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A Tale of Two Batteries

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bicyclop(at)pacbell.net
Guest

Posted: Fri Sep 26, 2008 2:29 pm Post subject: A Tale of Two Batteries

Howdy,



I recently bought the West Mountain Radio CBA and did some tests on some 

old batteries. Here's what I found:



Battery 1 came with our airplane and after about 2 years we decided to 

replace it. It is a Conorde RG-25XC rated at 25 ah. It was removed from 

the airplane in January of 06 and charged 2 or 3 times since. It mostly 

just sat. I charged it with a BatteryMINDer at 8 amps and discharged it 

at 4amps to 10.5v. It tested to 12.1 ah, or about half it's rated capacity.



Battery 2 is the same make and model and is the battery which replaced 

Bat 1 in Jan/06. This battery gave no problems in service until the day 

that the positive cable chafed through and shorted against a stainless 

braided brake line in flight. It resulted in a smoke filled cabin and an 

emergency landing (on airport). When I arrived on the scene an hour and 

a half later, I moved the brake line away from the cable and measured 5 

volts on the battery. Needless to say, the cable has been protected from 

this ever happening again. The battery was charged overnight (on an 

ancient non-smart charger) and returned to service. A month or two 

later, it failed to start the airplane and was changed out for another 

RG-25 XC. This was all about a year ago. I don't remember if I charged 

this battery after removal, but it was at 12.66 volts before I charged 

it for this test. I discharged it at 4 amps to 10.5v. It, surprisingly, 

came in at 25.4 ah - right at rated capacity. I'm going to swap it back 

into the airplane long enough to test Battery 3 and see how that one is 

doing.



I also tested a friend's 35 ah Concorde battery which is a year old but 

hasn't yet seen service at 4 amps to 10.5v and got 37.4 ah out of it.



In the meantime, my computer's UPS quit working so I pulled the 8 ah 

battery out of it and found it to be 5.3v. I extended the leads out of 

the UPS box and hooked them to Battery 1 and hooked my computer back up 

to it. The float voltage seems high at 13.72, but I'm not worried about 

it seeing as how that battery is useless for much else and if it fails 

at some point, I have another to replace it.



Hope I didn't bore Y'all too much,



Ed Holyoke

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nuckolls.bob(at)cox.net
Guest

Posted: Sat Sep 27, 2008 5:29 am Post subject: A Tale of Two Batteries

At 03:27 PM 9/26/2008 -0700, you wrote:

 	  Quote: 	
		  



Howdy,



I recently bought the West Mountain Radio CBA and did some tests on some 

old batteries. Here's what I found:


	


    <snip>



 	  Quote: 	
		  Hope I didn't bore Y'all too much,



Ed Holyoke


	


    Ed, thank you for sharing this with us. And

    congratulations on your decision to expand your

    toolbox for understanding.



    I've listened to and read a lot of conversation

    about battery condition and performance where the

    participants formulated hypotheses based on conjecture

    . . . and then acted on those hypotheses (or advised

    others to act on those hypotheses) in what was

    mostly a waste of $time$.



    Your willingness to replace conjecture with data and

    understanding will serve you well . . . your

    encouragement of others to do likewise will serve

    them well.



    As a side note, there are tests conducted on deliberately

    abused batteries to demonstrate an ability to recover from

    that abuse. I don't recall the specifics but they involved

    taking a battery down to 0 capacity for a long period of

    time and then cycling it through a series of charge and

    discharge protocols while measuring the useful capacity

    of the battery during each discharge. All of Concorde's

    products are qualified to these requirements as are

    Hawker's aircraft products.



    I've seen quantities of $high$ batteries sitting in Concorde's

    warranty return pile where the techs reported successful

    recovery of a substantial number of the returns. Some had

    be discharged and out of service for months. I don't

    recall the figures but somewhere around 1/3 were

    recoverable to 80% or better capacity.



    This data suggests that many batteries are returned

    for warranty not because they are defective. They

    came back because the user (or his mechanic) didn't understand

    how ingredients that go into the recipe for success

    in aircraft power generation and storage systems

    worked together.



    Batteries are secretive buggers. There are no dials,

    no diagnostic ports, and a host of vulnerabilities

    to optimized performance. Without tools of investigation

    and maintenance, the user is playing the odds that

    don't get any better by being ignorant.



    As you've discovered, it takes $time$ and $investment$

    to achieve your level of understanding. Most airplane

    owners are not compelled to make such expenditures. That's

    why I've often recommend that folks buy the least

    expensive battery and replace it every year. This

    protocol may well provide a superior system reliability

    with a minimum cost of ownership.



    It's that CBA a slick tool?  By the way, you can use

    it also as a data acquisition system. If you'd like to

    measure and plot a voltage over a long period of time,

    set it up to "test" a battery with 0.01A of discharge

    rate. If this level of load is so small that it doesn't

    adversely affect your system under investigation, then

    the software will dutifully march off and gather the

    data for you and put it out in nice plots. I own

    two of those critters.



    Bob . . .

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bicyclop(at)pacbell.net
Guest

Posted: Sat Sep 27, 2008 11:16 pm Post subject: A Tale of Two Batteries

Howdy Bob,



I'd be interested to find out what the protocols are for salvaging 

damaged batteries. Got nothing to lose, after all. I guess I'll poke 

around the Concorde site and see if I can dig anything up.



I was going to build the test rig you wrote about long ago with the 

electric clock and the zener diode cutout circuit, but I never go around 

to it and, when I read about the CBA, I thought "That's what I really 

want". It is a much more sophisticated and capable tool.



On another note, is the VDC battery minder - aviation adjusted that much 

better than the standard 12248 charger which can be had about $65 

cheaper? What is the AA, just a tenth of an amp or so lower setting, or 

is it magic?



Pax,



Ed Holyoke

 	  Quote: 	
		  

    As a side note, there are tests conducted on deliberately

    abused batteries to demonstrate an ability to recover from

    that abuse. I don't recall the specifics but they involved

    taking a battery down to 0 capacity for a long period of

    time and then cycling it through a series of charge and

    discharge protocols while measuring the useful capacity

    of the battery during each discharge. All of Concorde's

    products are qualified to these requirements as are

    Hawker's aircraft products.



    I've seen quantities of $high$ batteries sitting in Concorde's

    warranty return pile where the techs reported successful

    recovery of a substantial number of the returns. Some had

    be discharged and out of service for months. I don't

    recall the figures but somewhere around 1/3 were

    recoverable to 80% or better capacity.



    This data suggests that many batteries are returned

    for warranty not because they are defective. They

    came back because the user (or his mechanic) didn't understand

    how ingredients that go into the recipe for success

    in aircraft power generation and storage systems

    worked together.



    Batteries are secretive buggers. There are no dials,

    no diagnostic ports, and a host of vulnerabilities

    to optimized performance. Without tools of investigation

    and maintenance, the user is playing the odds that

    don't get any better by being ignorant.



    As you've discovered, it takes $time$ and $investment$

    to achieve your level of understanding. Most airplane

    owners are not compelled to make such expenditures. That's

    why I've often recommend that folks buy the least

    expensive battery and replace it every year. This

    protocol may well provide a superior system reliability

    with a minimum cost of ownership.



    It's that CBA a slick tool?  By the way, you can use

    it also as a data acquisition system. If you'd like to

    measure and plot a voltage over a long period of time,

    set it up to "test" a battery with 0.01A of discharge

    rate. If this level of load is so small that it doesn't

    adversely affect your system under investigation, then

    the software will dutifully march off and gather the

    data for you and put it out in nice plots. I own

    two of those critters.



    Bob . . .

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nuckolls.bob(at)cox.net
Guest

Posted: Sun Sep 28, 2008 8:29 am Post subject: A Tale of Two Batteries

At 12:15 AM 9/28/2008 -0700, you wrote:

 	  Quote: 	
		  



Howdy Bob,



I'd be interested to find out what the protocols are for salvaging damaged 

batteries. Got nothing to lose, after all. I guess I'll poke around the 

Concorde site and see if I can dig anything up.


	


     I may have the process document someplace. If I can't

     find it, I can get it from Concorde. It's not

     "magic". It doesn't use any form of incantation like

     de-sulfation pulsers, etc.



     As I recall it starts with a controlled over-charge

     that pushes the terminal voltage pretty high until

     internal resistance to come down. I think I recall

     Skip talking about 20 volts or more on a 12v battery.



     After the battery demonstrates a willingness to draw

     current in a more typical recharge mode, the battery

     is subjected to a series of constant current, charge-

     discharge cycles with each discharge cycle being quantified

     for energy delivered. Early in the process, successive

     discharges grow stronger.



     After the ability to store energy flattens out, the

     battery may be either deemed serviceable or ready for

     re-cycling. This process won't "refurbish" a worn out

     battery but it may "wake up" a mis-treated battery.

 	  Quote: 	
		  I was going to build the test rig you wrote about long ago with the 

electric clock and the zener diode cutout circuit, but I never go around 

to it and, when I read about the CBA, I thought "That's what I really 

want". It is a much more sophisticated and capable tool.


	


     Yup, in this business tools is what it's all about.

     No matter how much you understand, you're not going

     to drive that nail without at least a hammer. Without

     the hammer, you're skill-set remains un-quantified

     and un-demonstrated.

 	  Quote: 	
		  On another note, is the VDC battery minder - aviation adjusted that much 

better than the standard 12248 charger which can be had about $65 cheaper?


	


     ALL of the smart chargers that do constant current, voltage

     limited charging, top-off followed by a maintenance

     mode are about 1000 light years ahead of any "trickle-

     charger" of yesteryear. Like this:



http://www.aeroelectric.com/Pictures/Curves/Ideal_Recharge_Protocol.jpg



     Now, here's the measured performance on a variety of

     "smart chargers" . . .



http://www.aeroelectric.com/Pictures/Curves/Battery_Minder_Recharge.pdf



http://www.aeroelectric.com/Pictures/Curves/Battery_Tender_Recharge.pdf



http://aeroelectric.com/Pictures/Battery_Chargers/Schumacher_Chargers/SC2500-50AH.jpg



http://www.aeroelectric.com/Pictures/Curves/HF93258_1.jpg



http://www.aeroelectric.com/Pictures/Curves/schumacher_2.jpg



http://www.aeroelectric.com/Pictures/Curves/schumacher_3.jpg



http://www.aeroelectric.com/Pictures/Curves/schumacher_5.jpg



     None of these charge/maintenance protocols are identical

     to another one. Some don't exactly capture the "Idealized

     Protocol". Nonetheless, every guy behind the counter

     in a booth at OSH will point to HIS recharge curve and compare

     it with the recharge curve for the charger being sold across

     the isle and do his best to convince you that HIS is better.



     This is sort of like water districts of various cities

     extolling the virtues of THEIR water treatment by

     taking swipes at each other. They ignore the fact

     that only in the last 100 years or so of mankind's

     existence on the planet has the threat of water-borne

     disease become non-existent because of our understanding

     of simple-ideas that have nothing to do with hardness,

     taste, or perhaps even clarity of the product.



     And so it is with battery chargers. They're all so good

     compared to what we had 20 years ago that the only thing

     they can do is snipe at each other!

 	  Quote: 	
		    What is the AA, just a tenth of an amp or so lower setting, or is it magic?


	




     Not sure about what you're asking. Are you wondering what

     test currents are appropriate for testing AA cells?



     Depends on the technology. We know that the higher the

     load, the lower the apparent capacity due to internal losses

     in the cell.  The discharge current selected for testing

     purposes has to do with the application in which you choose

     to use the product. For example, a wrist watch runs on fractions

     of microamps so you can get most of the energy out of that

     itty-bitty button cell in spite of it's 'horrendous' internal

     impedance. On the other hand, my digital camera with the big

     LCD color screen needs 500 mA or more of supply current.

     In this case, performance is optimized by selecting cells

     with the lowest practical resistance which is not necessarily

     the cell with the greatest capacity.



     I did all the tests on alkaline cells with 5 ohm load



http://www.aeroelectric.com/articles/AA_Bat_Test.pdf



     . . . which was in the ball-park for various applications

     and consistent from test to test so that the brands could

     be compared.



     This suite of tests was run on AA cells at 300 mA constant

     current:



http://www.aeroelectric.com/Pictures/Curves/AA_Battery_Tests_80322.jpg



     Again, the current needed to be consistent from test to test

     and in the ball-park for the applications (digital cameras).



     However, if you ran this same array of cells at say, 20 mA

     discharge rates, you'd get a LOT more total energy out of them.



     Bob . . .

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bicyclop(at)pacbell.net
Guest

Posted: Sun Sep 28, 2008 11:08 am Post subject: A Tale of Two Batteries

Bob,

What I was asking about was the VDC 12248-AA-1 charger as compared to 

the straight 12248. I think the "aviation adjusted" charger runs a 

couple of tenths of a volt (I misspoke when I said amp) lower to make 

Concorde and Gill happy. I was asking if it really makes much difference 

in the life of the battery - $65 worth. I'm guessing from your test 

curves and stuff that the answer is probably no. The 12248 will also do 

flooded batteries where the AA-1 is AGM only.

Pax,

Ed Holyoke

Robert L. Nuckolls, III wrote:

 	  Quote: 	

>  What is the AA, just a tenth of an amp or so lower setting, or is it 

> magic?

     Not sure about what you're asking. Are you wondering what

     test currents are appropriate for testing AA cells?

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nuckolls.bob(at)cox.net
Guest

Posted: Sun Sep 28, 2008 5:25 pm Post subject: A Tale of Two Batteries

At 12:01 PM 9/28/2008 -0700, you wrote:

 	  Quote: 	
		  



Bob,



What I was asking about was the VDC 12248-AA-1 charger as compared to the 

straight 12248. I think the "aviation adjusted" charger runs a couple of 

tenths of a volt (I misspoke when I said amp) lower to make Concorde and 

Gill happy. I was asking if it really makes much difference in the life of 

the battery - $65 worth. I'm guessing from your test curves and stuff that 

the answer is probably no. The 12248 will also do flooded batteries where 

the AA-1 is AGM only.


	


    Aha! I'm not familiar with those chargers . . . but yes,

    a few tenths here, a few tenths there is probably

    not significant in the grand scheme of things. I'd like

    to know the definition of "aviation adjusted" . . .

    and the rationale for making the distinction.



    Bottom line is that NO AIRPLANE in service even approximates

    the fondest wishes of a manufacturer for the care and feeding

    of their particular baby. So if you've got a top-off charger

    that drops down to within a half a volt of open circuit

    voltage, it's just fine.



    Bob . . .

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bicyclop(at)pacbell.net
Guest

Posted: Tue Sep 30, 2008 10:37 am Post subject: A Tale of Two Batteries

Follow up:



I tested Battery 3 yesterday and quit at 11volts instead of 10.5 because 

it had already proved itself and I wanted to get it on the charger 

before I left the hangar. It tested to 25.4 ah at a 4 amp draw (and 

stopping early). I have no doubt that it would last longer than my fuel 

after an alternator failure. Displayed on the same graph as Battery 2, 

it looks better, but only slightly. By the way, I looked closer and 

these batteries are rated at 24 ah, not 25.



I think we'll probably set 16 or 17 amp hours as the bottom limit, test 

at annual and run this battery for a long, long time to come. It might 

take a while to pay for the CBA in un-replaced batteries, but the 

knowledge of just how much is in there is priceless.



Pax,



Ed Holyoke



Ed Holyoke wrote:

 	  Quote: 	
		   

 <bicyclop(at)pacbell.net>



 Howdy,



 I recently bought the West Mountain Radio CBA and did some tests on 

 some old batteries. Here's what I found:



 Battery 1 came with our airplane and after about 2 years we decided to 

 replace it. It is a Conorde RG-25XC rated at 25 ah. It was removed 

 from the airplane in January of 06 and charged 2 or 3 times since. It 

 mostly just sat. I charged it with a BatteryMINDer at 8 amps and 

 discharged it at 4amps to 10.5v. It tested to 12.1 ah, or about half 

 it's rated capacity.



 Battery 2 is the same make and model and is the battery which replaced 

 Bat 1 in Jan/06. This battery gave no problems in service until the 

 day that the positive cable chafed through and shorted against a 

 stainless braided brake line in flight. It resulted in a smoke filled 

 cabin and an emergency landing (on airport). When I arrived on the 

 scene an hour and a half later, I moved the brake line away from the 

 cable and measured 5 volts on the battery. Needless to say, the cable 

 has been protected from this ever happening again. The battery was 

 charged overnight (on an ancient non-smart charger) and returned to 

 service. A month or two later, it failed to start the airplane and was 

 changed out for another RG-25 XC. This was all about a year ago. I 

 don't remember if I charged this battery after removal, but it was at 

 12.66 volts before I charged it for this test. I discharged it at 4 

 amps to 10.5v. It, surprisingly, came in at 25.4 ah - right at rated 

 capacity. I'm going to swap it back into the airplane long enough to 

 test Battery 3 and see how that one is doing.



 I also tested a friend's 35 ah Concorde battery which is a year old 

 but hasn't yet seen service at 4 amps to 10.5v and got 37.4 ah out of it.



 In the meantime, my computer's UPS quit working so I pulled the 8 ah 

 battery out of it and found it to be 5.3v. I extended the leads out of 

 the UPS box and hooked them to Battery 1 and hooked my computer back 

 up to it. The float voltage seems high at 13.72, but I'm not worried 

 about it seeing as how that battery is useless for much else and if it 

 fails at some point, I have another to replace it.



 Hope I didn't bore Y'all too much,



 Ed Holyoke

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