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Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Wed Mar 23, 2011 12:08 am
by yoke
I know I need an 8.2K ohm resistor
but... I have found them in various watts.. ( 1/8 up thru 2 W...)
what watt rating should I be looking for for I definitely need to do this mod.
I have the transmitter and the deal extreme batteries have been shipped :)

thanks in advance.

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Wed Mar 23, 2011 7:55 am
by Ampair
The wattage for this application are uncritical. 1/8 or 1/4 w are best, purely from a size and weight standpoint. Heavy components need to be tied down to resist handling stress

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Tue May 03, 2011 12:37 am
by Kaldek
Hey folks, I just did my battery mod today using the TrustFire 2400mAh batteries. It's, uh, a very tight fit; my battery cover is bulging in the middle visibly!

The only thing I did different was wrap my batteries in a bit of electrical tape so that they didn't split apart (i.e. if the glue failed). Thoughts?

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Wed May 04, 2011 1:49 am
by kaptain_zero
I used Trustfire 2400mAh cells here as well, only I just used some hotmelt to stick them together and I have no bulging issues but it's a snug fit. I suspect the electrical tape is the issue in your case. Perhaps forgo the tape and just get some heat shrink from Radical RC. They carry the thin stuff meant for going over Lipo packs.

Regards

Christian

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Fri May 20, 2011 6:31 am
by chrispaiva
Can I use the main charging connector to charge this trustfire ?

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Mon May 23, 2011 1:46 am
by Kozmyk
I wimped out on the LiPo conversion and bought one of these instead.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=14076
8.8V is a reasonable alarm level for this LiFePo so that's one less mod hanging off the board when I come to try reflashing the firmware with ER9X or Gruvin9X.

Shopping around for the 18650 cells DID get me a good deal for rejuvenating my old laptop battery pack though so thanks Bruce ;)

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Mon May 23, 2011 3:06 am
by kaptain_zero
I switched to custom firmware (ER9X) so I was able to set my low battery alarm to a suitable setting for my trustfire pack. I did order one of the LiFePo4 packs mentioned, and it does fit the radio, but again... it's higher voltage than my 2x18650 pack and so the circuitry has to *waste* the extra voltage by shedding heat and heat is the sworn enemy of electronics, so I decided to stick with the diy pack. Fortunately a close friend was looking for a pack for his JR and so he took it off my hands.

As for using the main power connector, I don't, so I cannot answer your question..... I would not go ahead without doing some checking first, if I were you. I just yank the pack out and plug it into my lipo charger.

Regards

Christian

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Mon May 23, 2011 3:24 am
by Kozmyk
chrispaiva wrote:Can I use the main charging connector to charge this trustfire ?

There's a diode for reverse polarity protection in the +ve line between the charge socket and the battery connector.
You'd need to remove that diode and replace with a link to use a lipo charger through the charge port.
The diode would confuse the monitoring circuit of the lipo charger. It only conducts in one direction and drops the voltage by about 0.6V when it does conduct in the forward bias.
Whether the 9X circuitry will tolerate being subject to the fluctuations of the charger output is another thing to consider.
I don't know the answer to that one.

So the safe answer is: Charge from outside the Tx until you get confirmation that it would be safe to charge inside.
At least the 18650s will charge quickly instead of overnight.

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Sat Jul 02, 2011 12:44 pm
by Sugna
Hi
I am thinking of doing the $8 battery mod, and I have 2 questions :?:
1. Which battery do you guy recommend? (brand, mAh etc.)
2. Should I put a balance tap on the battery?

Thanks in advance :)

Re: Turnigy 9x transmitter li-ion battery conversion

PostPosted: Wed Jul 06, 2011 9:33 am
by Sugna
Hi all
is everyone using the 8.2k ohms resistor as listed or what looks the be a 820 ohms resistor shown in the photo?
Image