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Michael Wynn

Joined: 10 Jan 2006
Posts: 148
Location: San Ramon, CA

Posted: Wed Jun 24, 2009 10:20 am Post subject: Battery Proximity and mounting

Hi all,

  

 I am building an all-electric RV 8 with dual electronic ignition.  I  plan to use two P680 batteries.  As I was sorting out where to put them, I  had decided to strap them together and put them behind the firewall on the  right.

  

 A building buddy asked the question, are they okay to be strapped  together?  Are there any failure modes where one might fail and take out  the other out at the same time?  

  

 I thought I would ask the same question to the list and/or Bob.  I  really like the "change one out every annual" approach described in the  Aeroelectric book, which is why I am going with two identical batteries.   The new and improved section on batteries does not describe explosion or  melt-down as a likely failure of RG batteries so I had thought that mounting  them together and in the inside of the plane would be okay.

  

 In retrospect, I can see that I should have built in the mounting system  before I riveted on the front bottom skin.  As is, I am still scratching my  head about where exactly to put them and how to property secure them to the  airframe.  I am very open to suggestions.

  

 Regards,

  

 Michael Wynn

 RV 8 FWF

 San Ramon, CA

 Huge Savings on Popular Laptops only at Dell.com. Shop Now!

  [quote][b]

_________________
Michael Wynn
RV 8
San Ramon, CA

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 25, 2009 7:15 am Post subject: Battery Proximity and mounting

At 01:14 PM 6/24/2009, you wrote:

  	  Quote: 	
		   Hi all,

  

 I am building an all-electric RV 8 with dual electronic ignition.  I plan to use two P680 batteries.  As I was sorting out where to put them, I had decided to strap them together and put them behind the firewall on the right.

  

 A building buddy asked the question, are they okay to be strapped together? 	


   Yes



  	  Quote: 	
		     Are there any failure modes where one might fail and take out the other out at the same time?  	


   No.



  	  Quote: 	
		    

 I thought I would ask the same question to the list and/or Bob.  I really like the "change one out every annual" approach described in the Aeroelectric book, which is why I am going with two identical batteries.  The new and improved section on batteries does not describe explosion or melt-down as a likely failure of RG batteries so I had thought that mounting them together and in the inside of the plane would be okay.

  

 In retrospect, I can see that I should have built in the mounting system before I riveted on the front bottom skin.  As is, I am still scratching my head about where exactly to put them and how to property secure them to the airframe.  I am very open to suggestions. 	


    Are you sure they want to go forward? A lot of

    my RV-8 builders had to put them in the tail

    for the purposes of satisfying CG limits.



 

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------



     [quote][b]

Flagstone(at)cox.net
Guest

Posted: Thu Jun 25, 2009 9:01 am Post subject: Battery Proximity and mounting

Bob:

  

 Could you expand further on your answer?   Are there any failure modes or circumstances that would cause an RG battery to  fail and drag down the entire system, including taking the alternator  off-line?

  

 Thanks

  

  

  

  ---

Speedy11(at)aol.com
Guest

Posted: Thu Jun 25, 2009 10:07 am Post subject: Battery Proximity and mounting

Michael,

 I know other builders have mounted batteries side-by-side with no  problems.  Also, they are mounted that way in my golf cart with no  problems.  In my opinion, if you can leave a small airspace  between them (say 1/4 to 1/2 inch) then I would do that.

 I mounted one P680 in the lower portion of the front baggage and one behind  the aft baggage.  I put the aft one there for W&B and it turns out that  worked great because my 8A is within CG limits at all weights and  configurations even with a 3 blade prop and IO-390.  Actually I put  everything as far aft as I could.

 Building a bracket for the front battery was challenging.  You can see  what I did at http://www.rv-8a.net/2005.htm and  scroll down to 16 Dec 05 and at http://www.rv-8a.net/2006.htm -  scroll down to 20 Mar 06 and more photos scattered throughout http://www.rv-8a.net/2008.htm.  I  bought the steel jackets for the batteries and made those an integral part of  each bracket.

 Regards,

 Stan Sutterfield

 Inspected, ready to fly

  

  	  Quote: 	
		  I am    building an all-electric RV 8 with dual electronic ignition.  I     plan 

to use two P680 batteries.  As I was sorting out where to put    them, I  had 

decided to strap them together and put them behind the    firewall on the  right.



A building buddy asked the question, are    they okay to be strapped  

together?  Are there any failure modes    where one might fail and take out  the other



out at the same    time?  



I thought I would ask the same question to the list and/or    Bob.  I  really 

like the "change one out every annual" approach    described in the  

Aeroelectric book, which is why I am going with two    identical batteries.   The

new and 

improved section on    batteries does not describe explosion or  melt-down as 

a likely    failure of RG batteries so I had thought that mounting  them 

together    and in the inside of the plane would be okay.



In retrospect, I can see    that I should have built in the mounting system  

before I riveted on    the front bottom skin.  As is, I am still scratching my  

head    about where exactly to put them and how to property secure them to the     

airframe.  I am very open to    suggestions.



Regards,



Michael Wynn 	


 

  

 Make your summer sizzle with fast and easy recipes for the grill.

  [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 25, 2009 11:09 am Post subject: Battery Proximity and mounting

At 11:58 AM 6/25/2009, you wrote:

  	  Quote: 	
		   Bob:

  

 Could you expand further on your answer?  Are there any failure modes or circumstances that would cause an RG battery to fail and drag down the entire system, including taking the alternator off-line? 	


   Back in the bad ol' days the lead-acid battery

   was prone to various forms of leaking, outgassing,

   and cells that shorted when the residue of flaking

   plates piled up too high.



   RG battery failures are very benign . . . the device

   simply stops storing and then giving back electrical

   energy. They don't short like the flooded battery.

   However, in defense of flooded cell devices: Had we

   bothered to maintain them by swapping out an otherwise

   working battery when its TESTED capacity dropped

   below design goals for battery only operations,

   the vast majority of unhappy experiences with this

   venerable technology could have been prevented.



   The short answer is that there are no failure modes

   that cause a battery to take a system down assuming

   that it is not abused. Most abuse situations arise

   from other system failures such as extended over

   voltage conditions:

  

  http://aeroelectric.com/Pictures/Batteries/Odyssey_OV/Odyssey_OV_1.jpg 



  http://aeroelectric.com/Pictures/Batteries/Internal_Fire/Picture%20001.jpg 



   Given that you've embraced the new-battery-per-year

   philosophy for battery maintenance and assuming you

   plan to incorporate active notification of low voltage

   and automatic mitigation of over-voltage conditions,

   any concerns for battery failure are unwarranted.



 

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------



     [quote][b]

jquinn3(at)gmail.com
Guest

Posted: Thu Jun 25, 2009 1:42 pm Post subject: Battery Proximity and mounting

Bob,One of the links below (http://www.rv-8a.net/2005.htm)  shows the Tempo marine or race car type battery switches being used in lieu of battery contractors. This seems like a very good idea, i.e. less cost, less weight and almost absolute reliability (assuming you don't loss the keys). Your comments?

  

On Thu, Jun 25, 2009 at 13:02,  <Speedy11(at)aol.com (Speedy11(at)aol.com)> wrote:

[quote]        Michael,

 I know other builders have mounted batteries side-by-side with no  problems.  Also, they are mounted that way in my golf cart with no  problems.  In my opinion, if you can leave a small airspace  between them (say 1/4 to 1/2 inch) then I would do that.

 I mounted one P680 in the lower portion of the front baggage and one behind  the aft baggage.  I put the aft one there for W&B and it turns out that  worked great because my 8A is within CG limits at all weights and  configurations even with a 3 blade prop and IO-390.  Actually I put  everything as far aft as I could.

 Building a bracket for the front battery was challenging.  You can see  what I did at http://www.rv-8a.net/2005.htm and  scroll down to 16 Dec 05 and at http://www.rv-8a.net/2006.htm -  scroll down to 20 Mar 06 and more photos scattered throughout http://www.rv-8a.net/2008.htm.  I  bought the steel jackets for the batteries and made those an integral part of  each bracket.

 Regards,

 Stan Sutterfield

 Inspected, ready to fly

  

  	  Quote: 	
		  I am    building an all-electric RV 8 with dual electronic ignition.  I     plan 

to use two P680 batteries.  As I was sorting out where to put    them, I  had 

decided to strap them together and put them behind the    firewall on the  right.



A building buddy asked the question, are    they okay to be strapped  

together?  Are there any failure modes    where one might fail and take out  the other



out at the same    time?  



I thought I would ask the same question to the list and/or    Bob.  I  really 

like the "change one out every annual" approach    described in the  

Aeroelectric book, which is why I am going with two    identical batteries.   The

new and 

improved section on    batteries does not describe explosion or  melt-down as 

a likely    failure of RG batteries so I had thought that mounting  them 

together    and in the inside of the plane would be okay.



In retrospect, I can see    that I should have built in the mounting system  

before I riveted on    the front bottom skin.  As is, I am still scratching my  

head    about where exactly to put them and how to property secure them to the     

airframe.  I am very open to    suggestions.



Regards,



Michael Wynn 	


 

  



 Make your summer sizzle with fast and easy recipes for the grill.

     	  Quote: 	
		  



ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


[b]

Flagstone(at)cox.net
Guest

Posted: Thu Jun 25, 2009 2:26 pm Post subject: Battery Proximity and mounting

Bob:

  

 Thanks, that's good to hear.  If I could take  this one step further for the RG batteries:

  

 If there is a zero probability of battery failure  (assuming it's not abused and maintenance benefits aside), strictly from the  battery's contribution to system reliability, is there is any benefit  gained from a dual battery as compared to single battery  installation?

  

 Thanks

  

 [quote]   ---

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 25, 2009 2:54 pm Post subject: Battery Proximity and mounting

Re: Battery Proximity and mounting

 From: James Quinn <jquinn3(at)gmail.com>



 Bob, 

 One of the links below (http://www.rv-8a.net/2005.htm )  shows the Tempo marine or race car type battery switches being used in lieu of battery contractors. This seems like a very good idea, i.e. less cost, less weight and almost absolute reliability (assuming you don't loss the keys). Your comments?



      A number of airplanes (including type

      certified) have used battery switches

      in lieu of contactors. A TriPacer I used

      to fly had manual battery switch AND a

      high current, manually operated starter

      switch. No contactors at all.



      So there's nothing particularly unusual

      about the idea. A decision to substitute

      manual switches for contactors needs to meet

      design goals for convenient accessibility

      under all flight conditions: Both normal

      and those which anticipate un-intended

      arrivals with the earth. Recall that the

      battery switch is designed make the

      ship's wiring max-cold when off.



 

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------



     [quote][b]

retasker(at)optonline.net
Guest

Posted: Thu Jun 25, 2009 3:16 pm Post subject: Battery Proximity and mounting

I think if you read the response, he is not saying that there is a zero 

probability of battery failure, just essentially a zero probability of a 

failure that will also bring down the whole system.



I.e. the battery could fail so that it no longer can supply current, but 

this failure would have no effect on the rest of the system if you still 

had a second battery.  Obviously, if you have only one battery and it 

stops supplying current that you need then you have a problem.



Dick



Flagstone(at)cox.net wrote:

[quote] Bob:

  

 Thanks, that's good to hear.  If I could take this one step further 

 for the RG batteries:

  

 If there is a zero probability of battery failure (assuming it's not 

 abused and maintenance benefits aside), strictly from the battery's 

 contribution to system reliability, is there is any benefit gained 

 from a dual battery as compared to single battery installation?

  

 Thanks

  



     ---

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 25, 2009 3:55 pm Post subject: Battery Proximity and mounting

At 05:19 PM 6/25/2009, you wrote:

Bob:



Thanks, that's good to hear.  If I could take this one step further 

for the RG batteries:



If there is a zero probability of battery failure (assuming it's not 

abused and maintenance benefits aside), strictly from the battery's 

contribution to system reliability, is there is any benefit gained 

from a dual battery as compared to single battery installation?



   The reasons for dual batteries are few and specific.

   Z-14 calls for dual batteries because you have dual

   systems. If you have one alternator and an electrically

   dependent engine, then Z-19 suggests a means by which

   an alternator failure can be responded to by having

   engine and instruments supported by separate batteries

   while operating in the endurance mode.



   We've also discussed appliances not designed to live

   in the real world of airplanes and require support

   of a battery that is independent of the cranking

   battery.



   I neglected ask why you were considering two batteries.



        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

Flagstone(at)cox.net
Guest

Posted: Thu Jun 25, 2009 5:06 pm Post subject: Battery Proximity and mounting

Bob:



Are any of those reasons for Z-14 as a result of the design and performance 

of the RG batteries by themselves, or are they the result of other potential 

failures extraneous to the batteries?  If any of the reasons are a result of 

the batteries, what are they and what are the probabilities of them 

happening?



Another group member stated that "the battery could fail so that it can no 

longer supply current".  He may be correct that I misunderstood your 

previous answer.  I would consider that within the scope of my previous 

question, in that it seems to me that if a battery were to suddenly be 

unable to supply current, it would be the result of some sort of internal 

failure.  If that in fact can happen, what are the circumstances that would 

cause that, and what are the probabilities of it happening?



I intend to use to use two batteries for the maintenance benefits you 

outline in your book and for the additional cranking power.



Right now I'm just trying to get a clear understanding of the RG battery's 

reliability and performance limitations.



Thanks



---

Michael Wynn

Joined: 10 Jan 2006
Posts: 148
Location: San Ramon, CA

Posted: Thu Jun 25, 2009 6:37 pm Post subject: Battery Proximity and mounting

First off, thank you all for the replies and the group think.

  

 My main reason for two batteries is the dual electronic ignition.   Claus at Lightspeed strongly suggests a back-up battery if you are completely  electrically dependent.  I have read the Aeroelectric book through several  times.  I suppose that I may be in overkill mode, but I have a main and  back-up alternator (B&C 60 Amp and 20 amp).  While I have not yet done  the wiring or really completed the drawings, I was thinking strongly of a  Vertical Power VP 100 around a system that is basically a Z12 with a second  battery.  The VP will not really support a Z14 style architecture.

  

 If I am going to have a second battery per the ignition system's  manufacturers recommendation, it seems reasonable to use identical batteries and  plan a yearly rotation.  Is this complete overkill?  Adding a cross  feed connector gives you the opportunity to have additional cranking power in  case of starting difficulties.

  

 Thoughts?

  

 Michael Wynn

 RV 8

 San Ramon

  

  In a message dated 6/25/2009 4:56:55 P.M. Pacific Daylight Time,  nuckolls.bob(at)aeroelectric.com writes:

  	  Quote: 	
		  -->    AeroElectric-List message posted by: "Robert L. Nuckolls, III"    <nuckolls.bob(at)aeroelectric.com>



At 05:19 PM 6/25/2009,    you wrote:

Bob:



Thanks, that's good to hear.  If I could take    this one step further 

for the RG batteries:



If there is a zero    probability of battery failure (assuming it's not 

abused and maintenance    benefits aside), strictly from the battery's 

contribution to system    reliability, is there is any benefit gained 

from a dual battery as    compared to single battery installation?



   The reasons for    dual batteries are few and specific.

   Z-14 calls for dual    batteries because you have dual

   systems. If you have one    alternator and an electrically

   dependent engine, then Z-19    suggests a means by which

   an alternator failure can be    responded to by having

   engine and instruments supported by    separate batteries

   while operating in the endurance    mode.



   We've also discussed appliances not designed to    live

   in the real world of airplanes and require    support

   of a battery that is independent of the    cranking

   battery.



   I neglected ask why you    were considering two batteries.



        Bob . .    .



            ---------------------------------------

        ( . .    .  a long habit of not thinking   )

           ( a thing wrong, gives it a superficial )

           ( appearance of being right . . .       )

           (                                             )

        (                     -Thomas Paine 1776-  )

             ================================================= Use   utilities  Day  ================================================               - MATRONICS WEB FORUMS  ================================================             - List Contribution Web Site  sp;                             ===================================================



	


 Shop Popular Dell Laptops now starting at $349!

  [quote][b]

_________________
Michael Wynn
RV 8
San Ramon, CA

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 25, 2009 8:23 pm Post subject: Battery Proximity and mounting

At 07:59 PM 6/25/2009, you wrote:

 	  Quote: 	
		  



Bob:



Are any of those reasons for Z-14 as a result of the design and 

performance of the RG batteries by themselves, or are they the 

result of other potential failures extraneous to the batteries?  If 

any of the reasons are a result of the batteries, what are they and 

what are the probabilities of them happening?


	


   Z-14 is the "mother of all electrical systems" intended

   to address the design goals for probably less than 1%

   of the OBAM aircraft fleet. This would be the Lancair

   or Glasair with fully redundant IFR panels on both

   pilot seats wherein the aircraft's missions often

   include two rated pilots and a high percentage of

   flight in IMC.



   Batteries swapped out when their battery-only endurance

   capabilities drop below 2+ hours are still cranking

   and engine nicely . . . and a battery this capable is

   exceedingly unlikely to go south on you en route to

   aunt Martha's.



   For my purposes and for the purposes of the majority

   of the OBAM fleet, Z-13/8 with a battery maintenance

   program offers SYSTEM reliability that is head and

   shoulders above the majority of TC fleet up to and

   including some twin turbine powered aircraft.



 	  Quote: 	
		  Another group member stated that "the battery could fail so that it 

can no longer supply current".  He may be correct that I 

misunderstood your previous answer.  I would consider that within 

the scope of my previous question, in that it seems to me that if a 

battery were to suddenly be unable to supply current, it would be 

the result of some sort of internal failure.  If that in fact can 

happen, what are the circumstances that would cause that, and what 

are the probabilities of it happening?


	


   Can't put a number on "probability" and if I

   could, it probably wouldn't be significant to

   you. The point about battery technology and

   service life is that hundreds of thousands of

   airplanes have launched into IFR with a single generator

   and single flooded battery with a high probability

   of a now-sweat termination of the flight. The

   demonstrated level of system reliability was such

   that many pilots exploited the capability with

   little concern for system failure. The majority

   of accidents were (and still are) seeded by

   poor judgement and/or conditions beyond

   control of the pilot that were not related

   to system reliability.



   Now we can easily install two engine driven

   power sources to charge a well maintained,

   very user-friendly RG battery. A combination

   that reduces risks of power starvation to

   still lower numbers.



   If you're willing to jump in a rented C182

   and launch into the grey with equipment

   certificated 30 years ago, then getting into

   your RV fitted with Z-13/8 + RG battery has to

   be more comfortable yet. Bottom line is that with

   either airplane, your risk for experiencing

   an unhappy day in the cockpit has more to

   do with what's between your ears than with

   what's under the cowl.



 	  Quote: 	
		  I intend to use to use two batteries for the maintenance benefits 

you outline in your book and for the additional cranking power.


	


    Dual batteries are indicated only for those special

    conditions I cited earlier. If you don't have those

    configurations . . . dual batteries are only a cost,

    volume and weight burden on your project.



 	  Quote: 	
		  Right now I'm just trying to get a clear understanding of the RG 

battery's reliability and performance limitations.


	


    If all you want is more cranking power, install ONE

    bigger battery. But cranking power of RG batteries

    is so much better than their flooded counterparts

    that we're installing systems like Z-13/8 with a small

    fraction of the hardware weight in a 1975 Cessna

    182. Unless you have operational features that

    encourage dual batteries, please consider installing

    a single 17 to 18 a.h. RG battery. You can always

    up-size later. But consider leaving 16 pounds of

    hardware on the ground until you KNOW you need it.

    16 extra pounds of baggage or fuel is USEFUL . . . 16

    unnecessary pounds of battery is  . . . well . . .

    you know.



    I'm betting you'll never need it.



    Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Jun 25, 2009 8:33 pm Post subject: Battery Proximity and mounting

At 09:29 PM 6/25/2009, you wrote:

First off, thank you all for the replies and the group think.



My main reason for two batteries is the dual electronic 

ignition.  Claus at Lightspeed strongly suggests a back-up battery if 

you are completely electrically dependent.  I have read the 

Aeroelectric book through several times.  I suppose that I may be in 

overkill mode, but I have a main and back-up alternator (B&C 60 Amp 

and 20 amp).  While I have not yet done the wiring or really 

completed the drawings, I was thinking strongly of a Vertical Power 

VP 100 around a system that is basically a Z12 with a second 

battery.  The VP will not really support a Z14 style architecture.



If I am going to have a second battery per the ignition system's 

manufacturers recommendation, it seems reasonable to use identical 

batteries and plan a yearly rotation.  Is this complete 

overkill?  Adding a cross feed connector gives you the opportunity to 

have additional cranking power in case of starting difficulties.



   Don't know about "complete" overkill . . . but

   it's in the 90th percentile.



   Z-13/8 and one battery with EACH ignition enjoying

   it's own fuse on the battery bus is a very

   rational approach. Keep in mind that your

   engine will run fine on ONE ignition. In fact,

   If you find yourself running from the e-bus on

   either Z-11 or Z-13/8, I'd shut off one of the

   two ignition systems and use the power for something

   more useful.



   I'm working an accident case right now where the

   owner/pilot got wrapped around the "reliability

   axle" and designed a dual ignition power distribution

   system guaranteed to fail both ignitions . . . and it did.



   Save your money for an extra GPS or perhaps dual

   wing-levelers. Z-13/8 will keep them all humming

   at much less cost and weight in your airplane . . .

   and easier to install too.



   Better yet, the extra dollars buys stuff that

   ADDS value to the airplane.



   Bob . . .

flyboybob1(at)gmail.com
Guest

Posted: Fri Jun 26, 2009 5:12 am Post subject: Battery Proximity and mounting

Bob,



In the "Battery Proximity and mounting" thread speaking of Z-14 you say:

   Z-14 is the "mother of all electrical systems" intended

   to address the design goals for probably less than 1%

   of the OBAM aircraft fleet. This would be the Lancair

   or Glasair with fully redundant IFR panels on both

   pilot seats wherein the aircraft's missions often

   include two rated pilots and a high percentage of

   flight in IMC.

   ...

   Z-13/8 will keep them all humming

   at much less cost and weight in your airplane . . .

   and easier to install too.



In the "First choice alternator decision" thread you say:

   The purpose of this little dissertation is to suggest

   that much of what's reported as an "alternator

   problem" has nothing to do with the design or

   fabricating processes in the alternator itself.



I have decided on Z-14 to support my electrically dependant engine because

of your second statement!  I'm not concerned with battery failure, I'm

concerned with my ability to assemble a set of components, few as they are,

that will not fail in any circumstance.  The Z-14 design is more reliable

than Z-13/8 by a significant margin because all of us do not have your

capability to assemble the compenents.  Two battery ground connections and

two battery plus connections are a great sleeping aid to me.  I'm using

smaller batteries so the weight penalty is only a few pounds.



Regards,

Bob Lee

N52BL  KR2

Suwanee, GA  USA

92% done only 67% to go!

Speedy11(at)aol.com
Guest

Posted: Fri Jun 26, 2009 6:38 am Post subject: Battery Proximity and mounting

Concur 100%.

 I may remove my extra battery in the future.

 Stan Sutterfield

 Do not archive

  

  	  Quote: 	
		  Unless    you have operational features that

    encourage dual batteries,    please consider installing

    a single 17 to 18 a.h. RG battery.    You can always

    up-size later. But consider leaving 16 pounds    of

    hardware on the ground until you KNOW you need    it.

    16 extra pounds of baggage or fuel is USEFUL . . .    16

    unnecessary pounds of battery is  . . . well . .    .

    you know.



    I'm betting you'll never    need it. 	


 

  

 Make your summer sizzle with fast and easy recipes for the grill.

  [quote][b]

frank.hinde(at)hp.com
Guest

Posted: Fri Jun 26, 2009 7:03 am Post subject: Battery Proximity and mounting

Yup I agree..I have a 7a  with dual El s and electric fuel pumps only (no mechanical pump). Its flys in  IMC.

  

 I have a single battery  and an SD8 backup alternator and it has proven perfectly adequate.

  

 Frank



   From: owner-aeroelectric-list-server(at)matronics.com  [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of  Speedy11(at)aol.com

Sent: Friday, June 26, 2009 7:37 AM

To:  aeroelectric-list(at)matronics.com

Subject: Re:  Battery Proximity and mounting

 

  Concur 100%.

 I may remove my extra battery in the future.

 Stan Sutterfield

 Do not archive

  

  	  Quote: 	
		  Unless you have operational    features that

    encourage dual batteries, please consider    installing

    a single 17 to 18 a.h. RG battery. You can    always

    up-size later. But consider leaving 16 pounds    of

    hardware on the ground until you KNOW you need    it.

    16 extra pounds of baggage or fuel is USEFUL . . .    16

    unnecessary pounds of battery is  . . . well . .    .

    you know.



    I'm betting you'll never    need it. 	


 

  

 

  Make your summer sizzle with fast and easy  recipes for the grill.

[quote]



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

ics.com

.matronics.com/contribution



[b]

Ed Anderson

Joined: 10 Jan 2006
Posts: 475

Posted: Fri Jun 26, 2009 7:34 am Post subject: Battery Proximity and mounting

Agree.   I flew for 4 years with two Odyssey PC 680 batteries and never used the second one except for assisting to crank on a cold morning.  Finally removed the second one and have now been flying 6 years with just one battery.  I do change it out every two years and stick the old one in my lawn tractor.  

   

Ed  

     

Ed Anderson  

Rv-6A N494BW Rotary Powered  

Matthews, NC  

eanderson(at)carolina.rr.com  

http://www.andersonee.com  

http://www.dmack.net/mazda/index.html  

http://www.flyrotary.com/  

http://members.cox.net/rogersda/rotary/configs.htm#N494BW  

http://www.rotaryaviation.com/Rotorhead%20Truth.htm[/url]  

        

  

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Speedy11(at)aol.com

 Sent: Friday, June 26, 2009 10:37 AM

 To: aeroelectric-list(at)matronics.com

 Subject: Re: Battery Proximity and mounting  

  

       

Concur 100%.  

    

I may remove my extra battery in the future.  

    

Stan Sutterfield  

    

Do not archive  

    

   

   	  Quote: 	
		    

Unless you have operational features that

     encourage dual batteries, please consider installing

     a single 17 to 18 a.h. RG battery. You can always

     up-size later. But consider leaving 16 pounds of

     hardware on the ground until you KNOW you need it.

     16 extra pounds of baggage or fuel is USEFUL . . . 16

     unnecessary pounds of battery is  . . . well . . .

     you know.

 

     I'm betting you'll never need it.  	
  

    

   

    

       

  

Make your summer sizzle with [url=http://food.aol.com/grilling?ncid=emlcntusfood00000006]fast and easy recipes for the grill.  

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       [quote][b]

_________________
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jun 26, 2009 8:43 am Post subject: Battery Proximity and mounting

I have decided on Z-14 to support my electrically dependant engine because

of your second statement!  I'm not concerned with battery failure, I'm

concerned with my ability to assemble a set of components, few as they are,

that will not fail in any circumstance.



    NASA cant even do this. Why do you burden

    yourself with this goal?



The Z-14 design is more reliable

than Z-13/8 by a significant margin because all of us do not have your

capability to assemble the components.  Two battery ground connections and

two battery plus connections are a great sleeping aid to me.  I'm using

smaller batteries so the weight penalty is only a few pounds.



    Z-14? In a KR2? Can we talk about this some

    more?



    "Reliability" is generally a measure of

    component failure rates. Any component taken

    by itself can be analyzed for the purpose

    of predicting a failure rate usually expressed

    in "failures per quantity of service hours".

    For disciplines that require exceedingly high

    reliability rates we call out tested and perhaps

    even screened parts. These have demonstrated failure

    rates even if those numbers are deduced only in

    the lab.



    System reliability is another matter entirely.

    The poor pilot's definition of a reliable system

    is that which "never causes one to break a sweat."

    Systems that occasionally experience a component

    failure can still be very reliable. This is true

    when the operator doesn't find it necessary to do more

    than have the failure repaired before the next

    flight. This is what keeps FBO's in business.



    None of has enough money to craft a system with

    established reliability components. Any of us

    can craft a sweat-free system from hardware store

    components by application of simple design

    goals.



    System reliability is strongly affected by

    assembly process which is in turn influenced

    by worker skill and knowledge. You've expressed

    some concerns for your own skill levels. May

    I suggest that a minimalist failure-tolerant

    system skillfully assembled is far better than

    layers of redundancy assembled with poorly

    conceived motives or lack of understanding.



    If your concerns for understanding are properly

    founded, I'll suggest that assembling Z-14 with

    poor skills is NOT more reliable than Z-13/8

    assembled with nominal skills.



    If you were assembling this airplane on a

    deserted island with corked bottles as your

    only communications mode, your worries about

    understanding would be justified. However,

    you are a member of a society of fellow

    travelers with a huge skill-set and world

    wide verbal and visual communications network

    with nearly instant functionality.



    As a member of this List for the past 6 years

    or so, your lack of confidence for getting it

    all put together right the first time is

    curious. I'd be pleased to know how we fell

    short of addressing your need for input.



    I'll encourage you to stand back, take a

    deep breath and join us in a discussion of

    your design goals and a plan for getting

    them implemented with a minimum of cost

    weight and complexity. It would be a shame

    to burden a KR-2 with many pounds of hardware

    that steals payload and hampers performance.

    This is particularly true if the added burdens

    are no more than a band-aid on your perceptions

    of understanding. Understanding is what the

    AeroElectric-List is all about.



        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

Flagstone(at)cox.net
Guest

Posted: Fri Jun 26, 2009 9:51 am Post subject: Battery Proximity and mounting

Bob:



A complete non answer.  Lot of words...no relevance.



On page 17-11 (rev11) you state that "RG battery reliability and performance 

supplemented with good preventative maintenance drives probability of gross 

battery failure to zero"



You don't say "near zero", "close to zero", "approaching zero", or any such 

thing.  To claim anything has a zero probability of failure is a pretty bold 

statement to make.  Further,  judging from the general tone of your writing 

style, there's as much a chance of  that statement being rhetoric as 

anything else.



When I first read your book a couple years ago,  I tried to get some 

clarification from you on that statement.  At first, when I asked directly, 

you simply didn't address the question.  I gave up on that approach.   Since 

then, whenever other group members have touched on the issue, I have 

attempted, by asking questions in different ways, to get  you to explain 

further the meaning of your statement.  In response to the inquiries (mine 

and others) on this subject, you either:

    1.  Don't answer.

    2.  Provide theoretical fluffery

    3.  Answer questions that aren't asked

    4.  Introduce extraneous issues

    5.  Claim its beyond understanding



At first, I thought I was close to getting some answers this time, but as 

before, the answers degraded into one or more of the above categories.  I 

really don't understand why you can't give a full and complete explanation 

of what you mean by "gross battery failure" and "zero probability" in some 

meaningful and understandable way.  After all, its your statement, you 

should be able to substantiate it.  But, that's apparently not the case. 

I've noticed that you seem to follow that pattern on a few other issues as 

well.   Anyway, I'm tired of  trying to coax an explanation out of you so I 

won't bring up it up again.  I'll just assume the statement was the result 

of your writing style and not to be taken literally.  In any regard,  I 

don't need the information now, and when I do,  I'll get it from other 

sources.

Thanks

---

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