Hi, All

I want to use HobbyKing 1500mAH LiFe 3S 9.9v Transmitter pack
http://www.hobbyking.com/hobbyking/store/__17955__hobbyking_1500mah_life_3s_9_9v_transmitter_pack_.html
 with FlySky TH 9x, In order to connect it to Tx, do I need to anything like trim AA battery connector and solder it to JR/Spektrum plug of battery etc. or Is it fine if I use battery futaba plug(black) to battery plug into transmitter by keeping red wire into middle and black on left side of red wire? I searched on web and it seems we can use futaba style plug to FlySky TH 9X.

Reference : http://aircraft-modeling.com/content/radio-controlled-models/lipo-batteries-for-turnigy-9x-and-turnigy-9xr/
 

Nothing is necessary, you can use the black plug in either ways, [ie.,  black to the left or right, keeping the red/positive in the middle of the three pin male connector in the tx at all times].

I got myself a rcb wolfpack lipo 3s for the same tx and it works well. Good pricing for the life there, but pricing will go higher with the addl. shipping costs.

Thanks tantranga !!
One more thing how can i charge HK 1500mah life with turnigy accucell 6 charger, i can see accucell has only XT60 female connector and battery has futaba,Jr,spektrum conector. Do i need to trim of JR connector and sold XT 60 male connector to battery to charge it?

Try not to alter the connectors at the battery terminals. Get an equivalent sockets/plugs at the charger end to make a bridge [say JR/Futaba type male plugs] in your existing terminal type at the charging end and swiftly charge it without much hassle, after all the charge rate is just 2C and the connector can handle the charging power.

Soldering a XT60 male connector will probably become a challenge as it will be too fat to fit in the battery compartment and might damage the life battery/compartment in the process. The wolfpack lipo is little smaller than the this hk life battery yet, it is quite a challenge to pack the battery in the compartment while retaining its all original connectors.

PS: I am not an endorsing agent, but a humble request to purchase from local vendors/hobby shops to support them. Get the battery from RCB or any other LHS, the one I have got is sufficient to run maybe weeks/month without recharging it. RCB Link here.

Are you talking about something like this? or I have to create my own? Will this fit to Turnigy accucell 6 charger
http://www.technohobbies.com/multi-charging-cable-300mm.html

Yes, that should work or yo can make your own by getting the needed connectors and wires.