Battery CCA

Discussion in 'Technical' started by shineyzx, Sep 20, 2015.

  1. tassuperkart

    tassuperkart Its a lie I tell you!

    Thanks ECZ but these figures mean little in this case.
    You state that this is a box stock setup with a fully charged battery. Even at best case scenario, dead stock, the stock battery is being treated very harshly by a stock alternator.

    Newhoo

    E
     
  2. East Coast Z

    East Coast Z Well-Known Member

    How exactly is the battery being treated very harshly by a stock alternator?
     
  3. tassuperkart

    tassuperkart Its a lie I tell you!

    Being grossly overcharged.
     
  4. East Coast Z

    East Coast Z Well-Known Member

    How much grossly overcharged is it & over what amount of time?
     
  5. tassuperkart

    tassuperkart Its a lie I tell you!

    *Warning* Rant ahead.

    I cant remember the exact figures now for lead/acid cell charge rates. Its been too long now but the individual cells have a figure that they will accept and overcharging is dissipated as heat and increased hydrogen gas production.
    The hotter the cells become, the lower the internal resistance of the cells and so the higher the charge rate the battery will "appear" to accept so the increase production of heat and hydrogen, so the internal resistance lowers, so the charge rate accepted increases in a useless cycle and in really extreme cases results in a thermal runaway, the plate temps rise to the point that the lead fails, creates a spark and the battery goes China Syndrome or even BOOM!
    Some might believe that the higher the charge rate, the faster the battery will charge but thats not how it goes. the battery VOLTAGE will rise quite quickly but the battery CAPACITY does not.
    In a way like forcing a turbocharger past its efficiency range. You just dont get anything useful apart from explosive gas and heat overcharging.
    Introduce sealed maintenance free and gel batteries that cannot vent the hydrogen gas so easily. It would usually be chemically reconstituted at its own rate within the battery but in overcharge condition just pressurises the already heated and softened battery case, eventually distorting it and mechanical damage of the battery plates can result.

    Look, all of this goings on is in very extreme cases and thermal runaways occur more frequently in Ni-Cad batteries that are far more susceptible to the temp/internal resistance relationship but the bottom line is that an itty bitty battery suitable for a motorbike and a big f**k-off altermahooter, even tho it does the job, will die in the arse in very short time in comparison to what is specified stock.
    The failures are usually quite immediate rather than a gradual loss of battery reserve capacity under much more usual circumstances.

    Its all food for though rather than a direct warning.

    I put a lot of these rantings up as i see so many of you who seem to feel the need to set your road car up as full race car.
    Wasting preposterous amounts of money on lightweight this and trick compound that with all this race spec clobber... and for what?
    The very vast majority of you guys NEVER actually drive these vehicles to the point where such clobber is even being exploited and in fact, something like brake pads, results in less predictable braking behaviour, heavier everyday pedal pressures and skyrocketing disk and pad wear because the components never even get hot enough to actually do the job that the stock parts handle perfectly. But must have because race car does...... gawwd.

    A glaring example of this is the nefarious practise of "upgrading" cooling systems.
    has anybody ever noticed that apart from plain just failed stock parts, the ONLY people who have recurring cooling system issues are those with mega-dollar aftermarket radiators, fan and shrouds removed, half a dozen electric fans as a must have? Turning off AC systems and running heaters in traffic and whatnot?
    Yet, those of us with bone stock cooling systems drive around on a stinking hot and rainy day, AC set to comfort, wipers wiping, defoggers defogging and lights blazing and the rockbox pumping not giving a shite and laughing at the rest of you must have race modded ass-clowns boiling over because you were sucked into some must-have big assed blingey radiator and some bullshite funky electric fan setup and the whole show wheezing and farting when the temp reaches about 30 outside in standstill traffic?
    Oh yes, out batterys didnt go flat either as the entire system is designed to run near on indefinitely at full load at idle rpm.....manufacturers pay quite a bit of attention to that when R&D'ing these jiggers!!
    It seems a fair percentage of us know something better....?

    The list goes on interminably with useless breather catch cans system, giant twin fuel pump installs on a slighty boosted 350Hp engine, massive oil cooling setups when oil temps were never an issue in the very first place but all this garbage MUST have because race car!!!!!
    The vast majority of this aftermarket "performance" clobber has about as much positive effect as placing a column of white go-fast brand stickers down the front of the door line!!!!

    An old saying I like, "To be old and wise, one must first be young and stupid".
    Been there, done that!!!!

    LOL /rant!

    E
     
  6. stumagoo

    stumagoo Active Member

    While I can see that ECZ and others have reason beihnd them and coupled with the fact that figures like ECZ has put up are exactly how the alternator should be working I am inclined to go with Tassuperkart here.

    If we remove the car itself and look at traditional charging of a battery the slow/trickle charge has always (so I have always been told) been the best method of charging a battery, everything form nicad to wetcell, big modern chargers especially those with a boost and/or jump start function often have disclaimers in them to not leave them on high amp output for charging. I have also been told by several more experienced mechanics etc that you never charge a dead flat battery with the car alternator, always use a trickle charger.

    All these points tell me that modern alternators with all their amps are not actually that great on batteries - add to this the amount of times cars in our panel shop come in with dead batteries that cant hold a charge for more than 12 hours - I have to agree with Tas
     
  7. andy

    andy Member

    CTEK MXS25 Charging cycle 40-500 Ah Batteries

    [​IMG]
     
  8. tassuperkart

    tassuperkart Its a lie I tell you!

    Baaahahahaha whats that? For a frikken electric forklift LMAO!!!!!!!
    E
     
  9. andy

    andy Member

    According to CTEK the MXS25 is designed to charging a 50 to 500 AH battery.

    The CTEK MXS 3.8 is designed for a 1.2 - 80 AH battery.

    [​IMG]
     
  10. Peter Black

    Peter Black Active Member

    What about being old and wise enough to make your stupid ideas actually come to life?

    How 'sensible' are your ute and Plusar?

    :D
     
  11. Fists

    Fists Well-Known Member

    Battery that's been in my Z since I got it has always been much happier than any I've put in my datsun with it's gentle little 30A alternator, just sayin'.
     
  12. tassuperkart

    tassuperkart Its a lie I tell you!

    Ok.. so define a "happy" battery?
    E
     
  13. Fists

    Fists Well-Known Member

    Holds charge, delivers cranking amps.
     
  14. tassuperkart

    tassuperkart Its a lie I tell you!

    Well, if the Datto didnt do above "happily", then I submit that something was wrong with it. Or it was rarely driven.
    One or other.

    E
     
  15. East Coast Z

    East Coast Z Well-Known Member

    Basic description of how an alternator works, the current & demand section may be of interest.

    http://www.bcae1.com/charging.htm

    If a battery is overcharging, the alternator is probably defective.
     
  16. QLDZDR

    QLDZDR ID=David

    Well, I am replacing my battery. In 5 years I am on my 2nd replacement.
    The original Supercharge NS70 was replaced with a similar dimensioned Century NS70 610cca battery. It has an overcharging limiter so I thought it would be a long lasting battery.
    Lasted 24 months, got a replacement under warranty which has lasted 13 months.

    Century now recommends an 810cca MF 4wd battery for 300zx
     
  17. stumagoo

    stumagoo Active Member

    I wonder if this is because that modern batteries are either rated more optimistically or designed to be high output at the expense of durability. In the past (90's and earlier) a 700cca battery would have been a physical monster, probably 11 or 13 plate and the sort of heavy duty thing reserved for big diesels and small comercial trucks. now it seems they are the size of what I would have expected a 450cca or similar battery in the past to be. and then these batteries would have lasted a lot longer than they do now days. Hell I have had motorcycle batteries rated higher than my old datto's battery that was 3-4 times the size of them. That dattos battery lasted for me 5 years no issues (the whole time I had that car) my bike batteries lasted an average of 2.
     
  18. rob260

    rob260 Administrator Staff Member

    Your battery is not failing due to "lack" of CCA. Suggest a more thorough test of starting & charging systems.
     
  19. Gunwarm

    Gunwarm Kamikazee Special Corps

    Thanks for that :br: I will get 3 one for each car :rolleyes2: never have to much of a good thing :agree:
     
  20. QLDZDR

    QLDZDR ID=David

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