Cheap buck boost power supply goes into protection mode when I turn it on

Thread Starter

zirconx

Joined Mar 10, 2010
154
Hi, I got this cheap buck boost power supply from Amazon today. Model number is ZK-4KX. I want to use it to charge a battery at a max of 1 amp. I set the current limit to one amp and the voltage to 13v. My battery is around 12.5v currently.

From a cold boot the power supply works fine (I demonstrate that at the end of the video). But if I toggle the output off and back on again, the power supply delivers as much current as the load will draw and then goes into over power protection mode (OPP on the screen). This is defective, right? Just making sure that I'm not doing something wrong.

Here's a 1 minute video of me demonstrating the issue.

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ronsimpson

Joined Oct 7, 2019
2,067
I set the current limit to one amp and the voltage to 13v. My battery is around 12.5v currently.
I take a power supply. With no load I set the voltage to 13V. Next I set the max current to 1A. Next I connect to a battery now at 12.5A. The voltage will drop to 12.5 or a little more. The voltage will slowly increase to 13V as the battery charges. At 13V the current will slowly drop back to a small number.
The supply is set to be in a box. Never over 13V and never over 1A. These are the walls of the box.

You cannot push the battery from 12.5 to 13 in a short time.
 
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