Ove vrednosti sam izmerio posle oko 3 metra usb kabla. Inace teorija me ne zanima mnogo, samo praksa bato.
Tako da ne znam gde si to procitao da >>> USB 2.0 obezbeđuje 0.5 A , USB 3.0 do 1A..
A sto se tice power bank-a naravno da se preporucuje sto kraći kabal.
Samo ti iz kucista pokazi ove vrednosti a ne sa nekog produznog kabla gde ne vidim source.
A do tada , prouci sledece gradivo:
Okay, now the numbers. A regular USB 1.0 or 2.0 socket has four pins, and a USB cable has four wires. The inside pins carry data (D+ and D-), and the outside pins provide a 5-volt power supply. USB 3.0 ports add an additional row of five pins, so USB 3.0-compatible cables have nine wires. In terms of actual current (milliamps or mA), there are three kinds of USB port dictated by the current specs: a standard downstream port, a charging downstream port, and a dedicated charging port. The first two can be found on your computer (and should be labeled as such), and the third kind applies to “dumb” wall chargers.
In the USB 1.0 and 2.0 specs, a standard downstream port is capable of delivering up to 500mA (0.5A); with USB 3.0, it moves up to 900mA (0.9A). The charging downstream and dedicated charging ports provide up to 1,500mA (1.5A).
USB 3.1 bumps throughput to 10Gbps in what’s called SuperSpeed+ mode, bringing it roughly equivalent with first-generation Thunderbolt. It also supports power draw of 1.5A and 3A over the 5V bus.
https://www.extremetech.com/computi...ks-or-how-to-avoid-blowing-up-your-smartphone
Inace cisto da znas , kada nakacis potrosaca onda se meri amperaza i voltaza a nikako bez potrosaca ... pogotovo ne sa kineskim multimetrom od 2 dolara.
ili kupis od 3 dolara usb tester koji radi posao odlicno.