battery overflowing issues

trs79
trs79 Registered Users Posts: 3
in Off Grid Solar & Battery Systems #1
Hi all,

I bought a marine battery to learn on and the other day I had refilled it with distilled water. The interesting this is, when the water would get to the very top of the hole, if I gently rocked the battery, the level would go down. I kept doing this and adding more.

Unfortunately, when I put it on a 15 amp charge, the electrolyte rose quickly and overflowed, filling the battery container with two inches of solution. I poured the spilled acid into a bottle so I could eventually introduce it back.

My questions are:

- why was I able to fill the battery with so much water by shaking it?
- is this a bad thing to do?
- how to prevent overflowing?

Thanks for answering a battery noobs questions!
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Comments

  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #2
    Re: battery overflowing issues

    Was it a New battery ??

    1) never add water to a partially charged battery. When the battery is charged the sulfur is recombined to the electrolyte, the level will rise and out the vent.

    2) When you say " Filled " to what level ?? Just charging a overfilled battery can do it. Generally you just want the plates covered and a little extra, but never past the split ring.

    3) If it was a older sulfated battery it probably had pockets of Hydrogen / Oxygen trapped in the plates. Once they are released you can add more water and when they reform they will displace the electrolyte.
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  • trs79
    trs79 Registered Users Posts: 3
    #3
    Re: battery overflowing issues
    Blackcherry04 wrote: »
    Was it a New battery ??

    1) never add water to a partially charged battery. When the battery is charged the sulfur is recombined to the electrolyte, the level will rise and out the vent.

    2) When you say " Filled " to what level ??

    3) If it was a older sulfated battery it probably had pockets of Hydrogen / Oxygen trapped in the plates. Once they are released you can add more water and when they reform they will displace the electrolyte.

    thanks for the response. To answer your questions:

    1- the battery seemed to already be fully charged, i.e I measured it at 12.8 volts before filling but maybe it wasn't as charged as I thought?
    2 - I filled it such that the electrolyte level was about 1/8 inch below the top of the holes
    3- The battery is basically new, I bought it in February from Walmart, and it had a sticker on of 1/12, so it appeared to be fairly new

    Interesting about the hydrogen bubbles, although I don't think it was sulfated if it was as new as the label said.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #4
    Re: battery overflowing issues
    trs79 wrote: »
    thanks for the response. To answer your questions:

    1- the battery seemed to already be fully charged, i.e I measured it at 12.8 volts before filling but maybe it wasn't as charged as I thought?
    2 - I filled it such that the electrolyte level was about 1/8 inch below the top of the holes
    3- The battery is basically new, I bought it in February from Walmart, and it had a sticker on of 1/12, so it appeared to be fairly new

    Interesting about the hydrogen bubbles, although I don't think it was sulfated if it was as new as the label said.
    When you look down in the battery, your looking into a tube with the sides split. You do not to add water past the bottom of the tube. That gives the electrolyte room to expand and the slits in the sides allow the hydrogen / oxygen to escape without pushing it out.

    If it's that high you need to remove some of it. A syringe bulb type is best, I'v used a turkey baster. The problem is now it's mixed and the electrolyte ratio will be off some.
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  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    #5
    Re: battery overflowing issues
    trs79 wrote: »
    thanks for the response. To answer your questions:


    2 - I filled it such that the electrolyte level was about 1/8 inch below the top of the holes ***

    Interesting about the hydrogen bubbles, although I don't think it was sulfated if it was as new as the label said.

    #2 is your problem - you over filled it. The liquid should be near or right at the little ring or keyhole looking thing inside. Some battery instructions say to fill to 1/8th" of the filling cap, but fail to define where that is. Best bet is usually to charge the battery first and then check the levels - should usually be around 1/4" over the top of the plates, but that can vary.
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  • trs79
    trs79 Registered Users Posts: 3
    #6
    Re: battery overflowing issues
    Windsun wrote: »
    #2 is your problem - you over filled it. The liquid should be near or right at the little ring or keyhole looking thing inside. Some battery instructions say to fill to 1/8th" of the filling cap, but fail to define where that is. Best bet is usually to charge the battery first and then check the levels - should usually be around 1/4" over the top of the plates, but that can vary.

    I was afraid of that. Do you know why I was able to get more water in by shaking the battery?
    Blackcherry04 wrote: »
    When you look down in the battery, your looking into a tube with the sides split. You do not to add water past the bottom of the tube. That gives the electrolyte room to expand and the slits in the sides allow the hydrogen / oxygen to escape without pushing it out.

    If it's that high you need to remove some of it. A syringe bulb type is best, I'v used a turkey baster. The problem is now it's mixed and the electrolyte ratio will be off some.

    I need to get a hygrometer to see how much I've messed up the ratio...:confused: I didn't know that about the split sides, maybe I was forcing water into those splits which didn't leave any room for the gas?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,649 admin
    #7
    Re: battery overflowing issues

    Because you will never be there every time the batteries are recharged--Just keep the electrolyte level lower and only refill if you need to keep the plates covered (prior to recharging--as you have seen). Normally, you only want the water level to just touch the bottom of the split ring (if present in your battery). Never fill it to near the top of the splits.

    Keep an eye on your water usage--If you are refilling every 2-3 months--you are probably charging OK. If you are refilling every month or every few weeks, then you might be over charging.

    Note that some of the batteries out there appear to use less water (the new Trojan batteries for solar appear to use less than the old designs)--Normally I would say if you are refilling every 6-12 months, you may be under charging.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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