Connect with us

Batteries and Hydrogen

Discussion in 'Photovoltaics' started by George Ghio, Apr 17, 2005.

Scroll to continue with content
  1. George  Ghio

    George Ghio Guest

    ³It's amazing that you can get all that energy from a chemical reaction
    occurring inside that little black box. But, along with that chemical
    reaction you get something else, HYDROGEN VAPORS. Do you remember the
    Hindenburg? No, I don't mean you're that old. You probably heard about
    it from your parents or grandparents, right? Well let me refresh your
    memory. Apparently a static electrical spark was all that was needed to
    ignite the hydrogen vapors that the Hindenburg used to stay afloat.

    These same explosive vapors are present anytime your battery charges OR
    discharges. And all it takes is a little spark to ignite those fumes and
    cause an explosion. Your battery contains sulfuric acid and water.
    During the chemical action created during charging or discharging,
    hydrogen vapors are released and then are trapped under the hood.²





    Just some of the resulting information on batteries after a search on
    google for <exploding batteries discharging>.

    Sort of puts paid to the experts (ex - a has been, spurt - a drip under
    pressure) here who would have you believe that batteries do not produce
    hydrogen during discharge.

    Seems that George was right after all. Still thats no surprise.
     
  2. m II

    m II Guest


    The fine silvery aluminium powder used in the fabric 'dope' probably contributed
    to the fire more than the hydrogen. There is also a question of whether the
    Hindenburg was sabotaged by US forces for propaganda purposes.





    mike
     
  3. No need of hydrogen if you have an onboard (11-B)2O3-cooled
    nuclear reactor. It might make for a somewhat big car,
    requiring extra-thick roadway foundations.



    --- Graham Cowan, former hydrogen fan
    http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html --
    how individual mobility gains nuclear cachet
     
  4. George  Ghio

    George Ghio Guest


    The fine silvery aluminium powder used in the fabric 'dope' probably
    contributed
    to the fire more than the hydrogen. There is also a question of whether the
    Hindenburg was sabotaged by US forces for propaganda purposes.





    mike[/QUOTE]

    So. Batteries still generate Hydrogen during charging and DISCHARGING.
    Dispite the claims by several self styled experts in these groups.
     
  5. Me

    Me Guest

    So, the relative probubility of having a battery explode, while either
    charging, or discharging, is insignificant, when compared to the number
    of batteries in use around the world, on a daily basis. A Jet airplane
    engine can fall out of the sky a hit you on the head, but your chances
    of that happening, are insignificant as well. Just our luck..........


    Me
     
  6. I hope you can show us the cell reactions for these reactions !


    J/.
     
  7. daestrom

    daestrom Guest

    Care to discuss amounts? Does a battery that is being charged at 20 amps
    generate the same amount of hydrogen as one being discharged at 20 amps??
    What about the voltage level, does a battery that is being charged at 20
    amps at 2.2 volts per cell at the beginning of re-charging generate the same
    amount of hydrogen as a battery being charged the same 20 amps, but later in
    the charge at 2.5 volts per cell? You should find that the amount generated
    during *discharge* is much less than that generated when/if overcharging.

    In commercial stationary battery applications, it is quite common to have
    *different* ventilation requirements for charging and discharging. Yes,
    discharging or floating still requires ventilation and safety precautions,
    but *charging* evolves more hydrogen.

    daestrom
     
  8. m II

    m II Guest

  9. George  Ghio

    George Ghio Guest

    Well, do the search on google,

    "exploding batteries discharging"

    Lots of pages. Have fun.
     
  10. George  Ghio

    George Ghio Guest

    Oh yes. Charge at C10 and discharge at C120. Different ammounts of gas.

    Point being made is that Nick, et al have stated that batteries do not
    produce gas during discharge. They are wrong.
     
  11. Windsun

    Windsun Guest

    I did that, and almost nothing comes up to support your claims. But, then
    most of your claims about anything that I have seen in newsgroups in the
    past year or so are not supported by any facts. This just continues the
    trend.
     
  12. daestrom

    daestrom Guest

    Charge at the same rate as discharge. The amount of hydrogen evolved is
    very different.

    Interestingly, when first charging a deeply discharged battery, it evolves
    almost pure oxygen and very little hydrogen. Only as it nears full charge
    does it start to evolve hydrogen. And the amount is greatly depending on
    the cell voltage-temperature-current. Excess voltage will evolve a lot more
    H2 and O2 than proper charging.

    daestrom
     
  13. daestrom

    daestrom Guest

    Hydrogen evolution during discharge is almost entirely side reactions with
    plate impurities. As such, quality batteries evolve very little compared to
    charging.

    daestrom
     
  14. George  Ghio

    George Ghio Guest

    When you stop looking at the sun your sight will come back (maybe)


    Exploding Battery: Batteries generate explosive gases during operation
    and when charging. Flames, sparks, burning cigarettes or other ignition
    sources must be kept away at all times.

    http://www.rpc.com.au/reindex.html?http://www.rpc.com.au/products/efn/efn
    extracts/batteries_care.html


    The byproduct of discharging or charging batteries is an explosive gas.

    http://www.sptnetpower.com/safety.htm



    These same explosive vapors are present anytime your battery charges OR
    discharges. And all it takes is a little spark to ignite those fumes and
    cause an explosion.

    http://www.signonsandiego.com/marketplace/autocenter/carguys/000211batter
    ies.html




    We all know that hydrogen is explosive; let's keep in mind for
    a moment that it reacts specifically with the oxygen in the air when it
    explodes. One more thing to keep in mind: these batteries also produce
    hydrogen when discharged.

    http://observers.org/tac.mailing.list/2001/Dec/0013.html
     
  15. George  Ghio

    George Ghio Guest

    Depends entirely upon the rate of charge ao discharge.
     
  16. daestrom

    daestrom Guest

    Hydrogen evolution on charge is a function of temperature, voltage and
    current. Proper charging includes limiting the voltage for a given
    temperature until reaching the finishing rate. Only when the charging
    current is down below the finishing rate should voltage be allowed to rise
    above the gassing voltage. This *greatly* reduces the amount of hydrogen
    produced. Of course, improper charging can generate huge amounts of gas,
    overheat the battery and even boil the electrolyte.

    Incidently, it is interesting to note that when first starting the charge of
    a deeply discharged lead-acid battery, almost *pure OXYGEN* is given off,
    and very little hydrogen.

    Hydrogen evolution on *discharge* is very small in comparison. Discharging
    as high as the 3 hour rate doesn't produce very much hydrogen. Ventilation
    is still required, but not anywhere near the requirements during battery
    charging.

    daestrom
     
  17. George  Ghio

    George Ghio Guest

    I don't remember saying any different.

    It is also interesting to note that oxygen is an accelerant and hydrogen
    is explosive in the range of 5 to 95%.

    Think about it.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-