Cranking battery

[alh7498]

What’s the best cranking battery and size to use on a 115-150 hp motor? Also are you looking for more cca’s or mca’s?

[CatFan]

CCA. MCA is a marketing gimmick invented to make the battery sound bigger.

[Jig_Man]

Your manual will give you an idea of size. However, if you have chart plotters they eat up juice so you may need to go bigger.

[CatFan]

Most engine manufacturers provide a minimum battery rating recommendation. For example, my engine battery rating is 1000 marine cranking amps (MCA), or 800 cold cranking amps (CCA).

My starting battery manufacturer provides both ratings for my battery which are 1370 (MCA), and 1150 (CCA).

Here are explanations for both ratings:

What is the CCA rating?

The cold cranking ampere (CCA) rating refers to the number of amperes a battery can deliver for 30 seconds at a temperature of -18°C (0°F) before the voltage drops to 1.20 volts per cell, or 7.20 volts for a 12V battery.

A 12V battery that has a rating of 550 CCA means that the battery will provide 550 amps for 30 seconds at -18°C (0°F) before the voltage falls to 7.20V.

What is the MCA rating?

The marine cranking ampere (MCA) rating refers to the number of amperes a battery can deliver for 30 seconds at a temperature of 0°C (32°F) until the battery voltage drops to 7.20 volts for a 12V battery.

A 12V battery that has a MCA rating of 725 MCA means that the battery will give 725 amperes for 30 seconds at 0°C (32°F) before the voltage falls to 7.20V.

In reality, manufacturers determine MCA by the rigorous process of multiplying CCA by 1.3 and then rounding to a number they like. No one ever measures it. It is completely a made up number.

[CatFan]

Your statements are not consistent with the specific MCA communication that I have had with several well respected battery manufacturers. In fact, they implied that all three of your statements are completely false.

Can you please cite the source of your information?

I worked with several battery manufacturers in my career as an engineer working on submarine and nuclear missile batteries and charging systems and am very familiar with all of the standard test methods employed in battery manufacturing. MCA is not a standard. There is no industry standard test method. You need to talk to engineers, not marketing people. MCA is a marketing gimmick, not a battery spec.

[SCOTT196]

You dont need a cranking battery. Get a group 31 deep cycle and use for your trolllng motor and also your big motor and accessories. I have done it for years, works great and saves you the added cost and weight of another battery.

[Rustym_22]

Mca is measured at 32° cca is measured at 0°. Mca is only higher due to the testing temp. And is essentially only marketing given most boats are not out on the water with temps below 32°.

[lpugh]

Your statements are not consistent with the specific MCA communication that I have had with several well respected battery manufacturers. In fact, they implied that all three of your statements are completely false.

Can you please cite the source of your information?

CatFan is far more credible than your sources as he has no dog in this hunt. Don't believe half of what you hear from manufactures. I am a old timer Master Auto Tech with 53 years in the field specializing in electrical and I cant think of a instance that I have ever took exception to his statements, I would consider him one of the very best sources in this subject matter

[billnorman1]

Mca is measured at 32° cca is measured at 0°. Mca is only higher due to the testing temp. And is essentially only marketing given most boats are not out on the water with temps below 32°.

At 0 degrees Fahrenheit most of us don't go out in "the boat". Quite true.

[bobcoy]

Not saying MCA is anything but marketing, but in my younger days there was about a month before freezup when the air was frigid and the water still open. Even the 2 cycles were pretty stiff turning over. If you have a barely big enough battery at MCA numbers you might want to pay attention to the difference between MCA and CCA. In northern climes(and probably anywhere) one should get a CCA rating at a minimum for your motors spec's. Too cold to take the chance of getting stranded, not too many people out to help in that situation. Bob

[ezfishn]

I'm confused over whether the issue is that no battery manufacturer ever does actual testing for MCA at that temperature or it is just a factor of CCA or different manufacturers have different factors for MCA...LOL If it is a bogus specification, why do they use it for the battery specifications for the engine requirements?

[CatFan]

I'm confused over whether the issue is that no battery manufacturer ever does actual testing for MCA at that temperature or it is just a factor of CCA or different manufacturers have different factors for MCA...LOL If it is a bogus specification, why do they use it for the battery specifications for the engine requirements?

I’m not much impressed with Mercury’s understanding of batteries.

[ezfishn]

I wouldn't limit that to just Mercury either...LOL

[Team Colibri]

What’s the best cranking battery and size to use on a 115-150 hp motor? Also are you looking for more cca’s or mca’s?

You look in the specifications of your outboard, then buy a battery that has at least the same CCAs (I agree with CatFan that MCA is a completely rubbish standard, more likely to confuse the buyer than help him) and at least the minimum Ahs recommended. The lather is sometimes overlooked, but since the regulators in outboards tend to be somewhere between ok and crap, using a small battery will just lead to overheating that battery. Typically you want at least 95Ah on a modern outboard that charges 30-40-50Ah.

Then look at LifePo4 for running the rest of the electronics on your boat. Make sure you are sitting when you check the pricing. ;)