How to test USB charger with direct to Micro USB cable

#1

I have a Raspberry Pi board that has strict power requirements. The charger comes with a pre-wired cable that ends directly with a Micro USB male plug.

How can I test this charger with qualMeter X ? It seems the only micro USB input is for cable testing, not charger testing. Supplying power directly to the micro USB input on the qualMeter X just indicates a “Cable Test”, and “Worst” LED.

This is the charger: https://www.amazon.com/Vilros-Raspberry-Clear-Power-Supply/dp/B01D92SSX6

Please advise if testing this charger is possible.

#2

@evnglst

You’ll need a Micro USB Female to USB Type A Female adapter to allow qualMeter X to test it.

You can not plug your charger direct into the MicroUSB port on qualMeter! This could damage the meter. :scream:

Instead, you could have a normal type third party cell-phone 5V USB charger with greater than 2.5A output (test with qualMeter to make sure the output capability) to use with your Raspberry Pi board.

#3

On Fri, Jul 27, 2018 at 12:06 PM, Jack noreply@intelliplus.cn wrote:

You’ll need a Micro USB Female to USB Type A Female adapter to allow qualMeter X to test it.

Yes, I figured that out, found one, and tested the charger. The
qualMeter showed the charger to be 3.1 amps.

You can not plug your charger direct into the MicroUSB port on qualMeter! This could damage the meter.

Yes, I wasn’t going to plug it directly into the MicroUSB port on the
qualMeter.

Thanks for your reply,
George

#4

Thanks for your reply George!

We are considering to provide adapters to improve qualMeter’s testing compatibility. But we are not sure about how many users would be needing them.

#5

Hi Jack, lovin’ the QMeter… it helps me in lots of ways.

Another question: when testing output from a battery, some batteries act just like a USB charger source, and I get an accurate reading in amps. But when checking other batteries, the lights will start progressing up, but then reach, say 2.2 amps output, and then everything just shuts off on the qualMeter X.

Does this mean the battery is protecting itself, and cutting off current?

Thanks again for the great product,
George

#6

Also, when testing a certain USB hub, sometimes the qualMeter will only show Worst light. Nothing else.

I asume this means the USB hub is not supplying any power at all? :slight_smile:

#7

Hi George,

You are right. The behavior on power sources are vary when they are over loaded in different conditions. Their output power are not exact the same, there are always slightly different. So sometimes, when the power drawing is right on its limit, they could shut-down right away, and the qualMeter will lost power to operate. However, sometimes the qualMeter will remember the last value it’s not been shut down (if it has time to record) on the same plug. If you re-plug qualMeter twice, it will stop at the last good reading and will not go further to be shut down.

And yes, in general, most of USB HUBs without extra power input don’t have capability to deliver more than 500mA power.

Enjoy metering! :sunglasses:

Jack

#8

Thanks, Jack!

#9

Hi…In my experience it’s rarely the USB cable either, more likely to be a duff charger or not using the right one for that phone.How to tell which one straight away? - well you can try the same cable on a different, known working device and if that don’t work either, bad cable.