[NSRCA-discussion] Receiver packs

Sat Feb 14 10:09:23 AKST 2009

Rich:
I don't necessarily distrust LiPo or Li Ion any less than a NiCad or NiMh pack.  If anything, my experience to date shows them to be very reliable (100% so far).  I really like the way perform as they age as contrasted with NiMH in particular and the virtually zero self discharge is a very convenient thing too.  Having said all that, I use a dual batteries and regulators because anything can happen, so why not take out a cheap insurance policy to save your airplane in the event of a failure?  As it turns out, you can get more capacity, more current on demand and lighter weight with a pair of LiPo's and dual regulators than a 5 cell NiMh solution, and you get the same exact output (same servo speed & torque) all day long.  I've run a lot of NiMh dual setups unregulated no big IMAC stuff in the past and you definitely feel the degraded performance as the batteries discharge throughout the day.

Regards
Ed

----- Original Message ----- 
  From: Richard Strickland 
  To: General pattern discussion 
  Sent: Saturday, February 14, 2009 1:37 PM
  Subject: Re: [NSRCA-discussion] Receiver packs

  Jerry--just a couple thoughts:  I will probably never use a battery for a receiver/flight pack again that I haven't been in charge of its history.  If you've been paying attention to its characteristics since new, we can generally tell when they start to lose capacity--and for me, there was a point on the ESV when it got there, I got a little nervous about going up 'one more time'.  When it would approach that point after about five flights, then I would figure it was 1. if early in its career--then to cycle and 2. if in to the second or third year(sometimes longer) it was time to retire it.  Nicads for me have been pretty reliable that way and I've been comfortable running one pack.  You can still go to five cells in nicads for additional capacity and power with a regulator and still have that reliability.  I think most of the guys that have gone to lipos can enjoy the increased capacity and power along with an increased discharge rate in a smaller, lighter package.  But I don't get the impression that they trust them like nicads.  Probably the best thing to do is monitor your batteries of any type with a good, loaded ESV to keep an eye out for any unusual battery behavior.  The two battery debate is a little like the single versus twin debate in full scale airplanes--some guys think twins just have double the chances to fail.
  All that said, I understand some of the new receivers are a little touchy regarding low voltage situations.  I had an older receiver in an airplane that I bought used with a 'new' battery--turned out the battery was bad--but got a warning(hold) and was able to land--but showed NO volts afterward. 
  Chances are with the newer stuff, it may not have made it back on the ground in one piece.  So using a 5 cell nicad or 2 cell lipo with regulator may not be a bad idea and monitor with a good loaded ESV.
  FWIW
  Richard

------------------------------------------------------------------------------
  From: jjvoth at mtelco.net
  To: nsrca-discussion at lists.nsrca.org
  Date: Fri, 13 Feb 2009 20:32:46 -0600
  Subject: Re: [NSRCA-discussion] Receiver packs

  Thanks for the info guys
    ----- Original Message ----- 
    From: Vicente "Vince" Bortone 
    To: General pattern discussion 
    Sent: Friday, February 13, 2009 8:28 PM
    Subject: Re: [NSRCA-discussion] Receiver packs

    Hi Jerry,

    I have been using two li-po using the tech-aero double regulator http://www.tech-aero.net/plr5-dr2.htm  The capacity I am using now is 930 mah, 2 cells  batteries.  I know that I can fly at least 6-8 times.  After that, I am brain dead.

    VB

    ----- Original Message -----
    From: "Richard Strickland" <pamrich47 at hotmail.com>
    To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
    Sent: Friday, February 13, 2009 8:01:03 PM GMT -06:00 US/Canada Central
    Subject: Re: [NSRCA-discussion] Receiver packs

    Jerry, I think the short answer is no.  But there has been much discussion regarding dual packs for back-up.  An example ot single pack usage is using a 2 cell lipo at around 780-800ma for practice and 340-380ma for contests to make weight.  These are used with voltage regulators with variing outputs.
    RS

    > From: jjvoth at mtelco.net
    > To: nsrca-discussion at lists.nsrca.org
    > Date: Fri, 13 Feb 2009 17:32:25 -0600
    > Subject: Re: [NSRCA-discussion] Receiver packs
    > 
    > Sorry, I said that wrong. I meant are two packs needed to power the flight 
    > pack.
    > ----- Original Message ----- 
    > From: "Jerry Voth" <jjvoth at mtelco.net>
    > To: "NSRCA" <nsrca-discussion at lists.nsrca.org>
    > Sent: Friday, February 13, 2009 5:23 PM
    > Subject: [NSRCA-discussion] Receiver packs
    > 
    > 
    > > This has probably come up many times but I'd like to know if it's 
    > > necessary
    > > to use two Li-Fe packs for the radio and servos
    > > _______________________________________________
    > > NSRCA-discussion mailing list
    > > NSRCA-discussion at lists.nsrca.org
    > > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
    > >
    > 
    > 
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