Cranking amps (CCA)

[Rum_Pirate]

The battery requirements are detailed in the owners manual

View attachment 149937

In this case for a Yamaha 9.9 electric start 4 stroke max CCA is 245 -433.

Googled "what happens the maximum CCA rating is exceeded" and could not see a single reason against using a higher CCA battery.

So why is there a NOTICE : 'Do not use a battery which exceeds the maximum CCA rating' ?

 

[ylop]

I guess theoretically a battery with greater amps could make things worse if there was a fault - but I think you are worrying about nothing. You could always add a massive 400A fuse and then the battery would not be able to supply more that the spec.

 

[AngusMcDoon]

I had that engine for 15 years connected to 150 Ah of installed batteries (they were starting and house batteries) and a total CCA way in excess of the manual's maximum. Nothing untoward happened.

 

[Rum_Pirate]

OK update I managed to call Yamaha Corp in the USA.

A lady there, Pam, was helpful.

Advice received:

No damage will occur but I would be unnecessarily spending money I didn't have to if i purchased/used a battery with greater cranking amps than recommended.

In my case (gave her the serial number) the recommended CCA is 323 -520 CCA.

So now you know. ?

 

[Tranona]

That is not necessarily true as you will find out when you look at specs against price.

However, the demands of the starter are modest and as several said on your other thread a basic car battery of 45-70Ah capacity will do the job. only need the larger if you have domestic demands or instruments and limited charging. You will need to supplement your charging in addition to the alternator with solar or mains charging.

 

[jamie N]

The starter is requiring a Voltage and amps to energise it. Having massive CCA will only cause damage by continual operation of the starter on a 'dead' engine by an idiot owner.
Having 'available' CCA at the right VDC, has never destroyed anything.

 

[Momac]

I think its best to have a starter battery with plenty of CCA.
That means if the battery capacity reduces with time it will remain serviceable .

 

[jamie N]

The analogy is similar to having a very large petrol tank on a small car; the car won't run any differently providing that you adhere to the service schedules; i.e don't crank the engine for over 30 seconds or whatever the manual states.
RTFM.

 

[AngusMcDoon]

i.e don't crank the engine for over 30 seconds or whatever the manual states.

Not starting is a rare problem on those engines. Most reliable starting outboard I've ever had. Started every time within a second or two for fifteen years of use as the main engine on my boat.

 

[Refueler]

The starter is requiring a Voltage and amps to energise it. Having massive CCA will only cause damage by continual operation of the starter on a 'dead' engine by an idiot owner.
Having 'available' CCA at the right VDC, has never destroyed anything.

Why ????

Starter motor demands volts / amps as determined by the work it has to do to turn over the engine ... the demand does not change based on battery used unless battery cannot supply the demand ... then starter does not get full demand.... in fact it would likely cause battery damage.

You could have 1000A CCA capable battery and starter will still only draw the amps it needs ....

 

[jamie N]

Why ????

Starter motor demands volts / amps as determined by the work it has to do to turn over the engine ... the demand does not change based on battery used unless battery cannot supply the demand ... then starter does not get full demand.... in fact it would likely cause battery damage.

You could have 1000A CCA capable battery and starter will still only draw the amps it needs ....

If the CCA is too low, then the engine won't turn over for very long. If the CCA is very high, and the owner's a 1/2 wit, there's a danger of the fool turning over a non-running motor for a long period of time, potentially burning out the starter, or screwing up the ring gear; whatever.
Having a huge CCA isn't the problem, nor did I intimate that it was, so I believe that you've misread my posts 6 & 8?

 

[Refueler]

If the CCA is too low, then the engine won't turn over for very long. If the CCA is very high, and the owner's a 1/2 wit, there's a danger of the fool turning over a non-running motor for a long period of time, potentially burning out the starter, or screwing up the ring gear; whatever.
Having a huge CCA isn't the problem, nor did I intimate that it was, so I believe that you've misread my posts 6 & 8?

Misread ???

Having massive CCA will only cause damage by continual operation of the starter on a 'dead' engine by an idiot owner.
Having 'available' CCA at the right VDC, has never destroyed anything.

How can that be misread ??

 

[mil1194]

I think its best to have a starter battery with plenty of CCA.
That means if the battery capacity reduces with time it will remain serviceable .

I’ve always tried to buy the biggest/most powerful battery that will fit in the hole for exactly that reason.

 

[noelex]

OK update I managed to call Yamaha Corp in the USA.

A lady there, Pam, was helpful.

Advice received:

No damage will occur but I would be unnecessarily spending money I didn't have to if i purchased/used a battery with greater cranking amps than recommended.

In my case (gave her the serial number) the recommended CCA is 323 -520 CCA.

So now you know. ?

One general consideration is the IC (interrupt capacity) rating of any fuse protection incorporated into the design. A battery with a larger CCA rating requires fuses (or circuit breakers) that have a higher IC rating. I have no idea if this applies to the Yamaha, or if the outboard even has any circuit protection, but it does explain why a manufacturer may sensibly limit the maximum permitted battery size in some cases.

Bigger is not always better .

If the the advice from Pam was correct, this concern obviously does not apply in this case.