What outboard motors do you have and what batteries do you use to start them?

[EdBerg]

I have been given conflicting advice regarding what battery I need for my boat motor so what motors (Brand and size) do you guys have and what batteries do you use to start them up plus any issues?

I have an Optimax 150HP Pro XS two stroke and according to the blurb I read on my motor, mine requires a battery with 800CCA or 1000MCA or 180AH, the last one I think is a typo and could be 180RC otherwise it would be a bloody big battery. The battery I just put on lay-by today is a Century Marine Pro 780MF, it does 780CCA so very close, it does 1000MCA so meets that requirement and if the last one is actually a typo then it also meets that requirement, please note that the blurb say "OR" in between each requirement and not "and".. so I believe that technically it should be fine. The battery also states that it is good for motors up to 350HP.

So if anyone has the same motor could you tell me what battery (make and size) is in your boat and if you have had any issues starting with it.

If anyone has a different largish motor please let us know your details as well 'cause it may help others who are confused and may be in the same boat ( Pun intended ).

Cheers
Ed.

[scottar]

200Ho E-Tec using a single Seamaster Gold MFM70 as a start battery. They start pretty easy as all the computer wizardry isn't required to actually start. The voltage for all that is generated within the first turn of the flywheel. They can actually be manually started with or without a battery.

[gazza2006au]

What i dont get with batteries is car batteries are rated in cold cranking amps where as a marine battery is rated in amp hours it gets a bit confusing as some manufacturers use the same engine in both automotive and marine

I have never understood the whole CCA thing

I have only ever bought one marine battery for the boats i gave owned it was a Seamaster from BIAS boating cant remember the AH rating but what i have noticed is a majority of the marine deep cycle batteries seem to be 120-130AH in size the bigger deep cycle 180-200AH seem to be classified for home solar power

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[scottar]

Some info on CCA and the other various ratings in the FAQ page here.

https://www.rjbatt.com.au/faq/

[Paul071978]

CCA is cold cranking amps at temp -18C and MCA is at 0C. Your battery selection is fine however for venturing offshore say more than 5NM I would highly recommend a dual battery system if you don’t have already. Also it’s good maintenance annually to check and clean both pos and neg leads where connected to battery and engine with wire brush or sand paper to remove corrosion for a nice shiny metal surface to reduce resistance. Even partially corroded cable lugs can reduce your battery capacity by 50%

[gazza2006au]

Thanks Scott i wasnt aware batteries were tested at different tempretures but it would explain how batteries dont go bad in locations with snow

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[EdBerg]

Thanks Paul071978: I also was wondering why the different ratings, I suppose if the temp was -18 chances are you wouldn't be going any where anyway as you would probably stuck in ice.

I have always had dual battery systems in the past except for this boat due to finances being a bit low and the size of the boat itself. This is the smallest boat I have had in probably 30 years, but I might have to see what I can scrounge up, even contemplated taking the old battery as it isn't totally 100% crapped out as it still started the boat.

[shakey55]

Marine Batteries are rated in CCA as are all motor starting batteries
IMG_6738.jpg


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[Noelm]

I have never been a battery snob, I just buy what I need at the time, currently I have a Yamaha 50 that I needed a skinny battery to fit in a certain space, got one at Auto one, some cheaper brand they sell, it's 3 years old now. I also have 2X 90hp Suzuki's that one has a Century 580? that's about 6 years old, and the other has a cheap brand that's a bit bigger and it's about 4 years old.

[ranmar850]

What i dont get with batteries is car batteries are rated in cold cranking amps where as a marine battery is rated in amp hours it gets a bit confusing as some manufacturers use the same engine in both automotive and marine

I have never understood the whole CCA thing

I have only ever bought one marine battery for the boats i gave owned it was a Seamaster from BIAS boating cant remember the AH rating but what i have noticed is a majority of the marine deep cycle batteries seem to be 120-130AH in size the bigger deep cycle 180-200AH seem to be classified for home solar power

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have a look at my reply to your post in the "other" thread. Difference between MCA and CCA is that the MCA rating is done at a higher temp. Car batteries (CCA rating) are commonly exposed to much lower temps than boat batteries (MCA rating)

[ranmar850]

When I outfitted the new boat ( 150 Merc 4-stroke)I used 2x 800 MCA ( IIRC , rating required for that motor) connected via a VSR and emergency bridging switch. My reasoning was that I would swap between Start and House position every year or so to rotate the duty. Of course, I later added a fridge, which changed matters a bit. The start-rated battery does ok overnight, and is fed by a 120W solar panel on the roof, feeding directly into the house battery via a solar regulator. After 2 1/2 years and 585 hours, simple setup, no problems.
When time comes for replacement? I'll probably go for a 105a/hr deep-cycle on the House position.

[CT]

Century Marine Pro 780MF, it does 780CCA so very close, it does 1000MCA

My specs required 1000 MCA. I got the same battery and 12 months on it still starts fine. Merc 225.

[inveratta]

150hp Merc 4 stroke..I take a pretty basic approach....have tractors 4wd etc and boat...run em all off the same battery type..century 770CCA.just wait for them to come on special as they do from time to time.In the boat two of, one as back up and running stuff with three way switch ..boat builder suggested do it this way...
a larger boat with more sophisticated electrics may need more bling but this has worked fine for years..

[Ronje1]

Outboard motors have less compression that 4wd/tractor (diesel) therefore cranking amps to combat lower compression found in o/b motors is less. Not many diesel outboards around.

CCA (cold cranking amps) spec is measured at much lower temps than what we experience in most places in Aus.

The cranking amps spec at the higher temps that we normally experience is quoted as MCA (marine cranking amps) and higher than the Cold Cranking Amps figure when measured in respect of the same battery.

Cranking batteries are manufactured differently to marine batteries and both of them are different to deep cycle batteries both in construction and purpose.

You can get away with using any battery for any purpose for a while but in the long run, misuse will catch up and can result in failure at the most inconvenient time.

Batteries ain't batteries, Sol.