Using a Lipo in Futaba Transmitter

[gevaho]

hi everybody,

Are there people here who are using tx lipo in their futaba radio's?

my question is that the radio works on 9.6 V and the Lipo's are 3s 11.1 V isn't that bad for the radio?

You can get very cheap TX lipos on ebay and it keeps your radio working for weeks without charging .

Nimh batterys have also the memory effect you need to charge and decharge them often to keep them in good condition so a lipo would be an good upgrade.

So feedback om this from you guy's is very welcome.

[steffgiguere]

I've been running a Lipo in my 10C for over one year now without any problems. Charge fly, around 40 flights, then remove, charge, reinstall in TX and fly around 40 flights...etc. I usually charge when it drops to 11.1.

[BarracudaHockey]

Had one in my 9C for years. Only possible issue is if you leave the transmitter on the low voltage cut off is way to low to save a lipo

[gevaho]

thanks guys.

that takes away my worries about the higher voltage of the lipo. What kind of voltage reading you get when putting in the fully charged lipo?

Cool to see that steffgiguere has 40 flights on it and still have 11,1 V in the pack.

[riccardoc]

Originally Posted by steffgiguere

I've been running a Lipo in my 10C for over one year now without any problems. Charge fly, around 40 flights, then remove, charge, reinstall in TX and fly around 40 flights...etc. I usually charge when it drops to 11.1.

Where did you get the LiPo Pack for your 10C?

[steffgiguere]

I got it from my LHS.
When I put a freshly charged battery it reads 12.4V.

[leonmike]

I use it on my 7C. Charge it to 12.6V but shows only 12.4 V on the Tx. I try not to let it drop below 11.0V, not good for Lipos. See pic on the one i am using. If you need to know where i bought it i can PM you.

https://www.helifreak.com/showthread.php?t=174228

It even comes with the standard Futaba connector which you plug straight on.

[digipaq]

I am using 1 in my 10C. If you are worried about the high voltage which may harm your tx, you can always add diodes to lower the voltage. I use 3 voltage which will lower the voltage to 10.4v at fully charged. Recharge the lipo when it drops to 9v shown on LCD (actual voltage will be 11.2v). Even if you forget to turn off the tx, and the low voltage alarm will go off at 8.4v, still you will have 10.6v in your lipo, not too low to kill your lipo yet.

[gmhelo]

Originally Posted by digipaq

I am using 1 in my 10C. If you are worried about the high voltage which may harm your tx, you can always add diodes to lower the voltage. I use 3 voltage which will lower the voltage to 10.4v at fully charged. Recharge the lipo when it drops to 9v shown on LCD (actual voltage will be 11.2v). Even if you forget to turn off the tx, and the low voltage alarm will go off at 8.4v, still you will have 10.6v in your lipo, not too low to kill your lipo yet.

Exactly what I did, putting diodes in line has the added bonus that if you have a brain fart and plug the nicad charger into the tx no voltage will be applied to the lipo.

Win-win I say!

[gevaho]

could anyone post the specs of the diodes and the way you fitted it? Would be very hellpfull with a pic if possible. I read other posts of people who dont use the diodes and are still fine. But better safe then sorry not?

[gmhelo]

Originally Posted by gevaho

could anyone post the specs of the diodes and the way you fitted it? Would be very hellpfull with a pic if possible. I read other posts of people who dont use the diodes and are still fine. But better safe then sorry not?

Never participated in this thread but...

http://www.rcgroups.com/forums/showt...=lipo+diode+tx

I used three diodes in series to drop the voltage 3 x .74V = 2.22V. My transmitter (Futaba 9C Super) reads 10.4V when lipo is fully charged and the alarm alarms at 8.5V which is 10.7V on lipo 3.56V per cell - still a little low but not a battery killer.

If you run without diodes the alarm will only sound if you allow the voltage to drop to 2.83V per cell - certain death to any lipo.

I am more than happy with my mod.

As I said earlier, win-win!

[gevaho]

He mate thanks very much this what needed. gonna try that too.

And indeed win-win situation save the tx and the lipo!!

again thanks.

[DustinB]

I looked at going with a lipo but with a 2500mAH NiMH I never run it down on a full day, plus I always charge everything the night before. Plug the Tx in before I go to sleep and grab it before I leave. The NiMH batteries do not develop a memory, they have a problem hold their charge for extended periods of time when not in use, hence charging the night before. NiCd batteries are the ones that have a memory problem.

Based on what I do NiMH work just fine for me and run at the proper voltage. Keep in mind higher voltage means faster discharge so you would need say a 3000mAH lipo to get the same capacity as a 2500 mAH 9.6v NiMH. (Just a guess...) My method is simple and I usually always plan the night before.

It really depends on what you plan to do when you fly. A lipo will charge in an hour safely. I could fly my NiMH battery for weeks as well, it's all about capacity. I still charge before every flying day, crashes are expensive...

[gevaho]

I think that is a way to. I have a 1700mah tx pack and a batteryholder for 8 nicads as a spare, . that leaves me with not enough lipo's for the heli to use up al the battery 's for the tx.