What's your recommendation for a cranking motor battery for a Mercury 150 HP 4 Stroke? I can't find a manufacturer recommendation for CCA or MCA.

Google says :For a Mercury 150 hp 4-stroke outboard, you need a 12-volt marine cranking battery with a minimum of 800 CCA (Cold Cranking Amps) or 1000 MCA (Marine Cranking Amps)

Seems large?

Also, I'm installing a second battery to power my electronics (GPS, two live-wells, radio). No trolling motor yet. Maybe in the future.

Battery recommendation for electronics?

Thanks,

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Posted by geauxbrown

Louisiana

Member since Oct 2006

27579 posts

Posted on 6/16/26 at 5:07 pm to bagboy333

One of the things I had to learn about larger outboards was the large amount of power it takes to crank them. I’ve had situations where I could turn the key over, get tone and all my dashboard gauges and lights work but the battery not have enough juice to turn the engine over.

Don’t under power your outboard battery or you’ll wind up stuck somewhere.

I would suggest a minimum of 840 CCA

This post was edited on 6/16/26 at 5:09 pm

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Posted by TFLEX

Member since Jun 2023

388 posts

Posted on 6/16/26 at 5:19 pm to bagboy333

1000 CCA.

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Posted by Saskwatch

Member since Feb 2016

18267 posts

Posted on 6/16/26 at 5:44 pm to bagboy333

I have to get a new crank/house battery. Mine needs 750 cold cranking amps which is around a group 24 size. Likely going to step up to Group 27 AGM because same battery also runs GPS and Power Pole. Thinking of biting the bullet and go with X2 power based on research.

Mercury requires high cranking amps due to the alternator output

This post was edited on 6/16/26 at 5:45 pm

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Posted by Islandcat

Member since May 2011

315 posts

Posted on 6/17/26 at 7:35 pm to bagboy333

quote:
hp 4-stroke outboard, you need a 12-volt marine cranking battery with a minimum of 800 CCA (Cold Cranking Amps) or 1000 MCA (Marine Cranking Amps)

Yes this is correct. Just replaced mine Friday night. I bought a standard lead one at Walmart for 100. Although I think it’s recommended to go with an agm, I didn’t want to pay for one. I don’t have much electronics, so I am good with a regular battery.

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Posted by AlxTgr

Kyre Banorg

Member since Oct 2003

87619 posts

Posted on 6/17/26 at 8:04 pm to bagboy333

I have a 200 4 stroke. I switched to an Ionic lithium and couldn't be happier. I power all electronics and my power pole and end up over 95% charge at the end of the day.

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