Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

battery chargers

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

icubob(at)gmail.com
Guest

Posted: Thu Mar 01, 2012 8:32 am Post subject: battery chargers

hi bob,

 saw a wedsite for ''aci'' battery chargers/tenders. are they really better?  it does seem that sometimes my schumacher tender doesn't keep my odessey 620 fully charged.

             bob noffs

  [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Mar 01, 2012 3:01 pm Post subject: battery chargers

At 10:30 AM 3/1/2012, you wrote:

 	  Quote: 	
		  hi bob,

  saw a wedsite for ''aci'' battery chargers/tenders. are they 

 really better?  it does seem that sometimes my schumacher tender 

 doesn't keep my odessey 620 fully charged.

             bob noffs


	


    Can't tell you . . . I have no data either anecdotally

    or measured to say that one is 'better' than the other.



    Which model Schumacher are you using? Did it ever work?

    When you put a voltmeter on a stored battery (charging

    has been done for a day or two, what do you read?



    I monitored the performance of a Schumacher 1562 (now

    obsolete) a few years ago and got a righteous plot



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



    Without doing a similar exercise on your particular

    charger, I'm unable to offer any judgement about its

    condition. What makes you think it's not keeping

    the 620 charged. It's possible that the charger is fine

    and the battery's capacity has degraded.



    If you do replace your Schumacher charger, you can send

    it to me and I'll have it stroke a dead battery to see

    if it's working right.



   Bob . . .

ralphmariafinch(at)gmail.
Guest

Posted: Thu Mar 01, 2012 3:31 pm Post subject: battery chargers

Aviation Consumer, October 2011, reviewed battery chargers and their

headline said:



Battery Chargers: VDC in a Walk

VDC makes the only low-cost aviation-specific charger and using it can

extend battery life by months. There are several models to pick from.



They have a charger specific to the Odessey:

http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-Specific-12-Volt-8A-Odyssey-Speci-p-16168.html



On Thu, Mar 1, 2012 at 8:30 AM, bob noffs <icubob(at)gmail.com> wrote:

 	  Quote: 	
		   hi bob,

  saw a wedsite for ''aci'' battery chargers/tenders. are they really

 better?  it does seem that sometimes my schumacher tender doesn't keep my

 odessey 620 fully charged.

             bob noffs

icubob(at)gmail.com
Guest

Posted: Thu Mar 01, 2012 4:25 pm Post subject: battery chargers

hi bob, i have had the schumacher 1562[?] on my 620 every day of the battery's life. plane only first flew last fall so battery has not gotten much use but it is at least 5 yrs old. charging is usually not an issue but twice battery would not crank engine on initial start up. i was going to have the battery load tested but then it functioned fine so the feeling went away. strange but it only took 20-30 minutes to bring the battery up to full charge with a 12 AMP CHARGER. anyway, i don't mean to imply i have a problem i am looking for answers to. i was curious about this ''new'' charger as they more or less stated that fiberglass mat batteries require a different type of maintainer. these new chargers have starting amps of 1,3, or 7 amps and taper down from there. was wondering if conditions might stop a schumacher from getting battery to full charge? i usually see 14 volts when i think to check it. i couldn't say what voltage was on the 2 occasions it wouldn't turn over the engine.

            bob noffs

On Thu, Mar 1, 2012 at 5:30 PM, Ralph Finch <ralphmariafinch(at)gmail.com (ralphmariafinch(at)gmail.com)> wrote:

 [quote]--> AeroElectric-List message posted by: Ralph Finch <ralphmariafinch(at)gmail.com (ralphmariafinch(at)gmail.com)>

 Aviation Consumer, October 2011, reviewed battery chargers and their

 headline said:

 Battery Chargers: VDC in a Walk

 VDC makes the only low-cost aviation-specific charger and using it can

 extend battery life by months. There are several models to pick from.

 They have a charger specific to the Odessey:

 http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-Specific-12-Volt-8A-Odyssey-Speci-p-16168.html

 On Thu, Mar 1, 2012 at 8:30 AM, bob noffs <icubob(at)gmail.com (icubob(at)gmail.com)> wrote:

 > hi bob,

 >  saw a wedsite for ''aci'' battery chargers/tenders. are they really

 > better?  it does seem that sometimes my schumacher tender doesn't keep my

 > odessey 620 fully charged.

 >             bob noffs

 ========================

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

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

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

 ===========

[b]

nuckolls.bob(at)aeroelect
Guest

Posted: Thu Mar 01, 2012 8:46 pm Post subject: battery chargers

At 06:23 PM 3/1/2012, you wrote:

hi bob, i have had the schumacher 1562[?] on my 620 every day of the 

battery's life. plane only first flew last fall so battery has not 

gotten much use but it is at least 5 yrs old. charging is usually not 

an issue but twice battery would not crank engine on initial start up.



    Any time the battery wont crank the engine after

    sitting on a maintainer for any length of time,

    The charger, the battery or both are suspect.



i was going to have the battery load tested but then it functioned 

fine so the feeling went away. strange but it only took 20-30 minutes 

to bring the battery up to full charge with a 12 AMP CHARGER.



    Which suggests that the battery is down to 6 a.h. or so.



Anyway, i don't mean to imply i have a problem i am looking for 

answers to. i was curious about this ''new'' charger as they more or 

less stated that fiberglass mat batteries require a different type of 

maintainer.



    Not true . . .



These new chargers have starting amps of 1,3, or 7 amps and taper 

down from there. was wondering if conditions might stop a schumacher 

from getting battery to full charge?



    If it's a real charger/maintainer and features a top-off

    cycle of 14.5 volts or more, then any size charger will

    bring any size battery up to snuff. It's just a matter of

    time.



    My portable power batteries (50AH and 32 AH in parallel)

    have been  brought up on a 0.7A Battery Tender. The light

    may stay red for a couple of days but it eventually

    gets the job done.



I usually see 14 volts when i think to check it. i couldn't say what 

voltage was on the 2 occasions it wouldn't turn over the engine.



    Suggest you do a cap-check on the battery. What

    you've related thus far suggests the battery

    is not airworthy.

   Bob . . .

Hopperdhh(at)aol.com
Guest

Posted: Sat Mar 03, 2012 9:10 am Post subject: battery chargers

It would have to extend it by a lot of months to pay for itself.   My last PC680 lasted 5 years without any help from a battery tender.  That  includes sitting for 3 or 4 weeks at a time during the Indiana winters with no  charger at all.  I finally replaced it even though it was still cranking my  IO-360 fine, even on some hot starts that took 15 or 20 seconds.  I  was starting to worry that the vibration could be getting to it.  I didn't  want it to blow up!!

  

 You could buy another battery for less than the price of the battery  tender.  Am I missing something here?

  

 Dan

 RV-7A - N766DH - flying 7 years

  

  

  In a message dated 3/1/2012 6:32:40 P.M. Eastern Standard Time,  ralphmariafinch(at)gmail.com writes:

  	  Quote: 	
		  -->    AeroElectric-List message posted by: Ralph Finch    <ralphmariafinch(at)gmail.com>



Aviation Consumer, October 2011,    reviewed battery chargers and their

headline said:



Battery Chargers:    VDC in a Walk

VDC makes the only low-cost aviation-specific charger and    using it can

extend battery life by months. There are several models to    pick from.



They have a charger specific to the    Odessey:

http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-Aviation-Specific-12-Volt-8A-Odyssey-Speci-p-16168.html



On    Thu, Mar 1, 2012 at 8:30 AM, bob noffs <icubob(at)gmail.com> wrote:

 	  Quote: 	
		      hi bob,

  saw a wedsite for ''aci'' battery chargers/tenders. are    they really

 better?  it does seem that sometimes my schumacher    tender doesn't keep my

 odessey 620 fully charged.

                bob  = Use  ilities  ay                 - MATRONICS WEB FORUMS               - List Contribution Web Site  p;                             


	




	


 [quote][b]

skywagon

Joined: 11 Feb 2006
Posts: 184

Posted: Sat Mar 03, 2012 9:37 am Post subject: battery chargers

Dan,

 Many battery "maintainers/tenders" are well under $25 and do a  very good job.  That is certainly less than the cost of a new Gill or  Concorde.

 David

  

   

 [quote]   ---

icubob(at)gmail.com
Guest

Posted: Sat Mar 03, 2012 9:39 am Post subject: battery chargers

thanks bob, as the prop was sent out to be shortened i guess no time like the present to pull the battery and get a load test done.

  bob noffs

 On Thu, Mar 1, 2012 at 10:42 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

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



  At 06:23 PM 3/1/2012, you wrote:

hi bob, i have had the schumacher 1562[?] on my 620 every day of the battery's life. plane only first flew last fall so battery has not gotten much use but it is at least 5 yrs old. charging is usually not an issue but twice battery would not crank engine on initial start up.

 



  Any time the battery wont crank the engine after

  sitting on a maintainer for any length of time,

  The charger, the battery or both are suspect.  



i was going to have the battery load tested but then it functioned fine so the feeling went away. strange but it only took 20-30 minutes to bring the battery up to full charge with a 12 AMP CHARGER.

 



  Which suggests that the battery is down to 6 a.h. or so.  



Anyway, i don't mean to imply i have a problem i am looking for answers to. i was curious about this ''new'' charger as they more or less stated that fiberglass mat batteries require a different type of maintainer.

 



  Not true . . .  



These new chargers have starting amps of 1,3, or 7 amps and taper down from there. was wondering if conditions might stop a schumacher from getting battery to full charge?

  If it's a real charger/maintainer and features a top-off

   cycle of 14.5 volts or more, then any size charger will

  bring any size battery up to snuff. It's just a matter of

  time.



  My portable power batteries (50AH and 32 AH in parallel)

  have been  brought up on a 0.7A Battery Tender. The light

   may stay red for a couple of days but it eventually

  gets the job done.  



I usually see 14 volts when i think to check it. i couldn't say what voltage was on the 2 occasions it wouldn't turn over the engine.

  Suggest you do a cap-check on the battery. What

   you've related thus far suggests the battery

  is not airworthy.

 Bob . . . 

  

 ===========================================

_ities such as List Un/Subscription,

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

 ======================ttp://forums.matronics.com/" target="_blank">http://forums.matronics.com

 ======================       -Matt Dralle, List Admin.

 ================================



 



[b]

Hopperdhh(at)aol.com
Guest

Posted: Sat Mar 03, 2012 10:30 am Post subject: battery chargers

Hi David,

  

 I agree with you on the type of battery you mention.  Although, I  don't know anything about a $15 tender.  If the electrolyte level gets low  you can have an explosion.  How do I know that?!!

  

 The tender in the link costs about $200 and is specific to the  Odyssey.  The Odyssey has a very slow self discharge rate compared to wet  batteries, and shouldn't need to be charged unless there is a constant load of  some kind on it.  My plane doesn't have anything drawing current when it is  off.

  

 Dan

  

  

  In a message dated 3/3/2012 12:38:19 P.M. Eastern Standard Time,  skywagon(at)charter.net writes:

 [quote]   Dan,

   Many battery "maintainers/tenders" are well under $25 and do    a very good job.  That is certainly less than the cost of a new Gill or    Concorde.

   David

    

         

   [quote]     ---

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Mar 03, 2012 10:42 am Post subject: battery chargers

At 11:38 AM 3/3/2012, you wrote:

  	  Quote: 	
		  thanks bob, as the prop was sent out to be shortened i guess no time like the present to pull the battery and get a load test done. 	


    LOAD and CAPACITY. That's one of the characteristics of

    SLVA batteries that tends to convince us they are

    flightworthy when in fact, they may not be.



    Their internal impedance is so much lower than a

    flooded battery that their capacity might well have

    dropped below your design goals for battery-only

    operations and still get the engine started.



    One of our members just completed the 'po boy's

    cap checker described here:



 [img]cid:.0[/img]



    After you've LOAD tested a battery to see what current it

    will deliver when loaded down to 9v for 15 seconds, you

    recharge it and put this fixture on it, set the clock for

    noon (or midnight) and push the button. The relay will

    pull in and light the lamp thus placing about a 4A load

    on the battery. Adjust the number and size of lamps in

    parallel to get a load that approximates your alternator-out

    loads.



    When the relay drops, the clock stops and you've got a 

    benchmark for how well the battery will support your

    electro-whizzies with a failed alternator. Batteries

    are mostly replaced in the heavy GA iron because they

    won't power the goodies . . . not because they won't

    start the engine.



 



 

   Bob . . .

969baa.jpg

Description:

Filesize:

91.05 KB

Viewed:

7484 Time(s)

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Mar 03, 2012 3:24 pm Post subject: battery chargers

At 12:29 PM 3/3/2012, you wrote:

 Hi David,

  

 I agree with you on the type of battery you mention.  Although, I don't know anything about a $15 tender.  If the electrolyte level gets low you can have an explosion.  How do I know that?!!



    Let us consider the Odyssey Technical Manual which

    may be downloaded from:



  http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf

  

    First, I searched for the word "explosion" and didn't find

    it. 



    Next I searched for the word "damage" and I find it

    5 times. The word is used 4 times in the context of

    mechanical damage to the battery or damage to surroundings

    due to leakage. 



    The 5th time is used on page 13 in the context of discussing

    deep discharge recovery processes. Techniques that may be

    successful in recovering a battery that has been BADLY

    DISCHARGED without benefit of a timely recharge.



 

 The tender in the link costs about $200 and is specific to the Odyssey.  The Odyssey has a very slow self discharge rate compared to wet batteries, and shouldn't need to be charged unless there is a constant load of some kind on it.



    Or it was put away in a discharged state . . . like you've

    just spent the afternoon trolling, mowing the yard with

    a DC electric lawn mower, etc. etc. In situations where

    the battery is used to supply a major portion of it's

    rated capacity on each discharge cycle, then recharging it

    in a gentle, prescribed manner may be of some benefit

    to service life. But consider the use in most automotive

    applications including aircraft. You use 2 to 5% off the

    top to get the engine started. Then the alternator stuffs

    the energy back in at a prodigious rate set by what ever

    the alternator supplies over and above the vehicle's

    requirements.



    After some period of operation, the battery is soon topped

    of and presumably remains so until the next time the

    battery master is flipped on during pre-flight. It' is

    quite possible . . . nay probable that all batteries aboard

    airplanes are never ministered to by precision chargers . . .

    further, it's not clear how a battery would benefit from

    attendance by a precision charger if you DID have AC

    in the hangar and plugged the airplane in until the next

    flight. The particularly robust nature of the AGM battery

    was cited by another reader who offered:



 It would have to extend it by a lot of months to pay for itself.  My last PC680 lasted 5 years without any help from a battery tender.  That includes sitting for 3 or 4 weeks at a time during the Indiana winters with no charger at all.  I finally replaced it even though it was still cranking my IO-360 fine, even on some hot starts that took 15 or 20 seconds.  I was starting to worry that the vibration could be getting to it.  I didn't want it to blow up!!

  

 You could buy another battery for less than the price of the battery tender.  Am I missing something here?



    Concerns for blowing up AGM batteries have no foundation

    in physics of design or fact of service. The majority

    of liberated oxygen and hydrogen gasses never get out of

    the mats else they would not be available for recombination.



    I would encourage interested readers to compare the recommended

    3-step charge profiles for AGM batteries. By the way, the

    Odyssey is but one of MANY AGM products all of which will

    benefit from the same sort of (Step 1) CC charge, (Step 2)

    CV top-off, (Step 3) CV sustenance at just over the open-circuit

    terminal voltage so as to offset self-discharge currents.



    The product literature shown at



  http://tinyurl.com/745n3tr 



    gives rise to a number of questions.



    (1) Exactly what is  meant by "aviation specific"?

    The percentage of batteries used in airplanes compared

    to all other applications is a spit in the ocean.

    Exactly what makes the battery worthy of $200 chargers

    just because it's bolted to an airplane?



    (2) Then there is the "Odyssey specific" thing. I spent

    a day touring the Enersys facilities in Mexico, MO a

    few years back. Got to walk through the highly automated

    factory and spend several hours in a conference room drinking

    their sodas while a bevy of engineers and marketing people

    assured me and my colleagues that the Enersys products were

    drop-in replacements for Gill, Concorde, Rebatt . . . you

    name it. Not one individual mentioned anything about special

    considerations for Enersys products bolted to airplanes or

    chargers necessary to maximize service life of an Odyssey

    product.



    In fact, aside from their 'pure lead' plates and highly

    automated manufacturing processes, there were no claims

    to fame other than absolute quality in comparison with

    other AGM products . . . no special treatments expected.



    (3) Then there's that "desulfator-conditioner" thing.

    Skipp Koss and I have discussed the marketing hype

    phenomenon surrounding so-called desulfation techniques.

    A battery that is badly discharged and allowed to sit

    will indeed suffer from the effects of large crystal

    formation that degrades the battery's performance. The

    deep discharge recovery techniques described in the Odyssey

    manual cited above are about word for word equal to the

    techniques described by Concorde (and I presume others).

    The "aviation specific" device described does not claim

    to conform with those recovery techniques. The word "sulfate"

    is not mentioned in any context in the Odyssey manual. 



    Wikipedia speaks rather well to the sulfation process

    here: 



  http://en.wikipedia.org/wiki/Desulfation#Sulfation_and_desulfation

 

    But in particular, consider these statements . . .



 "Sulfation can be avoided if the battery is fully recharged immediately after a discharge cycle."



    and this one . . .



 SLI batteries (starting, lighting, ignition; i.e. car batteries) have less deterioration because they are used more frequently vs deep cycle batteries. Deep cycle batteries tend to require more desulfation, can suffer from overcharging, and can be in a very large bank which leads to unequal charging and discharging.



    As discussed earlier, it's a design goal to (1) use very

    little of the battery's capacity to star the engine

    followed by (2) a recharge event whereupon the battery is 

    (3) held in a high state of charge as a reserve source

    of energy in the event of alternator failure.



    In this type of service, the battery can be expected to

    perform for hundreds of flight cycles as long as the

    battery is not put away in a degraded state of charge.



    (4) Then there's the guarantee:



 "We guarantee to significantly increase both your battery's life and performance

 or we will refund 100% of your money within one (1) full year. This is in

 addition to our five (5) year "no hassle" warranty."



    Not sure what all that means . . . but exactly how

    is John Q Public pilot supposed to make a quantitative

    evaluation the this charger's performance as he chooses

    to use it on his airplane? Without having laboratory

    grade data on batteries that failed too soon to compare

    with batteries blessed with their "aviation specific" charger,

    how would the dissatisfied consumer have a basis for

    complaint?



    (5) Then there's this notion that the battery being

    put away in the hangar is suffering from any state of

    discharge that calls for a kinder-gentler-precision

    recharge.



    (6) Finally, there's a statement in the Odyssey manual

    to the effect . . .



 "Small, portable automotive and powersport chargers may also be used to charge your ODYSSEY battery. These chargers are generally designed to bring a discharged battery to a state of charge (SOC) that is high enough to crank an engine. Once the engine is successfully cranked, its alternator should fully charge the battery. It is important to keep in mind the design limitations of these small chargers when using them."



    and this. . .



 "All ODYSSEY batteries can be quickly charged. The graph below shows their exceptional fast charge characteristics at a constant 14.7V for three levels of inrush current. These current levels are similar to the output currents of modern automotive alternators. Table 6 and Figure 7 show the capacity returned as a function of the magnitude of the inrush current."



 "Standard internal combustion engine alternators with an output voltage of 14.2V can also charge these batteries. The inrush current does not need to be limited under constant voltage charge. However, because the typical alternator voltage is only 14.2V instead of 14.7V, the charge times will be longer than those shown in Table 5."



    and finally this . . .



 "Another class of chargers is designed specifically to maintain a battery in a high SOC. These chargers, normally in the 3/4 amp to 11/2 amp range, are not big enough to charge a deeply discharged ODYSSEY® battery. They must only be used either to continuously compensate for parasitic losses or to maintain a trickle charge on a stored battery, as long as the correct voltages are applied. It is very important, therefore, to ensure that the ODYSSEY battery is fully charged before this type of charger is connected to it."



     From Odyssey's own literature, we find that their

     batteries can be charged under a host of protocols

     as long as limits are observed. I'll argue that the

     last paragraph is misleading . . .



     I've used Battery Tenders for years that only put

     out 3/4 of an amp or so. While under the supervision

     of one of these chargers I get these behaviors



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



    with a 1.5 Schumacher I get this



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



    When cap-checked after being on one of these chargers,

    I've had no indication whatsoever that the batteries

    were incompletely charged.   



    I cannot see that the performance of these chargers is

    inconsistent with what I read in the Odyssey technical

    literature (or anyone else's for that matter. As to these

    devices being "too small" . . . I put a fully charged 33 AH

    AGM battery on a 100 mA constant current source and in less

    than 2 minutes, the terminal voltage rose to over 15 volts.

  

    I put the battery on a 14.7 constant voltage and in

    a few minutes, the charge current had fallen to under

    100 mA. From this I infer that ANY size charter is

    probably capable of reaching and holding a top-off

    level of 14.2 to 14.7 volts and dropping to a maintaining

    level of 13.2 or so based on a nominal 'trigger' current

    for calling the battery charged.



    The point being that small chargers are capable of

    boosting the terminal voltage to the ranges recommended

    by Odyssey and others . . . it may just take more time.



    Bottom line is that for the way we use batteries in cars

    and airplanes (small percentage discharge cycles),

    there is little benefit for having any sort of charger

     . . . and at most, a $30 wall-wart Battery Tender or

    this $20 Schumacher from WalMart will suffice.



 [img]cid:.0[/img]

    The whole "aviation specific" and "desulfation" business

    is lacking foundation for either effectiveness or necessity.



    Further, specialized recharging protocols are indicated

    when trying to recover a badly depleted battery . . . but

    not when putting your airplane away at the end of the day.



 

   Bob . . .

19774d6.jpg

Description:

Filesize:

14.34 KB

Viewed:

7480 Time(s)

Hopperdhh(at)aol.com
Guest

Posted: Sun Mar 04, 2012 5:43 am Post subject: battery chargers

Hi Bob,

  

 The explosion I mentioned was in reference to a flooded battery, not  an Odyssey.  I once put a charger on my tractor and forgot about  it.  A few weeks later I found part of the battery case about 10 feet from  the tractor.  The rest of the battery was still in the tractor battery box  with the innards showing!  I assume that when the electrolyte got  below the top of the plates that some conductive debris shorted between them and  set off the oxygen/hydrogen explosion.  This experience has caused me to be  leery of battery tenders.  This could happen with even a 1/2 amp charger  because the energy that makes the spark comes from the battery, not the  charger.

  

 Thanks for the excellent information in your post on battery  chargers.

  

 Dan

 RV-7A 766DH

  

  In a message dated 3/3/2012 6:25:21 P.M. Eastern Standard Time,  nuckolls.bob(at)aeroelectric.com writes:

  	  Quote: 	
		  At 12:29    PM 3/3/2012, you wrote:

Hi David,

 

I agree with you on the type    of battery you mention.  Although, I don't know anything about a $15    tender.  If the electrolyte level gets low you can have an    explosion.  How do I know that?!!



   Let us consider the    Odyssey Technical Manual which

   may be downloaded    from:



http://www.odysseyfactory.com/documents/US-ODY-TM-001_0411_000.pdf

 

      First, I searched for the word "explosion" and didn't find

   it.    



   Next I searched for the word "damage" and I find    it

   5 times. The word is used 4 times in the context    of

   mechanical damage to the battery or damage to    surroundings

   due to leakage.  

	


 [quote][b]

ainut(at)knology.net
Guest

Posted: Sun Mar 04, 2012 10:08 am Post subject: battery chargers

During charging, offgases are produced.  If those gasses collect 

somewhere, a spark can indeed set them off.  Yes, thay can collect 

inside the battery itself.  Several RV batteries have been blown up that 

way so I assume that it happens all over the place.  Happened to me once 

and my battery compartment is well ventilated.



David M.

Hopperdhh(at)aol.com wrote:

[quote] Hi Bob,

 The explosion I mentioned was in reference to a flooded battery, not 

 an Odyssey.  I once put a charger on my tractor and forgot about it.  

 A few weeks later I found part of the battery case about 10 feet from 

 the tractor.  The rest of the battery was still in the tractor battery 

 box with the innards showing!  I assume that when the electrolyte got 

 below the top of the plates that some conductive debris shorted 

 between them and set off the oxygen/hydrogen explosion.  This 

 experience has caused me to be leery of battery tenders.  This could 

 happen with even a 1/2 amp charger because the energy that makes the 

 spark comes from the battery, not the charger.

 Thanks for the excellent information in your post on battery chargers.

 Dan

 RV-7A 766DH

 In a message dated 3/3/2012 6:25:21 P.M. Eastern Standard Time, 

 nuckolls.bob(at)aeroelectric.com writes:



     At 12:29 PM 3/3/2012, you wrote:

     Hi David,



     I agree with you on the type of battery you mention.  Although, I

     don't know anything about a $15 tender.  If the electrolyte level

     gets low you can have an explosion.  How do I know that?!!



     ------

skywagon

Joined: 11 Feb 2006
Posts: 184

Posted: Sun Mar 04, 2012 10:15 am Post subject: battery chargers

Hi Dan,

 I am wondering if the issue is confusing the design  ideas of a "Tender or Maintainer" with a garden variety battery charger of the  small 0.5 amp (or less) varieties.  

  

 Tenders or Maintainers have a pre-set cut off voltage, then  set themselves to a set "float" voltage that is considerably lower than any  battery damage causing charge voltage.  Even the tiny Harbor Freight  unit, usually on sale for less than $10, charges to a preset-'able'(*) limit and  then backs off to a float voltage.  Once in the float voltage mode they can  be left on indefinitely on any good 12 v. battery.

  

 The old fashion battery chargers, even the low amp units, must  be taken off line in a definite time period or they keep charging past their  labeled charge to usually the peak voltage of the rectified AC.  It's been  a while since I thought about this number, but, I think it can go to about 18  volts.  So, case in point, a small 0.5 amp charger could keep jamming  current into an unattended battery until it got to 18 volts.  Even, at a  small 0.5 amps that battery is going to heat up, gas out and otherwise possible  due weird stuff.  I can't see it exploding without some other form of  ignition but, it could certainly gas out and become useless.....

 Dave

 (*)  The cheap HF maintainers have inside the small  plastic control box, a circuit board mounted potentiometer.  The back can  be popped off the box and the float voltage can be adjusted for custom  settings.  I like about 13.1 v. for the float charging on 12v.  batteries.  CW lowers the voltage and CCW raises it...

  

   

 [quote]   ---

earl_schroeder(at)juno.co
Guest

Posted: Sun Mar 04, 2012 12:19 pm Post subject: battery chargers

Hi Dave,

You wrote:

"(*)  The cheap HF maintainers have inside the small plastic control box, a circuit board mounted potentiometer.  The back can be popped off the box and the float voltage can be adjusted for custom settings.  I like about 13.1 v. for the float charging on 12v. batteries.  CW lowers the voltage and CCW raises it..."

 

Unfortunately, the most recent purchases I've made do NOT include the adjustable resistor you mentioned.  They have replaced the 'pot' with a fixed resistor....

 

One can find the potentiometers at the usual places (on line) and I've replaced several fixed resistors already.

 

I've now switched from the HF varieties to the Walmart ones discussed here.  I have one per building and after the most recent used battery is recharged, I just parallel it with the other 12v batteries in that area. Works good for me!

 

Earl

 

 

   [quote][b]

skywagon

Joined: 11 Feb 2006
Posts: 184

Posted: Sun Mar 04, 2012 4:04 pm Post subject: battery chargers

Earl,

 Interesting that Harbor Freight's little unit  has eliminated the pot.

  

 I bought 6 of them last year at Oshkosh (super price) and  they all have pots.  Guess I need to be careful with them.

 Thanks,

 Dave

  

   

 [quote]   ---

Hopperdhh(at)aol.com
Guest

Posted: Sun Mar 04, 2012 5:08 pm Post subject: battery chargers

I didn't mean to confuse the issue.

  

 My tractor battery that exploded was being charged by a simple  10 A charger with just a transformer and diodes in it.  It probably would  not have happened with a charger/tender/maintainer  with some circuitry in  it to limit the float voltage to a reasonable value.  My charger was  probably putting out a little current even after the battery charged up to  16 volts or more.  Not a good idea to leave it on charge  for several weeks!!  It was winter time and I simply forgot all  about it.  Glad it wasn't my airplane!

  

 My point was that it is possible to cause big problems if  the circuit were to fail and allow the voltage to go high enough long enough to  lose the electrolyte.  Its a good idea to keep a check on the  electrolyte level (assuming a flooded battery) for that reason.  I don't  like the idea of leaving the airplane in the hangar 8 miles away with no easy  way to check on it every day or two.  Electronics is wonderful -- most  of the time.  I have repaired a few pieces of made-in-China electronic junk  that I wouldn't trust on my airplane.  I'm thinking of toys and Christmas  lights/ornaments, etc.  If the workmanship on the battery tender is like  that, forget it!

  

 Dan

  

  

  In a message dated 3/4/2012 1:16:27 P.M. Eastern Standard Time,  skywagon(at)charter.net writes:

 [quote]   Hi Dan,

   I am wondering if the issue is confusing the    design ideas of a "Tender or Maintainer" with a garden variety battery charger    of the small 0.5 amp (or less) varieties.  

    

   Tenders or Maintainers have a pre-set cut off voltage, then    set themselves to a set "float" voltage that is considerably lower than    any battery damage causing charge voltage.  Even the tiny Harbor    Freight unit, usually on sale for less than $10, charges to a preset-'able'(*)    limit and then backs off to a float voltage.  Once in the float voltage    mode they can be left on indefinitely on any good 12 v. battery.

    

   The old fashion battery chargers, even the low amp units,    must be taken off line in a definite time period or they keep charging past    their labeled charge to usually the peak voltage of the rectified AC.     It's been a while since I thought about this number, but, I think it can go to    about 18 volts.  So, case in point, a small 0.5 amp charger could keep    jamming current into an unattended battery until it got to 18 volts.     Even, at a small 0.5 amps that battery is going to heat up, gas out and    otherwise possible due weird stuff.  I can't see it exploding without    some other form of ignition but, it could certainly gas out and become    useless.....

   Dave

   (*)  The cheap HF maintainers have inside the small    plastic control box, a circuit board mounted potentiometer.  The back can    be popped off the box and the float voltage can be adjusted for custom    settings.  I like about 13.1 v. for the float charging on 12v.    batteries.  CW lowers the voltage and CCW raises it...

    

         

   [quote]     ---

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Mar 05, 2012 5:02 pm Post subject: battery chargers

At 07:41 AM 3/4/2012, you wrote:

  	  Quote: 	
		    

 Hi Bob,

  

 The explosion I mentioned was in reference to a flooded battery, not an Odyssey.  I once put a charger on my tractor and forgot about it.  A few weeks later I found part of the battery case about 10 feet from the tractor.  The rest of the battery was still in the tractor battery box with the innards showing!  I assume that when the electrolyte got below the top of the plates that some conductive debris shorted between them and set off the oxygen/hydrogen explosion.  This experience has caused me to be leery of battery tenders.  This could happen with even a 1/2 amp charger because the energy that makes the spark comes from the battery, not the charger.

  

 Thanks for the excellent information in your post on battery chargers. 	


   Oh yeah . . . I've seen flooded batteries do a

   steam explosion . . . or more like a volcano

   eruption too. A good friend of mine worked in

   the Naval Battery Labs at Crane, IN. Those

   labs are a kind of battery-hell. Many folks

   (especially submariners) wont qualify a battery

   until Crane sez, "they can't blow it up." 



   She sent me some videos of some rather spectacular

   'batterycides'.



   I am aware of only one in-service RG battery explosion.

   It was a new model Concorde being qualified onto

   a GA jet. This particular battery had been subjected to some

   severe conditions of overcharging followed by

   a couple of spool-ups (no ignition or fuel) on

   the airplane. The evolved gasses combined with

   some simulated balked starts fused a cross-over

   joint between cells . . .



 [img]cid:.0[/img]



 



   Concorde's crossovers are soldered on by hand . . .



 [img]cid:.1[/img]



     . . . and set high enough on the cell wall to become immersed  in

    epoxy encapsulant which is used to fill the inter-cell sealing

    channels in the lid . . .



 [img]cid:.2[/img]



 

    Interestingly enough, this battery design had already been

    qualified to the RTCA/TSO requirements . . . which seem not

    to stress a battery as hard as in the incident aircraft.



    Even though analysis of the event said it was not necessary,

    Concorde did beef up the inter-cell connectors in that model

    of battery.



    We have been apprised of an incidence of a high-energy,

    internal event on a Hawker 10 AH 24V battery . . .

 [img]cid:.3[/img]



    Temperatures were so high as to severely char the internals



 [img]cid:.4[/img]



 

    . . . I think this event stayed inside the battery case except

    for one small hole.



    I wasn't informed of the history of this even but given the

    battery's small size (10 a.h.) and the size of the typical

    24v alternator (60A) I'm betting that the short term high

    recharge rates for this battery were exceeded causing

    a failure of the one cell.



    The RG or SVLA battery has amassed a long history of

    robust service and few exceptions for more than benign

    failures  . . . and they get better all the time.



 

   Bob . . .

c3d2c58.jpg

Description:

Filesize:

266.48 KB

Viewed:

7453 Time(s)

c3d2ce5.jpg

Description:

Filesize:

249.46 KB

Viewed:

7453 Time(s)

c3d2d91.jpg

Description:

Filesize:

288.11 KB

Viewed:

7453 Time(s)

c3d2e2d.jpg

Description:

Filesize:

210.84 KB

Viewed:

7453 Time(s)

c3d2ed9.jpg

Description:

Filesize:

97.61 KB

Viewed:

7453 Time(s)

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Mar 05, 2012 5:30 pm Post subject: battery chargers

At 11:40 AM 3/4/2012, you wrote:

  	  Quote: 	
		  --> AeroElectric-List message posted by: David <ainut(at)knology.net>



 During charging, offgases are produced.  If those gasses collect somewhere, a spark can indeed set them off.  Yes, thay can collect inside the battery itself.  Several RV batteries have been blown up that way so I assume that it happens all over the place.  Happened to me once and my battery compartment is well ventilated.



 David M, 	




    Was there any sort of failure analysis done? Pictures

    taken? An RG battery stressed so hard as to produce

    gasses not contained in the mats combined with some

    spark-producing condition begs for answers as to root

    cause.  I would be reluctant to assume that it 'happens

    all over the place' . . . yours is the first mention

    of explosive de-construction of a battery here on

    the List in many years.



    I was aware of a battery box explosion in a GlasAir

    wherein the battery box provided containment and

    a battery contactor provided ignition. But even that

    event was poorly documented and no mention was made

    of what was probably a sustained OV event that cooked

    the battery.



    Somebody sent me an abused Odyssey some years back,

    Dec 2005 I think. I sent it to Concorde and their guys

    tore it down for closer examination.



    In this case, the battery case was intact. The battery had

    be subject to an OV condition which heated the battery up

    while building large sulfation crystals on the normally thin

    plates. The thing puffed up like a guppy.



 [img]cid:.0[/img]



 

 [img]cid:.1[/img]



 

     RG batteries are not designed to withstand severe over-charging

     or extra-ordinary stress such as that which produced the

     one real explosion I'm aware of. After running the gauntlets at

     TSO or Naval qualification labs, they are shown to offer benign

     failure events when used in a system with legacy attention paid to

     rapid mitigation of an OV event.



     If anyone becomes aware of what appears to have been an explosive

     rupture of an RG battery, please let me know about it ASAP. I'll

     pay for pictures, a narrative of conditions leading up to the event

     and pay the shipping for the carcass. These things need to be

     examined by folks who are very good at it so as to broaden our

     understanding and improvement on the best we know how to do.



 

 

   Bob . . .

c542a45.jpg

Description:

Filesize:

117.57 KB

Viewed:

7453 Time(s)

c542ab2.jpg

Description:

Filesize:

203.19 KB

Viewed:

7453 Time(s)

ainut(at)knology.net
Guest

Posted: Thu Mar 08, 2012 8:52 am Post subject: battery chargers

The explosions I referred to were in the recreational vehicles (RV) 

world, not in aviation.  In mine, I was using a state-of-the-art mounted 

charger ( as of 1986!) and did not watch the batteries closely enough so 

definitely an over-charging situation caused this.  I have since 

replaced it with a more modern unit that has float charging capability.  

The old one could vary charging rate a little but was always pushing 

electrons into the batteries.



David M.



Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   At 11:40 AM 3/4/2012, you wrote:

> 

>

> During charging, offgases are produced.  If those gasses collect 

> somewhere, a spark can indeed set them off.  Yes, thay can collect 

> inside the battery itself.  Several RV batteries have been blown up 

> that way so I assume that it happens all over the place.  Happened to 

> me once and my battery compartment is well ventilated.

>

> David M,

    Was there any sort of failure analysis done? Pictures

    taken? An RG battery stressed so hard as to produce

    gasses not contained in the mats combined with some

    spark-producing condition begs for answers as to root

<<<snip>>>

Display posts from previous:

	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