RC Model Reviews

Hi,

As has been widely discussed in these forums, the standard 8xAA battery holder is not a preferred option for use with the Turnigy 9x TX.

I'm planning on using a JST connector to replace the 3 pin connector that the battery holder uses and was after some guideance as to how to best connect this to the TX.

The options as i see it are:
1. Simply take the red/black cable that by default is connected to the side of the Tx case (bayonet socket), unsolder it from the bayonet socket and assuming that it's wired up correctly (polarity) then i'd just put a JST connector on the end of this and poke it back through into the battery compartment.

2. If anyone was to suggest a reason as to why this cable should be left attached to the TX case, then i'd run a new set of wire from the backside of the PCB as shown in the pics below.

For either option i wanted to check if anyone could confirm the correct polarity of the cables coming out to the bayonet socket on the side of the Tx case. I've included the pics of inside the Tx case where i'm working. My multimeter suggests the polarities are as shown in the picture but i was interested if anyone could confirm the expected pin voltages.

Thanks
Peter

What you want to do is leave the negative wire in place and re-solder the red wire onto the other side of the diode. This is so that you're able to charge a lipo properly (the diode prevents this).

It also means that when you turn on the remote, the charger is disconnected from the battery!

what we did was just build a small adapter cable from jst to the 2s balance plug that the radio has

Peter,

Futher to what I said in my PM, you will not be able to power the radio through that external connector's wires. When the switch of the radio is turned on, these two wires are disconnected from the radio as to stop you from trying to charge the battery while the radio is on (even though that's not what YOU are wanting to do)

Cheers
Chris

Hi Chris,

Ahhh - minor light bulb moment - of course - the ole protection circuitry.

Ok - so that means the points on the PCB that i'd indicated as likely places to solder on my proposed JST male connector won't work either - it'll be subject to the same protection.

I'll have to call upon the collective knowledge of the forum at this point -

When people have added in new wires to bypass using the default 3pin connector in the Tx battery comparment, where have you soldered the +/- leads onto the PCB? Doesn't matter what sort of connector you use. (i'm using a JST connector, but i know others have used servo leads etc).

Thanks
Peter

I added a JST plug on my 9x just by looking to see where the + and - leads from the original battery pack soldered to the board and I soldering the JST wires to those lands. I'm using the 2 cell $8 battery mod from this web site and the JST connector is a real added benefit. I don't see where there is any circuit protection built into this connection as I am using the very same connection points as the original battery pack. I remove the battery pack from the Tx to charge it and it's been working fine like this for many months now.

That's how I did it as well...

Sorry if I confused anyone. The bypassing of the diode is essential if you want to use the EXTERNAL port to charge the INTERNAL Tx battery. I diode in series with the battery will stop the charger working if it's a lipo. I read the question wrong :O