ToolkitRC M7 MultiCharger Fan Coilwhine Fix

[ceut]

Hello !
I have bought a new multi charger tool: a ToolkitRC M7.
I have already a iMaxB6Mini (genuine), and a ISDT Q6 Nano from a friend to compare.
 
First warning: it is completly not calibrated out of the box ! 
I was having an error of about -0,18V ! So it will overcharge batteries 

So with the hidden menu and my Keysight: I have done the calibration and now it is good

Second problem: big coilwhine but only when the Fan is active (starts spinning at >45°C ).
To check that: I have stopped it with a little toothpick and the noise is super audible 
I have checked on the user manual: between 45-53°C the Fan is in slow mode (big coil whine), and >53°C Fan is in full speed mode and no coil whine.

So I have just teared it down and put my Siglent on the 2 pins of the 5V fan, here is what I have on picture 1:
An horrible PWM signal at 1kHz => that's why it is really annoying 

Then, I have tried many capacitor value, and the best I have found is 47µF: the fan is faster and the coil whine is a less annoying.


==> I don't know is some of you have this charger, and have tried to fix the fan coil whine with another way ? It will be great to post your mods 

Thank you 


Edit: I have opened a ticket on ToolkitRC support, and have uploaded a video on Youtube here:

[ceut]

Reply to myself 

The ToolkitRC support has replied me.
They thank me for my "wonderful explanation" ! 😃
Also my ticket has been transfered to their engineer for either increase PWM frequency, or set the Fan at full speed.

I'm really to see that , they seem to be as great as Ruideng support ! (I have made another video with my RD6006P they have fixed after I have sent them the overshoot problem) .

So now, have to wait for a new Firmware update...

[fatsafen14]

Hi.  I'm torn between toolkitrc m7 and isdt q6 nano for a charger too.  I'm afraid of m7 because of problems such as calibration etc.  but my heart is with him.  What are your general thoughts on the two?

[ceut]

Hi.  I'm torn between toolkitrc m7 and isdt q6 nano for a charger too.  I'm afraid of m7 because of problems such as calibration etc.  but my heart is with him.  What are your general thoughts on the two?

Hello,
For the time being, I don't recommand the M7 because I have posted my ticket on september, they told me that they will fix the problem with fw update, but I have no news from them since... 

The Q6 Nano is really good, a friend has lent one to me and I have used a lot without any problem, and no coilwhine noise from it. Only some missing feature and a smaller screen.

So my advice is: if you are not in hurry, wait for the fw fix from ToolkitRC and go for the M7, or buy a Q6 Nano if you are in hurry 

Both need calibration, but the M7 is really bad with factory value (dangerous too  ), whereas the Q6 is ok.


For a comparison with a great brand Ruideng (RD Official Store) from Aliexpress, I have uploaded them a bug from a PSU I have bought from them (a RD6006P): they send me the fix after about 2 month (hardware+software fix).
So now they are on my top value manufacturer 
I have posted all here:
https://www.eevblog.com/forum/testgear/ruideng-riden-rd6006-dc-power-supply/msg4354561/#msg4354561

[fatsafen14]

Thank you so much for answer. Have a nice days:)