RC India

Hi! needed some advice on picking the right Batt for my new AR6200 DSM2 Rx. It's going to be used on a .46 size High Winger.
I have a AR7000 and I'm using a Spektrum 4.8 NiCd 1100mAhr 4 cell pack.

@ Experts, for the benefit of all pls throw some light on how to go about choosing the right power pack for Rx and Txs, based on power ratings, consumption, dis-charge etc.. there are many factors to look into while choosing the heart of the Radio system.

thanks

Joe

Hey FlyJoe,

I also use AR6200 Rxs..  I always use them on 3s 11.1V 1350 mAh Lipo routed through a 5V or 6V BEC.  Have not had any problems even after 8 continous flights!!

But be very careful on keeping the voltage up.  I had a problem once when I was sharing the same battery for the Motor / Rx.  The motor sucked up the entire battery power and the Rx went for a reset and I lost control for about 5 secs.  Lucky for me, the plane was flying straight and level and I regained control and landed it.  Just keep in mind, low voltage and 2.4G never mix.  So keep your charges high while flying on these Rxs. 

For that, I would suggest you to use Lipos through a BEC.  Or if you are using servos which can take 7.4V direct (the AR6200 can take 7.4V direct), then use 2s 7.4V Lipos direct without a BEC.

Another option is to go in for A123 Rx packs which are being sold now.  They are nothing but 2 A123 cells soldered in series.  So you would have a 6.6 V battery pack which has better discharge curves and better life than lipos.  You dont have to use a BEC for this.

- Chan

Chan,
Is there anyone who is selling the A123 in India yet ?
I have been looking for them for quite sometime.
Let me know.
-Gaurav

Hey Gaurav,

No one in India stocks A123 packs still.  Try aircraft-world.com or some other rc sites where they stock A123 Rx packs.  A friend of mine had bought one from Ebay.  Works great.

- Chan

Thanks Chan. From what i have read so far i like A123. and find them superior to LiPo with BEC , simply because i do not trust the BEC in between. I am trying to find a good source from where i can source the A123 packs. If you know any good sites that ship to India, that would be great.

BTW Futaba has discontinued the 10C .. Are you planning to get the new 10CG ?

Yeah Gaurav,

If you see some of my previous posts, I would have mentioned the same thing.  Even I dont want to trust BECs.  Moreover, I am also planning on a failsafe unit with a reserve battery pack (not as huge as the original Rx pack if using lipos).  Lets see what I can work out.

http://aircraft-world.com has been very reliable and they stock Hyperion A123s which are very good in quality.  get two cells and do the soldering yourself.  There is a very good tutorial on the site if you are interested.

- Chan

Guys ,
I think a lot of the talk of fail safe over fail safe etc is  a whole lot of over exaggeration.
I have been using BEC's for over 2 years now with full electric set ups and have not had a failure till date .
That too I have been using them directly from the flight packs .

Chan you are talking of all sorts of safety factors on your aircraft to ensure against failure but  seem to ignore the fact that flying at Sholavaram is today inherently unsafe , despite all your fail safe and safety measures I guess the external risks far outweigh the  fail safe technology you are writing about.
As you know I have documented the near misses on a single day of flying  and you have also accepted that there were similar 3 near misses last week and similar the week before  so are you talking of  your safety loaded plane flying in such an environment .

I am once again raising this point that  flying under such circumstances is  a serious threat to the hobby itself  in Tamilnadu in particular .

Which as aero modelers we seem to ignore  >:(

There is no point having all safety features in the air and flying in unsafe conditions.

This is not a criticism of any individual and I hope it is taken in the right spirit.
sai

Sai,
Multiple fail-safe and being particular about the battery/switches is not exaggeration. When dealing with big airplanes like 30% gassers that Chan and I are working up on, concern on safety is a must.

I am not criticizing your post, but flying gassers is a different league than electrics, where a lot is at stake, and even a small failure of a critical equipment like a switch, battery or a BEC could cause several thousand dollar damage, plus could take lives of people. 

It would be great if you could stock some A123 battery packs, and chargers. I think its a great technology and there would be many takers for it in the Indian RC community.

Just my 2 bits,
-Gaurav

I have flown all my helis with some sort of BEC, never had a problem.  The key is to not push the limits, and quit flying when you "know" or even when you "feel" that you have used up enough of the RX battery.  Having a voltage checker would be heavily recommended, or get a BEC with on board power indicator.  

I stop flying when my voltage indicator slips down even one step below full, as 3D flying on a 50 size heli can put significant drain on the RX battery. I always carry two or three RX lipos to fly until I am satisfied, without taking foolish risks.

The way things stand at Sholavaram I dont think  you need a gasser to have an accident  todays  flying it self is quite close

Gaurav ,
I think a BEC on any electric connected to the flight pack is  a far more difficult application for the BEC than  a stand alone  receiver BEC  all I said is I have not had a problem with that itself.

Sai

Criticism taken in good sense uncle... I totally understand and accept the risks of flying in Sholavaram.. But when considering gassers, we guys dont have any alternate field today!! Sholavaram in the early mornings are fine (6 to 8am) but even then, the safety factors have to be considered.  In air flight safety is something that we can handle and should not compromise on specially on giant scales.  Ground safety is also equally important but now that is pretty much out of hands until some drastic step is taken.  So let us adhere to as much safety standards as possible atleast till an alternate spot is found.  The ISKCON spot is also good but it is also near a garbage dump and one more thing is the sand that would get into the engines.  Kovalam and ISKCON would become pretty much unusable after a couple of months because of the rains!!  So let us hope some sort of solution is arrived at as far as the flying field is considered.

- Chan

So do i read between the lines and go in for the 'reliable' NiCd or NiMh 4.8v - 6v combination?
coz the lipos are going to need a BEC and in both cases the consumption of power can't be monitored.
I guess there are people who swear by Lipos and there are others who are Die hard Nicad fans!