Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Aux Battery Idea Was: Speaking of Aux Batteries

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
Dave Saylor



Joined: 11 Jan 2015
Posts: 145
Location: GILROY, CA

PostPosted: Sun Sep 08, 2019 9:01 pm    Post subject: Aux Battery Idea Was: Speaking of Aux Batteries Reply with quote

We're going to remodel our panel soon.  Some of the things I want to do better than the existing setup are to simplify operation, provide anti-sag for starting, and provide some backup power.

Most of the components I plan to install have main power and aux power inputs.  Aux power inputs (also called aircraft power 2, etc) would be powered from the aux (anti-sag) bus.  Almost everything on the aux bus would also be primarily powered from the main bus, and only be pulling from the aux when the main voltage is low.  That's all built in to the components.
I don't mind an extra battery, especially if I can convince myself that a small EarthX is something I can live with.  It does a few nice things, including limiting is charge rate.  But that's not what I'd like to discuss now.  I would like comments on this anti-sag idea.
I think separating the starter contactor coil from the main bus would eliminate the timeliness issue that Bob described:
  The 'trick' is all in the timing. Boost
  has to initiate before the starter
  contactor closes and needs to sustain
  past (1) rise in battery voltage due
  to expiration of inrush current or (2)
  contactor opening, which ever happens
  first. I'm fiddling with some ways to
  get that to happen.

Here's a work in progress.  Obviously not complete, no alternator shown, lot's of detail omitted, etc, but the starter contactor power is shown.  That's the key, unless I'm missing something.
Please ignore the current ratings.  They're not complete yet.

--Dave


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List



Anti_sag_bus.pdf
 Description:

Download
 Filename:  Anti_sag_bus.pdf
 Filesize:  65.4 KB
 Downloaded:  14 Time(s)


_________________
--Dave
KWVI
Back to top
View user's profile Send private message
user9253



Joined: 28 Mar 2008
Posts: 1436
Location: Riley TWP Michigan

PostPosted: Mon Sep 09, 2019 3:43 am    Post subject: Re: Aux Battery Idea Was: Speaking of Aux Batteries Reply with quote

The starter contactor is normally energized by switching the positive wire.
It is dangerous to switch the negative wire. If that wire ever gets shorted
to ground, the starter motor will spin the prop, causing damage or injury.


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
Joe Gores
Back to top
View user's profile Send private message
Dave Saylor



Joined: 11 Jan 2015
Posts: 145
Location: GILROY, CA

PostPosted: Mon Sep 09, 2019 11:00 am    Post subject: Aux Battery Idea Was: Speaking of Aux Batteries Reply with quote

Good point, and easy enough.  Thanks!

On Mon, Sep 9, 2019 at 4:48 AM user9253 <fransew(at)gmail.com (fransew(at)gmail.com)> wrote:

Quote:
--> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>

The starter contactor is normally energized by switching the positive wire.
It is dangerous to switch the negative wire.  If that wire ever gets shorted
to ground, the starter motor will spin the prop, causing damage or injury.

--------
Joe Gores




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=491247#491247






===========
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
===========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer" target="_blank">http://wiki.matronics.com
===========
b Site -
          -Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
===========





- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
--Dave
KWVI
Back to top
View user's profile Send private message
Dave Saylor



Joined: 11 Jan 2015
Posts: 145
Location: GILROY, CA

PostPosted: Mon Sep 09, 2019 12:03 pm    Post subject: Aux Battery Idea Was: Speaking of Aux Batteries Reply with quote

Thanks Bob,

What is the cost of accidently leaving the aux battery on during start?  Is it just a sag, or does starter-sized current try to run through the small relay and associated wiring?  If the main is weak, will the aux battery work that much harder?  I'm concerned that a relatively simple mistake like leaving the aux batt on during start will do some damage.

(I've put switches in the wrong position before...)
--Dave

On Mon, Sep 9, 2019 at 10:13 AM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
Quote:

Here's a work in progress.  Obviously not complete, no alternator shown, lot's of detail omitted, etc, but the starter contactor power is shown.  That's the key, unless I'm missing something.

  There are no 'timing' issues with using
  a second battery for brownout protection.
  Consider Z-35 for second battery and
  simply leaving the aux battery relay
  open until after the engine is running.



  Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

_________________
--Dave
KWVI
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group