Walkera devo 12s and CTL01-D voltage issue!

This is what I sent to walkera but no reply at all!!

Hello,
I tried to contact you few times about this problem but still no any reply about it from you! I'm a little bit deluded about it!
I installed the CTL01-D telemetry module on my trex 800 and connected the 2x6s 5000 mAh batteries in series so the real voltage should be 46.2 volt but the telemetry module measures constantly 25.2 volt (on the devo 12s V1.5A/1.0., no matter what happen, if the real voltage is 50 volt or 46 the walkera telemetry measures always 25.2 volt!!
You can see my video about it on
I searched and I found the same problem encountered by this guy and others and is became famous!

After tests, I found that or the telemetry module doesn't measure more than 25.2 volts (in your instruction manual it is declared from 0.2V to 99.9V !!!!) or the devo 12s is not able to show more than 25.2 volts???

Please Help!!

Any idea??

You can find it in the internal manual when you buy it or:
www.himodel.com/radios/WALKERA_Two-way_2...tter_WK-CTL01-D.html
rcmodelaircraft.com.au/products/walkera-...dule-wk-ctl01-d.html
And it referred to the ctl01-d module not to the tx settings!!
Can you explain please what do you mean by "Devo protocol point of view" and the 8 bit counters??
Thank a lot

Yesterday I did what I thought should be a temporary solution till I find another one, I connected every battery separatly before the serial connector with the telemetry wires to the v1 and v2 ports on the telemetry module. when I connected the esc to the serial connector I fried the two wires (v1,v2) and I can't understand what happend?? any suggestions why or how to use the telemetry module with two 6s batteries connected in serial in a 12s configuration?
Thanks a lot

Ok ..... now I understand why just the black wire fried
Any suggestions ?

Can I connect the first battery normally to v1 and just the red wire to v2?
Could it work like this?

What you could do is to use resistors for reducing the voltage - use two resistors e.g. 1kOhm each (or more), place one behind the other, connect the battery - red to one end, black to the other. Connect the v1 OR v2: black to the black side, red to the middle. This way you halve the value and should get around 23.1V as you actaually have with 6S connected.
But you might add some error due to internal resistors int he CTL. So controls the values with a tool (voltage meter).

Thank you very much for your prompt response and the very useful advices. Assuming that the discharge amount should be  the same for two full batteries, so if I connect the v1 just to one of the 6s batteries before the serial connector and v2 to the servo and electronics 2s battery  it should be ok right? Thank you again

It's a little bit confusing: I start to answer the third time because when I think about it I throw the old away...

There are two different kinds of ESCs on the market: the simpler ones have internally a connection between the black line of their battery (in your case the serial connector) and the black line of the control line (coming from your rx). The better ESCs are electrically isolated, mostly with an opto-coupler).
So we have to differ. If the first is the case for yours, you have to connect the battery to the CTL (V1) which black wire is the one coming out as black wire from the serial connector. In the second case you could take any of the two 6S-packs.
I would recommend to use the black line of the serial connector for the black input of V1 and the conecction between the packs for the red input. If you are not sure from which battery you should get the red one test both - the one will show maximal values (25,4V), the other the real voltage.
This way you are on the safe side. If the ESC has no voltage separation and you connect the wrong black line to the CTL the weakest wire will burn because you shorten the black lines of the two packs - resulting in a connection of the black and red of one pack.


If your batteries have similar parameters (age, usage, capacity, C-rating) you can expect the voltage going down quite similar for both 6s-packs. If they differ, you can use the pack

A lot of thanks to torbe2012
I tried to connect v1 to the upper port of the serial connector from the battery side and it caused a short then as you suggested I tried to change and connect to the lower port and everything is ok now.
At least I can use the telemetry module instead of throwing it on the shelf!
Now I have v1 connected to one motor 6s battery and v2 to the electronics 2s battery as in the attached pictures and everything is ok.
Problem solved.
Thanks to everyone