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joe0508's avatar
joe0508
Explorer
Sep 23, 2018

battery

I have a 12v starting battery that i am trying to recondition using a charger.The battery is bubbling water around the fill caps.I have never seen this before and wondering if someone can shine some light on the subject?
  • joe0508 wrote:
    I left it bubbling for like an hour or more do you think it is safe to hook back up?


    Clean it, check that the electrolyte level in all the cells is okay (and top off if needed), and I suspect you'll be good to go. The worst case scenario is that you discover the battery isn't working, but you'll never know until you try it out or otherwise test it. If you have a hydrometer, check the specific gravity in each of the cells to make sure they're all about the same (which indicates fairly well that none are shorted). Assuming they were bubbling more or less equally, there probably isn't a completely bad cell.

    An occasional modest overcharging is not a terrible thing for a battery; among other things, it makes sure all the cells are fully charged at the same time. Obviously you don't want to do this super frequently, nor overdo it.
  • I left it bubbling for like an hour or more do you think it is safe to hook back up?
  • I checked to see the charge on the battery and it was fully charged.The charger never gave me any indication it was finished.I guess i was overcharging it?
  • What is the voltage on the battery terminals? Probably a shorted cell. Trade the battery in.
  • ...you are over charging your battery with too much amperage. Bad for the battery and bad for you...

    This from google:

    When charging amperage exceeds the level of the natural absorption rate, the battery may overheat, causing the electrolyte solution to bubble creating flammable hydrogen gas. Hydrogen gas, when combined with oxygen from the air, is highly explosive and can easily be ignited by a spark. You shouldn't boil them.
  • You should fill to the bottom of the slit caps when the battery is fully recharged. That leaves room for the electrolyte to expand up the cap slots when you next do a recharge. If you over-fill when cold, the fluid will spill out of the cap tops when you recharge at a higher sort of voltage.

    Next is the higher sort of voltage. If you really crank up the voltage, to over 16.5 say, you will get spilling out the tops in a big way.

    Reconditioning is a necessary thing at times, but easy does it.

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