How much an output amperage should be to achieve a fast charging?

zillah · 26 Jul 2021 at 18:06

Dear folk

To my understanding, (please correct my confusion)

Output voltage most of the time is 5 DCV

To achieve fast charging fast charging amperage should be bigger or equal to 2 DCA

I did a test using 2 USB power meters and 2 different lightening cables and 2 wall adapters (10W, means 2A as voltage always 5) to test it on iPhoneX which can take up to 2A

As per the attached snapshots output current was less than 1 ?? Means not fast charging ?

https://imgur.com/a/kisBgoW

Thx

KompuKare · 26 Jul 2021 at 19:46

While the original USB spec was 5V, the various quick charging implementations use way more than 5V.
Qualcomm use up to 20V or more, a bit like USB PD (Power Delivery) does:
https://en.wikipedia.org/wiki/Quick_Charge#Versions
If they didn't up the voltage, the cables would have to very thick.

zillah · 26 Jul 2021 at 23:47

Thx for that

Semple · 26 Jul 2021 at 23:51

Are you using the original charger and cable? Or some third party one?

Also how charged is your battery? Don't know about the new quick charge specs, but it used to be aimed at charging your phone from low to high quickly. If it's already on 80% eg then this might not happen.