[NSRCA-discussion] Part 2-Its a miracle!!!

Wed Sep 3 08:23:16 AKDT 2008

Correct,  I still use separate regulators for each battery.  This system is smart that isolates the bad battery if something goes wrong.  In this way,  the bad battery won't drain the good one.  The LED in the receiver tells you if the battery has been isolated.  

--
Vicente "Vince" Bortone

-------------- Original message -------------- 
From: "Jay Marshall" <lightfoot at sc.rr.com> 

As I read the literature, the dual battery setup is designed to provide a heavier buss for more current. It does not solve the problem of a failed battery(s). This could effectively add even more drain. The ideal setup still seems to be dual battery packs with dual regulators, or some other means to isolate a failed pack.

Jay Marshall 
-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of vicenterc at comcast.net
Sent: Wednesday, September 03, 2008 11:44 AM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Part 2-Its a miracle!!!

Gray,

Yes, high drain could have been the problem.  Since the plane is in good condition probably you can check.  I think you should consider using two batteries of your preference.  I starting to use the 9100 receiver that already has two power inputs.  Check details here:

http://www.horizonhobby.com/Products/Default.aspx?ProdID=SPMAR9100

--
Vicente "Vince" Bortone

-------------- Original message -------------- 
From: Gray E Fowler <gfowler at raytheon.com> 

Vicente 

The Robbe charger has a setting for soft peak, which is to be used for NiMH. This is what I had. I cycled twice before using this new battery..what I remember was getting about 1300 Mah from this 1450 mah pack. I think there may be a "high drain" problem on the plane in addition. 

Gray Fowler
Senior Principal Chemical Engineer
Radomes and Specialty Apertures
Technical Staff Composites Engineering
Raytheon 

vicenterc at comcast.net 
Sent by: nsrca-discussion-bounces at lists.nsrca.org 
09/03/2008 09:42 AM 
Please respond to
General pattern discussion <nsrca-discussion at lists.nsrca.org>
ToGeneral pattern discussion <nsrca-discussion at lists.nsrca.org> 
cc
SubjectRe: [NSRCA-discussion] Part 2-Its a miracle!!!

Gray, 

Yes, that is good news.  Clearly the battery was the problem.  I had heard that some chargers get a "false peak" and stop charging when the battery is not really fully charged.  I wonder if this was the problem. 

--
Vicente "Vince" Bortone 

-------------- Original message -------------- 
From: Gray E Fowler <gfowler at raytheon.com> 

Lance and I went out and found the plane right where it was supposed to be. Do not know how I missed it the first day, so I am going to say that someone went into the woods Monday night and moved it . 

What  is amazing in the minimal damage the plane has considering it went straig ht in from 200 feet, albeit at a slow speed. The horrible reverbed cracking sound Keith and I heard was the carbon fiber wing tube breaking. Both wings have limited leading edge damage, the stab has a golfball size divot on the R LE, an easy to repair crack in the fuse (buckle failure) behind one wing and a little nose ring area damage. That is all. 

The battery pack had broken the 3/8 bals a stic ks on impact that were bonded into place (my battery packs are not "removeable" per say) and the battey pack was on the ground at the nose of the plane. The plane was standing vertical  on the undamage spinner being held up by the tree branches.  Once we got home we hooked eveything up and of course it all worked fine. Knowing that the battery pack essentially had the same charge as when the plane went in, Lance took the battery pack home for diagnostics.  Using the Robbe charger he cycled the1450 mah &nbs p;pack down....it read 80 mah. He then charged it and it read 1000 mah. Anthony described a NiMH "brown out" and that is starting to make alot of sense.  6 volt packNiMH , drained does not just die like a 4.8 volt NiCad. Also an important note is I now think the plane was going in and out of PCM lock. When I tested PCM lock the throttle did cut, but not to low idle. It cut to about 20% throttle (programming error), hence the p
 ulsing
 of the throttle that I exper ienced. If this diagnosis is correct then it is a testament to using PCM as I was able to fly the plane for 45 seconds before impact...had I been closer when the problem started I may have even been able to score a "10" FAI landing (not really-I would have gone for the grass instead of the runway). 

Anyway I am sending the entire radio off for examination, try to see why the battery was so low, and fix the plane for spring. 

Thanks for the ideas 

Gray Fowler
Senior Principal Chemical Engineer
Radomes and Specialty Apertures
Technical Staff Composites Engineering
Raytheon _______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080903/f5fb3c7c/attachment-0003.html>
-------------- next part --------------
An embedded message was scrubbed...
From: "Jay Marshall" <lightfoot at sc.rr.com>
Subject: Re: [NSRCA-discussion] Part 2-Its a miracle!!!
Date: Wed, 3 Sep 2008 16:06:20 +0000
Size: 723
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080903/f5fb3c7c/attachment-0003.mht>