How to choose a better USB cable with UM25C and HD35

RD_tech · 2019-07-26T01:12:11.000Z

Hello everyone, good day.

Nice to see you again.

Last time I made a video to show you how to test the quality of the chargers, we can make a review, there are 2 ways to test the quality:

1.Use electric load to ******* the quick charge mode it supports, set the max voltage, increase the current slowly until it reaches the max value. Check if the voltage drop higher than 0.5V, if so, the quality is not so good.

2.Leave the charger working under full power situation, check the temperature change,if the the temperature increase a lot, the quality is bad.

But as we all know, when we charge our phones, we use two things: charger and USB cables. So the charging speed depends on the quality of charger and USB cables.

Today, I will test several USB cables to show you how to choose a better USB cables.

Here are the USB cables need to test, mark them as A, B, C.

First, we check the hardness of the cable. Usually, soft USB cables have good quality and hard USB cables’ quality is not so good. Here is the result:

Cable C< Cable A< Cable B (soft to hard)

Then we check the charging current when we use the same phone, the remaining battery should be around 50%, so that it can show you the accurate current.

Though the appearance of A and B are similar, the charging result differs, we can see the result in pictures below:

Here is the result:

Cable A: 4.927V 1.1965A

Cable B: 5.029V 0.4183A

Cable C: 4.836V 1.9332A

According to the data, we can know that when the charging speed is very slow, you cannot just say that I have a bad charger, maybe you have a bad cable!!!

then I want to do more test on these cables, I can measure the cable resistance about these cables, use the micro-USB port to test,you can see the port below:

here is the result

Testing Data:

Cable A: 0.312Ω

Cable B: 0.532Ω

Cable C: 0.084Ω

You can see the resistance of good quality cable are much smaller than bad cables, because when the manufacturer produce them, they use less material so that the cable is thinner than standard cable, and the resistance becomes higher.

There is one more reason if the charging current is small: if the USB-A port doesn’t fit well with the charger, the current will be small too.

You can test your USB-C cables in the same way because there are USB-C input port on UM25C .

you can use this port to test in this way:

All these test can be operated at home if you have a UM25C and HD35 electric load. If you have any advice or question, please leave comments below the article.

RD_tech · 2019-07-26T01:13:51.000Z

tool :
HD25/HD35: https://www.aliexpress.com/item/32917594486.html
UM25C: https://www.aliexpress.com/item/32855845265.html
YouTube link: How to choose a better USB cable with UM25C and HD35 - YouTube