CCA vs Ah

Discussion in 'Outboards' started by Vronsky, Oct 29, 2025.

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  1. gonzo
    Joined: Aug 2002
    Posts: 18,038
    Likes: 2,261, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Usually MCA is specified for boats and not CCA. The difference is the temperature at which they are rated. MCA is higher than CCA. However CCA is rated at -18C (0F) which means the water is frozen.
     
    gonzo, Oct 31, 2025
    #16

  3. pistnbroke
    Joined: Jan 2009
    Posts: 1,433
    Likes: 40, Points: 48, Legacy Rep: 404
    Location: Sadly in the UK

    pistnbroke I try

    CCA is the current applied for 3 min that will reduce the battery to 6v at -18 C.
    The charging system on any boat or car will not be more than about 15A charging current as its driven by the difference between battery voltage and the output voltage of he alternator.....
    MCA is at 0 deg c. A fully charged battery at -18 deg C will have its electrolyte turned to a jelly
     
    pistnbroke, Oct 31, 2025
    #17
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