running cell dry damage

blackswan555blackswan555 Solar Expert Posts: 246 ✭✭
What damage does running a cell partially dry do ? eg exposing the top of the plates for a few months ?
Thanks in advance,
Have a good one
Tim

Comments

  • BB.BB. Super Moderators, Administrators Posts: 28,998 admin
    Re: running cell dry damage

    Will cause the plates to warp/crack as they dry out. I.e., very bad for life of cell/battery.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,124 ✭✭✭✭
    Re: running cell dry damage

    Couple of months???

    Can you spell scrap metal value?

    Tony
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,419 ✭✭✭✭✭
    Re: running cell dry damage

    A complete loss in confidence in anyone associated with the installation and maintenance!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • blackswan555blackswan555 Solar Expert Posts: 246 ✭✭
    Re: running cell dry damage
    A complete loss in confidence in anyone associated with the installation and maintenance!

    LOL but thankfully not,
    My re-work of install over a year ago, Hasn`t missed a beat otherwise, but customer insisted on doing his own maintenance, I spent about 5 hrs "instructing him" on SG`s/Service & took him through most of an EQ, He promised to check SG`s & levels and EQ max every 2 months,,,,,,,,
    Bats are rolls 6cs21p`s x8 , 24v , 2 x parallel strings, 1366ah @ 20hr total,

    Email below:roll:
    I have f**ked up massively with the batteries. Basically I have not checked them in a while as I have not been living in the house for nearly a year. I moved back in just before xmas and noticed that the genny was coming on more than it should. After checking the batteries I have seen that the acid level was way low. Actually below the plates. I have had to put in about 700 ml of water just to get the level over the plates. I know this is a monumental f**k up. I'm charging the batteries as we speak. Last night was the first time They were charged with the new levels. When I woke this morning the bats were way down so I have put thew genny back on and will keep charging them. what I need to know is
    a. Do you think the bats will come back.
    b. do you think they are completely f**ked.
    c. If they are f**ked can they in some way be fixed.


    Have a good one
    Tim
  • halfcrazyhalfcrazy Solar Expert Posts: 719 ✭✭✭
    Re: running cell dry damage

    Boy that's a tough pill there. I would venture a guess they are irreversibly damaged. They may continue to give some life but never the life they used to.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: running cell dry damage

    plates should never be exposed to the air and even if they work somewhat now, they are diminished in capacity and are inevitably going to need replacing sometime soon. mine went about 3 or 4 months babying them before i replaced them. maybe a sealed agm battery would've been better as they need less maintenance.
  • BilljustBillBilljustBill Solar Expert Posts: 212 ✭✭✭
    Re: running cell dry damage
    niel wrote: »
    plates should never be exposed to the air and even if they work somewhat now, they are diminished in capacity and are inevitably going to need replacing sometime soon. mine went about 3 or 4 months babying them before i replaced them. maybe a sealed agm battery would've been better as they need less maintenance.

    As a spin on the exposed plates information, I have a question.

    If the battery has never had acid, but was stored with some of the caps being left off, would the battery be rated as new or considered to have a shorter lifespan when acid is put in and it becomes active?

    Bill
    Bill
  • BB.BB. Super Moderators, Administrators Posts: 28,998 admin
    Re: running cell dry damage

    From our Host's Battery FAQ:
    Even the so-called "dry charged" (where you add acid when you need them) have a shelf life of 18 months at most. They are not totally dry - they are actually filled with acid, the plates formed and charged, then the acid is dumped out.

    These are some typical (minimum - maximum) typical expectations for batteries if used in deep cycle service. There are so many variables, such as depth of discharge, maintenance, temperature, how often and how deep cycled, etc. that it is almost impossible to give a fixed number.
    • Starting: 3-12 months
    • Marine: 1-6 years
    • Golf cart: 2-7 years
    • AGM deep cycle: 4-7 years
    • Gelled deep cycle: 2-5 years
    • Deep cycle (L-16 type etc): 4-8 years
    • Rolls-Surrette premium deep cycle: 7-15 years
    • Industrial deep cycle (Crown and Rolls 4KS series): 10-20+ years
    • Telephone (float): 2-20 years. These are usually special purpose "float service", but often appear on the surplus market as "deep cycle". They can vary considerably, depending on age, usage, care, and type.
    • NiFe (alkaline): 5-35 years
    • NiCad: 1-20 years

    I believe that dry charged batteries are supposed to be "sealed" while stored... It is possible, I would guess, that if the cells are allowed to "full dry out" that the plates could crumble/fail (or fail earlier).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RCinFLARCinFLA Solar Expert Posts: 1,280 ✭✭✭
    Re: running cell dry damage
    As a spin on the exposed plates information, I have a question.

    If the battery has never had acid, but was stored with some of the caps being left off, would the battery be rated as new or considered to have a shorter lifespan when acid is put in and it becomes active?

    Bill

    A dry charge battery will have the negative plate oxidize so it become more like a positive plate. It does not do real damage but the initial charge after electrolyte is added will take longer.

    I don't think anyone makes a true dry charge battery any more. The manufacturing process uses a lead-acid slurry to paste the plate and pre-forms the postive plates to reduce the initial forming charge period. The residual acid will sulfate the plate if exposed to air for a long period. Some fill the battery with distilled water that need to be emptied out.
  • peakbaggerpeakbagger Solar Expert Posts: 341 ✭✭✭
    Re: running cell dry damage

    Well unless they are nickel iron batteries (very doubtful), they are probably in pretty bad shape. I normally warn folks who have off grid camp systems in my area that their first set of batteries are only going to last to 1/3 to 1/2 the expected life due to poor maintenance. Usually they dont believe me until a few years later when they have to write a check for a new set of batteries after they have tried to blame the person who sold them the batteries that they were defective. Usually after this expensive lesson, they figure it out that maintenance isnt optional.

    I have also observed that any system that is in place when a house is bought or sold is most likely doomed to a minimum of a battery change out, and frequently becomes parts for sale.
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