hey guys, I recently purchased a 9X & I'm planning to upgrade it to a 3S Li-Po ( the ones HK stocks specifically for transmtters).
I just want to know how many are using lipo and are charging it to full voltage i.e 12.6V ??
I'm getting mixed responses from other sources.
AFAIK the regulators used are the 7805 equivalents, and they can easily handle 12V inputs easily. Also went through the schematics, seems no problem with 12.6V I/P.
but, the again some reported issues.
i would be glad if anybody could help..

I would recommend using LiFe instead like in below link.

HobbyKing LiFe TX Battery

Better use NiMH Cells.
Best use duracell or similar alkaline battery.

The power requirement of Tx is not much like flight pack. It is something like Digital Camers (from power requirement point of view). So, use whatever suit you best.

Just remember, your DigiCam have auto power off option, but your Tx have no similar option. So, if you forget to switch off, your cell may damage permanently if its lithium based one. So, decision is yours and the money too.

Here C capacity is not important, but the mAH is important and weight to carry.

And for the technical quiry,

The sensing and controlling block works on 5 volt and does not differ for 13 or even 15 volt.
But the Power RF Amplifier block works on 12Volt supply (Module) and this affects the range.
Have you measured ever total voltage of 8Nos AA New alkaline or dry cell ? It's near 13.2 Volt (Open Circuit voltage i. e. E.M.F.).

kalyan sir no response for my topic

Vineet, Check PM Please.

I'm using Rhino 2620 Lipo with my turnigy 9x, no problem till now and you need to keep an eye on the voltage as you should not drain the power. I have not tested the transmitting range yet with lipo

@spitfire: but, wouldn't that give me significantly lower flying time between charges considering a lipo can be used..

@kalyanprodhan: yes sir, i checked the voltage and it was around 13.1 (but it does drop significantly once connected to the Tx) ,but, a fully charged lipo is 12.6. thats why I dunno why theres so much uncertainity. lipos do have much lower internal resistance, but, i guess the Tx is just like a digicam like you said, so should'nt be an issue..
personally i abandoned alkaline batteries since I was a kid.. no punch at all.. my plane hasn't yet taken off and the batteries are beginning to die just in experimentation... so looking for alternatives

@Purush: thanks, that was really reassuring.. do you fully charge it to 12.6 ??

After a full charge with IMAX B3 charger I get 11.8V..

I have been using the Tx1450 turnigy lipos on my futaba 6eax with two diodes 1004 in between the terminals so as to limit the output voltage with out any issues from the last 6 months and on a single charge they give a backup for nearly 30 to 40 days.

@sorav: well Futaba is a very renowned brand and they must have good electronic parts & designs. so no surprise that they can tolerate a bit of overvoltage . the qestion is about the cheap(only pricewise, otherwise they seem pretty good) radios like Turnigy/Ergule and the similar..
9x users.. please comment...

Sir as far as the tolerance level is concerned,turnigy i also a very good brand and people have been using the same upto their limits.Any ways the only reason to use the diodes was to limit the o/p voltage so that it may not harm the tx.

@sorav: hmm... diodes are good but limit the lower operating threshold.. 30-40 days is pretty good btw..

what about the discharge rate(c rating of battery) guys , will that not harm tx, ..

Discharge rate for Tx Lipo should be low as low current is required for Tx compared to motors.
Using high discharge batteries most likely result in burning up Tx. So one should not use regular Lipo for Tx.

I use this battery with Tx. Once it is charged it last for around month for me including weekend flying and regular sim practice.

discharge rate is not gonna hurt... it's just the max amps the battery can deliver.

the 2.4 ghz module has a 7805  inside, so the fully charged 3s lipo is not going to bother tx in any way. i am using 3s lipo with my 9x.

Me too use the Rhino 2620 on my 9x Tx and have the same experience like Spitfire has. Only thing is to be careful about the polarity while you connect as it comes with a different plug and make sure your Tx is turned Off once you are done with it. Good luck.

hmm.. looks like I can safely go ahead.. thanks. samlikespad, spitfire &vishal ( yeah I knew that, thats why the confusion, if it was a 7805 why did some radios burn up) !
@vishal: i just said they were low cost, should have chosen words carefully, kinda made a wrong impression.

reas, most of the burning were due to the polarity reversing. To be honest with you, I burnt one of them for the same reason. It was late night during a plane build, I had this new Rhino battery, plugged in wrong, and burnt. Ordered another one, but I fixed mine recently by changing couple of components. Right now am using lipo on both with out any problem. Anyhow, I usually charge them to 12.4 (equal to 8 AA batteries) to be on the safe side though LM7805 should be able to handle 12.6.

Hello sir,
I have used my turnigy 9x with 3s lipo without any problem whatsoever. Just make sure to order a lipo which fits the compartment(take a margin of atleat 2-3mm)

Santosh.

which lipo , can you provide link

http://www.hobbyking.com/hobbyking/store/__16529__Turnigy_2650mAh_3S_1C_LLF_Tx_Pack_Futaba_JR_.html

http://www.hobbyking.com/hobbyking/store/__17955__HobbyKing_1500mAH_LiFe_3S_9_9v_Transmitter_pack_.html


both of them fits in the compartment.

Those two are currently on BK. I use this one and so far happy with it. http://www.hobbyking.com/hobbyking/store/__7346__Rhino_2620mAh_3S_11_1v_Low_Discharge_Transmitter_Lipoly_Pack.html

i've already ordered the tgy 2650mAh batteries (on jan 12, typical HK).. waiting to get them..
i'll post my experience soon after i've tested it..