battery stolen

alumapompano

Cadet
Joined
Jul 8, 2013
Messages
16
I just had my battery stolen out of my boat.. I need to know the cold cranking amps for my 1984 70 hp Johnson seahorse.. I had a diehard but forgot the one I had please help.......:grumpy::blue: serial number -J70EL CRD
 
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Georgesalmon

Lieutenant Commander
Joined
Apr 14, 2012
Messages
1,793
Re: battery stolen

just get the largest CCA you can afford and will fit in the space or box you have. The motor will only draw what it needs so bigger will not hurt anything.
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
Re: battery stolen

Just about any marine battery should start that 70 hp. They start at about 400CCA, but it also depends on what accessories your running. It may depend more on the size of your battery box. A group 24 battery is 11" long, were a group 27 is 12 3/4" long.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: battery stolen

Agree with George. Your engine does not take a lot of cranking amps. At least 300-360 cca. Most "starting" batteries today are rated much higher. Many deep cycle batteries are not considered "starting" batteries unless they are premium ones, and state they are rated for starting.
 

phillnjack2

Ensign
Joined
Apr 30, 2011
Messages
918
Re: battery stolen

well sorry to say this but the advice above about 360 cca is wrong for a 70hp omc.
I had to buy a new battery myself and looked deep into what really is needed to get the starter motor turning at what it should be.
you need around 600 cold cranking amps or more.
a average car battery is not enough, get one meant for a diesel and your problems will be fine, as most diesel car battery's are around 600 or more.
the battery I just got is a Banner Power Bull car battery 12V 72Ah 660A , this turns over my 3 cylinder 60 perfectly well.
the other one I tried was a 500 cca and did NOT spin the engine as fast by a long way and the starter will get too hot and possibly
burn out the windings a lot quicker.

now unless your going to leave the battery on the boat a long time and use it like a cabin cruiser there is no point in looking
around for specialist marine battery, these cost far more than they are worth and will not last long enough to warrant the extra price.
Now do NOT get a gel battery as this is no good for the electrics on your engine, great as a no spill but bad for the electrics.
you need a proper lead acid battery for everything to run smooth.
but a 300 cca battery will not be much good and you will buckle the battery plates very quickly with such a small battery.
the 60 and 70hp omc starter motors take a lot of current to get them spinning up to the right speed.
also if you have power trim you need something with plenty of power in reserve as power trim takes a lot of power from the
battery as well.
also a heavy duty battery will have stronger plates and will take all the knocks associated with boating..
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: battery stolen

The service manual says, 360CCA (465 MCA). This is a minimum.
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
Re: battery stolen

Marine batteries have the better supported plates to take the lumps and bumps of boating. You only need a deep cycle battery if you drain it below 70% on a regular basis.
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
Re: battery stolen

get State Farm to pay for 600 to 700 cranking amps. I like marine deep cycles with cranking amps in that range -- good for starting and storage, as well as use of electronics when out on the lake, but know there is mixed opinion on the need for deep cycles. #2 post is good advice.
 

phillnjack2

Ensign
Joined
Apr 30, 2011
Messages
918
Re: battery stolen

deep cycle batteries are not good for outboard electrical charging systems.
and 360 cca isnevergonna swing a 70hpo omc triple any good at all, been there tried it and its a bad idea.
just pullking the juice through gets the starter motor a lot warmer than it should do.
with a much larger more powerfull battery the starter motor stays cooler and turns quicker/faster.

as for marine batteries, the plates of marine batteries are supposed to be thicker yes, but they are not any thicker than those used in heavy duty car batteries used for diesel engines.
Many years ago it was the case that marine batteries were different, but since the diesel engines have come on a long way so has the plates in heavy duty batteries.
if you get a 70 amp h heavy duty battery with around 650 cca and weigh it on a scale, it will be around the same if not more than a
so called marine battery, a normal car battery of same dims and specs will be lighter by a few pounds.
I asked at exide batteries about this very subject, and was shocked to hear that the marine batteries are just heavy duty batteries on the inside with nice jazzy stickers on the outside.
the actual specs are the same.
Do not confuse a heavy duty with a normal petrol car light duty, the plates are much stronger in a heavy duty battery.

most speedboats have the battery in the vary back of the boat next to the transom, this area don't take as much of a battering as you might think, unless we are talking offshore high speed racing in waves.
Then its down tousing optima accumulator types of battery !! ( yes I know a battery and accumulator is different,)
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
Re: battery stolen

never had an OB charging system problem (none that I was aware of) with deep cycles, but phillinjack2 has some technical research going on there, so will defer to him or others on that. Diesel batteries are heavier duty, according to my car mechanic, consistent with phillinjack2's post -- but can't verify that except from use -- and purchase. They cost more, and they are big batteries (grp 30 or 31, I think). If you want to do some online price comparisons, I suggest the Sears site. Use the ff. car info, if you like: 1985 Mercedes 300SD. That should get you some prices.
 

phillnjack2

Ensign
Joined
Apr 30, 2011
Messages
918
Re: battery stolen

yeah I did read that in number 7
but I have found that anything under a 600cca to be a bit on the slow side for the starters.
I appreciate the manual stating 360 as a minimum, but most manufacturers of batteries do like to brag up their batteries and more often than not the 650cc is really only a 500cca if your lucky, a 70 amp h is realy a 60amp h again if your lucky.
like most things its rated in ideal situations, never like the real environment its put into.
with boats they are always in a damp situation that is often cool (or cold in the case of the uk ).

batteries are just heavy black boxes full of witchcraft ha ha
 

daselbee

Commander
Joined
Jan 20, 2009
Messages
2,765
Re: battery stolen

I gotta agree with Phill. The spec for a V6 from the book is also right around the same 360cca.
That just cannot be correct. I couldn't believe it when I read it.
I would get a 600 or greater cca battery.
 
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