I have a power supply for my Huawei Mate 20 that can charge with a maximum of 22 watts.
The output shows on the power supply: 5V = 2A or 4.5V = 5A or 5V = 4.5A (it is not an equal sign but a long line at the top and three short lines at the bottom)
What does this mean and how do I know which devices I can charge with the power supply?
P = U * I
P is the power in watts and you is the voltage. I is the current.
with the last values you get 22.5W
Such power supplies are usually smart enough to automatically find the right voltage and current
That means the power supply has different output modes. Between the power supply and the device, it is virtually automatically negotiated which output mode is active, i.e. How much voltage is supplied and what maximum current can be supplied.
The power supply can deliver a voltage of 5 V in an output mode, and deliver a maximum current of 2 A at this voltage.
The power supply can deliver a voltage of 4.5 V in an output mode, and deliver a maximum current of 5 A at this voltage.
The power supply can deliver a voltage of 5 V in an output mode and deliver a maximum current of 4.5 A at this voltage.
As a rule, a USB power supply unit can be used to charge all devices that can be charged via USB. Because almost all corresponding devices can be charged with a voltage of around 5 V, which is usual for USB.
Ok I understood that but how do I know now what I can charge with the power supply?
Older cell phones or tablets charge much more slowly. Can I still use this power adapter?
Yes, a clever power supply automatically regulates the current down.
Yes, you can. The power with which charging is usually automatically negotiated between the power adapter and the cell phone or tablet.
The dash with the short dashes means that the output gives the output of the power supply a DC voltage. You also need this if you want to charge a battery. It would not cope with the AC voltage from the socket. The voltage must therefore be transformed so that the voltage is not 230V but less, rectified, smoothed and stabilized so that your device can work with it. Your power supply does that and a few more things for you.
In the end you will get what you have written here, probably adjustable, right?
Now you look at your battery, which you want to charge and you make yourself smart, how high the final charge voltage is and with what current the battery charges. Your power supply should be able to provide the power that the device demands or otherwise have overload protection e.g. In the form of a charging current limit.
if your power supply has this, you can hardly care about the current. If the charging current is less than the current with which your battery can charge, it means nothing more than that it takes longer until it is fully charged. If your power supply can supply a larger current than the device needs, it will simply no longer flow. This does not apply to charging batteries per se, this only applies if the battery has been connected to a charging electronics. Then Dan pulls exactly the electricity it needs and no longer. Oversizing does not hurt the charging electronics as long as the applied voltage fits.
