measure power bank capacity by seeing how many times it can charge a device with a known capacity battery.

For example, if an iPhone 6 has a 1810mAh battery, and a power bank charges it 3 full times and dies half way through the fourth charge, then you know the capacity is at least 1810x3.5= 6335mAh.

It's not an exact science because of the inefficiency of It all, but it gives you a good approximation.

 

[Bedel]

Most people measure power bank capacity by seeing how many times it can charge a device with a known capacity battery.

For example, if an iPhone 6 has a 1810mAh battery, and a power bank charges it 3 full times and dies half way through the fourth charge, then you know the capacity is at least 1810x3.5= 6335mAh.

It's not an exact science because of the inefficiency of It all, but it gives you a good approximation.

I'll try this out, thanks!