Should a 12V 75AH AGM battery make noises during charging?

Discussion in 'General Electronics Chat' started by foolios, Jan 31, 2015.

  1. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    I bought a quick charger for a 12V 75AH AGM battery, the solar battery type(Chrome Battery). During charging, I noticed a faint gurgling sound coming from the battery. I've never recharged any of my AGM batteries with as much inrushing current as this recharger can do. It's pushing in approximately 3 amps of current.
    Is this normal?
    I've also tried the charger on the 35AH AGM battery that I have and it does the same thing until the recharger goes into maintain mode.
     
  2. #12

    Expert

    Nov 30, 2010
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    IMHO, sealed batteries shouldn't gurgle. :eek:

    Certain sources say a C/10 charge rate is good, but I believe my personal wisdom.
     
  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Maybe with a "tickle" charge. ;)

    What sort of noise are you hearing? Are you using pulse charging? I don't think a little gassing will cause noise, but pulse charging might.

    John
     
  4. wmodavis

    Well-Known Member

    Oct 23, 2010
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    Maybe he hears a wee small voice in there saying "I get a charge out of this".
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    From Battery Univ site:
    "As with all gelled and sealed units, AGM batteries are sensitive to overcharging.
    These batteries can be charged to 2.40V/cell (and higher) without problem; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages).
    Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell), and a direct replacement with a sealed unit could spell trouble by exposing the battery to undue overcharge on a long drive. "
    Max.
     
    Roderick Young likes this.
  6. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    I got this charger: http://www.amazon.com/Schumacher-SS...er-Battery/dp/B000H961YI/ref=cm_cd_al_qh_dp_t
    It says it is for AGM.
    I have tried it on a 35AH AGM battery and a 75AH AGM battery. These are Chrome Batteries for solar battery backup systems. Both of them when charging at approximately 3 amps draw will make a faint bubbling sound. I do not smell any gases being released after the full charge is complete.
    I was wondering if Lead Acid Batteries make any sounds during charging or discharging. I have never had that much juice going in or out of the batteries before so I am unsure.
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    As stated above, batteries do not make noise when supplying or being charged with pure DC. Second, the products from simple gasing do not have an odor.

    You have not described the sound yet. Is it gurgling, thumping, or a buzzing?

    Finally, the Amazon description includes this, "Multi-stage charging allows a battery charger to automatically cycle between a variety of charging phases including desulfation..."

    Desulfation may involve pulse charging. Some people describe the process as physically disruption/shaking the hard sulfates apart. That might cause a thump or buz depending on the frequency.

    John
     
  8. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    I'm going to try to describe it more like a bubbling sound. That's about as close to how it sounds, but not exactly.
    If the A/C quick charger is in desulfation mode, what amount of amps will it likely use to perform that function? And do chargers do desulfation during charging mode or during maintaining mode? During charging mode, there is 3 amp draw on the 12V DC side; there is .3 draw on the 120V AC side. Hopefully this extra information helps.
    This is seemingly strange, not normal behavior, as I am not finding anything about batteries making faint sounds. But noone who has used the product or its cousins are complaining about anything similar.
    I am guessing that somehow I've got something weird going on. I've got the charger plugged into the 120V wall outlet. I've got it set on AGM setting and 3A charge setting(I've tried the 15A charge setting too). It shows voltage on the display and it shows %SOC as well.
    Everything seems to function properly but that the battery is making sound.
    Thanks for all the insight thus far.
    Oh, and the charger has a reverse hookup warning and that's not going off. That does work, it'll tell ya right away. hehe
     
  9. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    I seem to have resolved the problem with the bubbling batteries.
    Before charging I had the batteries hooked up in parallel to other batteries for solar charging.
    I had unhooked the positive side cable thinking that there wouldn't be any issue with charging the one battery. I figured it was the same as taking it all the way out of the branch.
    It appears I was mistaken. Even just having the negative side connected in parallel to another battery even though the positive parallel connection was removed was causing the charger to elevate to a higher charge voltage.
    Without that one wire connected from the other battery, the charge voltage is around 14.4V.
    When that one wire was connected on the negative posts of each battery, the charge voltage reached 15.2V.

    If someone could explain to me why this was happening, I would really appreciate it.

    THanks in advance!
     
  10. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Doesn't sound logical. Can you draw what you had or thought you had?

    John
     
  11. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    A ground loop between the charger and the battery bank? All of the commercial chargers I have (and the ones I have built myself) are totally isolated from the green wire in the three wire AC line cord, but maybe yours isn't? Ohmmeter it to check.
     
  12. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    I may have had more than one battery connected with the negative in parallel like this. Not gonna retry to verify though...

    [​IMG]
     
  13. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    The battery on top should not noticeably affect the voltage you need to charge the battery on the bottom. (See this current thread for a somewhat related question: http://forum.allaboutcircuits.com/t...y-will-battery-produce-more-electrons.106407/ )

    In other words, you have a very strange observation and apparently don't want to expend the effort to reproduce it.

    It also appears you have stopped hearing the noise from your batteries. So, problem is solved, and I guess we wasted our time taking your question seriously based on science.

    John
     
  14. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    The battery on top should not noticeably affect the voltage you need to charge the battery on the bottom.
    I had originally guessed that it would not. Thinking I could save myself some time, I half-way disconnected the batteries.
    But since noises were created in having left it like that, I can only assume it did indeed affect the charging voltage.

    In other words, you have a very strange observation and apparently don't want to expend the effort to reproduce it.
    I did not want to duplicate out of fear that I was damaging my batteries based on the responses that they should not be making sounds during charge.

    It also appears you have stopped hearing the noise from your batteries. So, problem is solved, and I guess we wasted our time taking your question seriously based on science.
    I had mentioned in a previous post that by removing that connection, the charge voltage dropped to 14.4V

    What I am guessing had happened was that while that extra connection existed, the charge voltage would reach 15.2V thus causing the AGM batteries to boil.
    Without that connection, the charge voltage would hit the ceiling at 14.4V and the batteries would not reach the boiling point.

    As for why that occurs, I am still wondering about it. But I am happy that it is not doing it so long as I don't leave them connected like that.

    Thanks
     
  15. MrChips

    Moderator

    Oct 2, 2009
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    What you are describing is totally unscientific. A battery with only one terminal connected has absolutely no effect on the rest of the circuit.
     
  16. Roderick Young

    Member

    Feb 22, 2015
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    I had a pair of 12V, 12AH Sealed Lead Acid batteries that I was using for bench power. They were quiet during charging at 2A. But then one day, I heard a faint fizzing / hissing sound. Didn't think much of it, but then noticed that the charger LED was never turning green, which would indicate that the 24V bank was charged. I disconnected the batteries and found that one was only putting out like 10 volts, even after all that charging time. Looks like one of the cells inside shorted somehow, and I was therefore overcharging the rest of the cells. I'm not saying this is what's happening to you, but it's worth checking the battery voltage to make sure.
     
  17. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    That is very interesting. I just recently put my bank back together. But as soon as I unwire them again, I will check their voltage individually and report back.
    I should be rather motivated now that I fear that one of them may be faulty.
    Thanks for the info.
     
  18. Lestraveled

    Well-Known Member

    May 19, 2014
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    I bought the 10 amp version of this charger. The first time I used it, it brought the battery voltage up to 16.5 volts. I thought it was broken. I called Schumacher and they said this is the correct voltage it was programmed for. I tried other battery settings to get the voltage down to a more reasonable value, with not much luck. I only use this charger for flooded batteries that need an equalization charge. Never never use this charger on an AGM battery. The voltage is just too high.
     
  19. foolios

    Thread Starter Active Member

    Feb 4, 2009
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    It's been a while since I messed with those AGM batteries.
    But just to update, I never really did figure them out.
    I replaced them with flooded and am having a better experience. Maybe the charger destroyed them(AGM's) or I let them discharge too deeply, too often.
    Either way, not being able to open them up and check the specific gravity like I can with my flooded was just irritating.
     
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