Which battery: CCA- or Ah value ?

[Vronsky]

Hi All,
This what my manual says about the minimum specs -lead acid- battery for my DF115A >

650 Marine Cranking Amps (MCA)/ABYC,
or 512 Cold Cranking Amps (CCA)/SAE
or 160 Reserve Capacity (RC) Minutes/SAE
or 12 Volt, 100 AH

This is a bit confusing to me as eg. lots of 100Ah batteries around have 760 CCA, so much more CCA than specified
But for CCA 512, most batteries are 76Ah so much less than specified

Which of these -contradicting- values is leading ?

THANKS,
V.

[Harper]

On your outboard, you don't need more than the MCA or CCA recommended. And there is no direct correlation between cranking amps and amp-hours. I think it depends on how much you expect to use your battery while the motor is shut down. Do you have a stereo that you play while sitting? Using a lot of lighting? Your fishfinder or chartplotter won't require much power from the battery, but some other accessories will use up your battery's amp-hour capacity, and that depends on type of entertainment electronics and wattage of lights used while sitting. I have a feeling that you're fine with buying the 512 CCA battery, but the 700+ CCA battery will certainly not hurt anything and will give you a cushion of the better Ah capacity. Above all else, you want that motor to fire up at the end of the day.

[Vronsky]

Thanks Harper,
This is going to be a new, second battery, for cranking and the bow thruster,
all other electric devices on board will be using the current semi traction battery.

I think I'll go for the 512 CCA range.

THANKS,
BV.

[tsturm]

Hi All,
This what my manual says about the minimum specs -lead acid- battery for my DF115A >

650 Marine Cranking Amps (MCA)/ABYC,
or 512 Cold Cranking Amps (CCA)/SAE
or 160 Reserve Capacity (RC) Minutes/SAE
or 12 Volt, 100 AH

This is a bit confusing to me as eg. lots of 100Ah batteries around have 760 CCA, so much more CCA than specified
But for CCA 512, most batteries are 76Ah so much less than specified

Which of these -contradicting- values is leading ?

THANKS,
V.

Cold Cranking Amps for starting batt..

Amp Hour rating for deep cycle, house / aux. / trolling mtr. etc two different worlds.