batteries and baking soda

t00lst00ls Solar Expert Posts: 212 ✭✭✭
Everyone knows that baking soda is a necessity when operating a battery powered inverter..right?for when you get an acid spill.
I had a couple of old batteries that were sulphated in one cell,so I figured I would try an experiment. I drained all the electrolyte out of the battery.then I took a gallon hot tap water and mixed in baking soda. I first poured the mixture in the dead cell and of course it started bubbling like I expected.I then poured the remaining mixture in the remaining cells,they did not bubble as much as the dead cell...hmm,however they did bubble.after about a half hour I emptied the battery out then rinsed it out while it was upside down,all the sediment came out and any other crud that was in there.
I then let it drain upside down for a while to let the plates get all the water out.then I took new electrolyte and put it first in the dead cell lots of bubbling ,then filled the other cells,hardly any bubbling
when I started all this the battery was at 10 volts and a load test would pull it down to zero at a flick of the switch. after charging for 2 hours 40amps 14 volts the load test revealed a 12.8 charge the load test went down to 10 volts after 10 seconds twice.So I charged it some more 30 minutes on the 200 amp setting then an hour on the 40 amp setting. After letting it set for an hour the load test then showed a battery at 13 volts and loaded for 10 seconds four times each gave me a 12 volt reading each time.
my thinking on this was since the cell had sulphation crystals on the plates ...the baking soda would neutralize the sulphation thereby removing the short in the cell
Im doing a 2 amp charge for 6 hours right now...when i check after sitting all day I will give you the load test and specific gravity readings

Comments

  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: batteries and baking soda

    sounds very interesting, but how do you plan to get all of that baking soda out of the cells? it bubbled when acid went in because of that baking soda still leftover in the cells. it is possible the baking soda freed up some of the sulphation you had experienced with the battery, but how much of that sulphation did it in fact get rid of? we don't really know. the new acid was partially neutralized by leftover baking soda in the cells and the bulk of the really hard encrusted sulphation may in fact still be there. there may even be plate damage in there making any reversal of sulphation a wasted effort even if your efforts to reverse the sulphation are successful to whatever degree. better controlled methods under laboritory conditions would better determine what happened and whether or not successful enough to be worth any pursuit in revamping batteries.
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: batteries and baking soda

    While it might be an interesting experiment, you are not doing anything that will save or improve the batteries.

    Baking soda is nothing but sodium carbonate, when mixed with acid it neutralizes it and also makes CO2, which are the bubbles.

    BTW, batteries very seldom sulphate in just one cell. If only one cell is bad, there is probably a lot more wrong than just sulphation.
  • t00lst00ls Solar Expert Posts: 212 ✭✭✭
    Re: batteries and baking soda
    niel wrote: »
    there may even be plate damage in there making any reversal of sulphation a wasted effort even if your efforts to reverse the sulphation are successful to whatever degree. better controlled methods under laboritory conditions would better determine what happened and whether or not successful enough to be worth any pursuit in revamping batteries.
    well noted niel.as i said they were old batteries,not over 3 years old that havent had a charge on them for 2 years because one cell went dead.I understand that the SG had went down because leftover baking soda....I've been testing the SG off and on all day,even equalizing it out with electrolyte from the other cells,it seems to be working as now all the cells give that familiar bubble when at high voltage charge ,where before the one cell did not do that before
    still after I take it off charge tonight ,I will wait till tomorrow evening to post the results
    If all goes well,I may come up with a more precise way to do this,I still have 2 more batteries that I can do this with,and one more that is currently in use,though that one just has a low SG in one cell
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: batteries and baking soda

    ok. you may have gained a bit of life to the batteries, but for how long and what is your new ah capacity? my guess would be not for long and a much lowered capacity. batteries damaged even by sulphation are still damaged batteries and may not be worth the efforts you've put into it. i don't believe you would be the first to have tried this either.
  • mike95490mike95490 Solar Expert Posts: 8,288 ✭✭✭✭✭
    Re: batteries and baking soda

    I think you wasted a lot of acid and baking soda for nothing, and still have batteries to dispose of.
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  • t00lst00ls Solar Expert Posts: 212 ✭✭✭
    Re: batteries and baking soda

    just checked battery this morning with a load test,its been off charge for over 24 hours the load test reads 12.5 volts dont have time this morning to read the SG will post later
  • t00lst00ls Solar Expert Posts: 212 ✭✭✭
    Re: batteries and baking soda

    well...after sitting all day again no charge the SG readings are all 1275 and the cell that was dead is at 1250
    the load test was done repeatedly every minute for 5 minutes @ 10 seconds the battery reads 12.50 while the load switch is depressed
    I've already started tryin this on another battery,this one has 2 dead cells...
    I will post more results this weekend
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