Very important update on this issue about the mosfets going bad on this battery testing machine I have been working on this issue some more recently and have more information about it
The issue with not being able to battery test BMS boards with this device has bothered me ever since it happened to me but I want an answer to the question to WHY

you can not test BMS protection boards
So a couple of days ago while I was at work I was brainstorming ( not having a brain fart ) about this issue and decided to run this test on my battery testing machine to get some answers how I ran this test is as follows
The the parameters are as follows
Set the battery testing machine to CC 4.20 volts @ 1.00 amps
But here is the twist of this test
Hook up the voltage leads to a 18650 battery cell
Hook up the output power leads to two 28 volt incandescent light bulbs in series
Then hit start on the testing machine what results do you think you will get
The the incandescent light bulbs light up at 24 volts and the screen shows the following
Battery voltage is 3.994 volts
Battery current is 840 milliamperes
Conclusion is that this battery testing machine only controls the current but to make sure that my hunch is correct I ran the following test several times with different amperage as follows
Set to as follows
100 milliamperes light bulbs did not light but the amp screen shows 100 milliamperes
200 milliamperes light bulbs did not light but the amp screen shows 200 milliamperes
500 milliamperes light bulbs are lighting dimly and the amp screen shows 500 milliamperes
Final conclusion is that this battery testing machine only adjusts the current output
But I have a very important question to ask how is this battery testing machine controller controlling the buck converter circuit I can not find any information about how to control this buck converter in current mode only
The data sheet only has how to use it in voltage mode or in cv cc modes together but not only the current mode
I did read some where that you use the feedback pin to control the current mode but no one has elaborated about how it functions in detail and better yet with a microcontroller how you would control it