Charging port.

[Rad]

Hi guys, this probably has been asked to death but can't find much info.
I want to use the charging port of the Th9xb. I am using a couple of li ions 18650 with no balance plug, so I think I could start using that port instead of forcing the back tray of the radio, because the battery is a super tight fit.

Is there something I have to consider? What is the name of the plug, and where goes the positive and negative?
Using 9xtreme board.

Thanks!

[Kilrah]

If I remember well the 9x has a diode in the charge path so you'd need to remove that or it would mess with the voltage measurement. And it's not great to charge without balancing/protecting the individual cells.

[Rad]

If I remember well the 9x has a diode in the charge path so you'd need to remove that or it would mess with the voltage measurement. And it's not great to charge without balancing/protecting the individual cells.

Hi, it is a pack with a built in chip, so it works good with no balance plug.

Let me know if you remind where is that diode that needs to be removed.

[MikeB]

The diode is on the back board, near where the wires from the charge socket connect.

Mike

[Rad]

The diode is on the back board, near where the wires from the charge socket connect.

Mike

Great news is in the easy side of the radio! I did not want to touch the zillion things I have installed.

Ok, I have been googling a while, and the connector is 5.5mm x 2.1mm. Ill get one and I will wire it to my smart charger.
Once I have the parts here I will open the radio and remove that diode. I only have to remove it and replace with a bit of wire, right? or is there something else you recommend me?

[MikeB]

The diode is on the "other" side of the board, so to replace it will require the board to be removed. You could, however, just solder a wire across it without removing the board.

Mike

[Rad]

The diode is on the "other" side of the board, so to replace it will require the board to be removed. You could, however, just solder a wire across it without removing the board.

Mike

Thanks! No probs at all removing that board.
The problem would be the other side of the radio. There are so many things there now, being the encoder the worst part of it that at this point I'd think twice before touching it.
https://radindustries.wordpress.com/202 ... /my-radio/


Ill be ordering the jack today. Thanks as always!

[Rad]

Hey, small update here.

I have the jack almost in the way, once this chinese new year ends it will be shipped. I took a look at the radio and I will remove that diode as you pointed me. Due to mistakes happen I think it would be great to keep some sort of reverse polarity protection there. Can I install a mosfet or something similar that does not cause voltage drop?

Thanks!

[bob195558]

Have you seen this, Reverse Current Protection Mod for 9xtreme
https://openrcforums.com/forum/viewtopi ... 126&t=7745

[Rad]

Have you seen this, Reverse Current Protection Mod for 9xtreme
https://openrcforums.com/forum/viewtopi ... 126&t=7745

Yes sir, and I did it long time ago, but I dont know if that mod is only for plugging the battery the wrong way, or if also works for the charging port.

[Rad]

Has anybody more info about it?

[jhsa]

A while ago, I have designed a completely new switch board for my 9x radios, that had reverse polarity protection on both power and charge circuits I think.. It would also keep the radio ON if the switch suddenly failed and made some bad connection.
I need to search my old files.. actually, all my radios have this installed
I might also have posted it here on the forum somewhere.

João

[jhsa]

Found the forum thread..

https://openrcforums.com/forum/viewtopi ... =95&t=8210

João

[Rad]

Found the forum thread..

https://openrcforums.com/forum/viewtopi ... =95&t=8210

João

My godness, after reading your thread, this is me:

https://www.youtube.com/watch?v=9CS7j5I6aOc

Way too much info and diagrams that I am afraid I cannot understand, lol.
Your idea might be an overkill for me. Would it be possible to just install something for reversing protection in the side of the radio where the original diode is?

[MikeB]

Go to the first post if this thread: https://openrcforums.com/forum/viewtopi ... it=9xtreme.
Download the file 9xtreme_schematic.pdf.
At the top of the diagram you will see Q3, this is a P-Channel MOSFET (AO3407A SOT23 package). This is wired as a reverse polarity protection device. All you need to do is to wire a suitable P-Channel MOSFET across the existing protection diode, DRAINsource to the charger input, SOURCEdrain to the other side of the diode and gate to ground. You may wish to find a MOSFET in a wired package (e.g. TO92) rather than a surface mount device. Just find one that meets the same specification as the AO3407A.

Mike

[Rad]

Go to the first post if this thread: https://openrcforums.com/forum/viewtopi ... it=9xtreme.
Download the file 9xtreme_schematic.pdf.
At the top of the diagram you will see Q3, this is a P-Channel MOSFET (AO3407A SOT23 package). This is wired as a reverse polarity protection device. All you need to do is to wire a suitable P-Channel MOSFET across the existing protection diode, source to the charger input, drain to the other side of the diode and gate to ground. You may wish to find a MOSFET in a wired package (e.g. TO92) rather than a surface mount device. Just find one that meets the same specification as the AO3407A.

Mike

Thanks Mike, that seems much more doable for me. I took a look at the T092 in aliexpress and I found it has a very similar look to a "BK15 BS170" thing I bought in the past if I remember correctly, for the haptic in the radio. Would it work? Or do I just get the this T092?
https://www.aliexpress.com/item/3290717 ... hweb201603_

[MikeB]

NO! The 2N7000 is a N-Channel MOSFET, you need a P-Channel MOSFET.
Tricky to find one in a TO92 package that handles a couple of amps, you may need to go for a larger package, or perhaps a surface mount D-PAK package device. You need a device that handles 2A (or more), has a VGS of at least 10V (your battery voltage, and a VDS of 20V (or more).

Mike

[Rad]

Oh, thanks for pointing my mistake!

I have been taking a long look at it on the web, and well, basically I don't even really know how to look for it, lol. So unless some of you know the name of that mostfet in the t092 version, I think I will order the SMD mosfet you said, which if I am not mistaken, is this one: https://www.aliexpress.com/item/3281964 ... xatOI&mp=1

[jhsa]

All you need to do is to wire a suitable P-Channel MOSFET across the existing protection diode, source to the charger input, drain to the other side of the diode and gate to ground. You may wish to find a MOSFET in a wired package (e.g. TO92) rather than a surface mount device. Just find one that meets the same specification as the AO3407A.

Mike

Mike, I think that for reverse polarity protection, the Drain will connect to the Charger Input, and the Source to the radio power switch.. Something like this?

JD3LH.jpg (24.84 KiB) Viewed 106 times

João

[MikeB]

Oops yes, I've edited my post above.
Rad: That would be fine, you may prefer to get the AOD403, shown at the right of that page. This is in a much larger package so will be easier to fit.

Mike

[Rad]

Thanks for the diagram, Joao, and thanks for the part, Mike. That should be a very easy and well worth add to my radio.
I am ordering the parts right now.
It seems there is always something else I can add in the radio, which is great!