View Full Version : Swift - BEC or Seperate Rx/Servo Battery
frankos72
10-16-2006, 07:05 PM
I'm building with 600 plus, CC 45HV, 7S Emoli's.
Should I get a BEC for the Rx or just use a seperate battery? Also, what BEC or Battery would you suggest.
Jev
Coolice
10-17-2006, 04:36 PM
Hey,
I would suggest a seperate Rx. battery pack and this is how my own Swift is setup.
Many use a BEC without incident, but I'd rather be safe in the knowledge that should the main battery fail I still have control of the flying surfaces.
Plus some BEC's are not all that clean, eg. can pass on interference into the Rx. which then cause glitching problems.
The Swift can also be a little tail heavy and so the small increase in overall weight, which it can carry easy enough brings the C/G forward more.
.
TJRIDE
10-17-2006, 04:58 PM
I would have to agree with Coolice.
I am running a separate RX battery and feel good knowing that I don't have to worry about a BEC causing problems. And it helped with the balance on both the wifes swift as well as my swift.
TJ
:glasses2:
Another vote for the separate Lipo batt/Ubec. A 3S 1320 or 1500 mah and a Koolflight or Medusa Ubec would do very well. I have used Koolflight for quite a while on my nitros without a single problem and get many more flights between charges than with a nicad. I'm waiting to get a "big" electric until the ERaptors finally get into the country and the carbon Swift 620se is released. I'd like to compare the T-rex 600, Logo 14, carbon Swift and the ERaptors before making my choice. The anticipation is killing me!
AV8TOR
10-17-2006, 08:16 PM
Yet another vote for a separate Rx battery. Us a nice large one too as the Swift needs a little nose weight. I am using a 3300 mAh.
Tim Tompkins
10-17-2006, 10:40 PM
I have no problem with balance. I use a 2 cell li-ion pack and a regulator. Very light and 2400 mah's so I can fly as long as I want. BTW I also have the same motor and I went back to 6 cells because of the head speed was over 2300 rpms with a 9 tooth pinion. Now I get h/s of 1900+ and the motor runs cool enough to lick. TimT
frankos72
10-17-2006, 11:25 PM
Great I was leaning towards seperate battery since thats what is shown in the manual.
It seems that some of you are using nicad/nimh and some lipo.
I'm curious as to which type everyone is choosing and why.
Thanks for all the help!
Jev
Oh and I have yet another question but a slight diff topic, Tim I got this question after your response. It's over at http://www.helifreak.com/viewtopic.php?t=22043
Thanks again!
AV8TOR
10-18-2006, 07:52 AM
My sub c 3300 mAh is a NiMh battery. I chose it over NiCd to get away from memory issues in NiCd batteries. LiPo’s need a voltage regulator and I considered it something else to fail. If you go with a NiMh battery all are not created equal. You need a very low impedance battery around 5-6 m/ohm if you are using digital servos. Digitals need power fast and when you have 4 of them with a high impedance battery the power will drop.
I prefer a bec.
I use a medusa 6v 3a.
Reciever packs are dead weight unless your main battery is marginal for your power setup. More complexity in the reciever pack/switch/regulator setup, and one more thing to charge at the field.
I've never heard about a reciever pack/switch setup failing on the ground, I've heard of plenty failing in flight .
I've never heard about a bec failing in flight , I've heard of a few fail on the ground, when power is first connected though.
EddieNewYork
10-31-2006, 12:49 PM
I asked the same exact question several months ago. In the end I decided to go with a Koolflight Ultimate BEC, mainly becasuse of the reasons stated by NTM. I'm running 3 x S9252 and 1 S9254 and so far I'm loving this UBEC.
I have used a koolflight 35v Ubec for over 5 months now on my swift and it has worked very well, even after a couple of dumb-thumb crashes.
Cheers,
Tom C