How to check the battery?

Question

Batteries

I bought an external charger on Ali, at first there were a lot of good reviews, but now there are a lot of reviews that the charger is not original - left power sources are used inside.
The body is glued to the conscience, I don’t want to break it in vain.
How to check the compliance of the charging parameters with the technical parameters?
What to measure and on what basis?
In the presence of a multimeter, socket, charging, android phone.

Answer 1

well, measure the output parameters that are indicated in the documentation or on the box - that's all

Answer 2

It is rather laborious to measure the capacity of the battery yourself; special devices are used for this.

Answer 3

Battery capacity is measured in amps per hour. If you can provide a constant discharge current, subject to a decreasing voltage, then you can measure the capacitance. There are special devices that charge and discharge the battery with a calibrated current, thereby measuring its capacity. You can't do this with a simple multimeter. If you have doubts after buying a charger, it will not be superfluous to compare the performance of the battery after charging with a standard charger and after charging with a newly purchased one. VERY part of the Chinese-made additional devices do not provide proper charging parameters. The result for you will be the same - a short lifetime.
In general, you should always remember that the battery is a consumable item. Are you changing the battery in your car? And in all other places they are the same consumables and change in the same way! The average life expectancy of a battery anywhere is a couple of years. After that, there is no point in measuring something, you just need to go buy a new one. However, when you buy a new one, there is still a danger of buying a low-quality one... Be careful!!!