UBS Type-C input readings are pretty different from direct input readings


I have an Apple charger that’s rated at 12W, and reliable tests with my qualMeter X at 2.4 Amps, when the qualMeter is plugged directly into it.

However, when I need to the same charger using a cable into either the USB Type-AF input, or the USB Type-C input, I get 3.1 Amps.

Is this a qualMeter error between the two types of input?

Also, I find that most USB-C to USB-C cables do not show any current at all, when going from say, a Google Pixel 3 Amp charger, into the qualMeter’s USB Type-C input. I know they are good charging cables… they charge the phone!

Any suggestions would be greatly appreciated. Otherwise, love the unit!


Hi George,

Thanks for posting here.

I am not 100% sure what you wanted to do. It seems you wanted to test your chargers by using the cable testing ports.

qualMeter only can test chargers via the USB-AM input port. All the other USB female ports are for cable testing only. You cannot input power by connecting those ports directly to the chargers’ output. By doing this, you have high chance to damage qualMeter.:sweat: Our manual has marked this in Bold.

Hope this answers your question.



Yes, thank you. That answers it. I’m just not very good with manuals. :slight_smile:


hahaha, yea, ture, me too sometimes.:grinning:

My previous landlady once told me men never read manuals.:joy::joy: