battery question

clifford69

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Joined
Feb 21, 2004
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5
Hi I need to replace my starting battery in my boat. what's is the differnce between an automotive battery and a marine starting battery. The battery will be used srictly for starting the boat nothing else. all other electronics will be ran off one of the deepcycles. thanks
 

ZmOz

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Aug 13, 2003
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3,949
Re: battery question

Marine batteries are a little bit more heavy duty, and can handle a little bit more discharge than a regular battery. Also they usually have higher cranking amps. If you're not going out to sea, I wouldn't waste my money on a marine battery. An automotive battery will do the job just fine...there's been one in my boat for 5 years now and it still works just fine.
 

Solittle

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Apr 28, 2002
Messages
7,518
Re: battery question

A lot depends on the battery and the motor. You don't need much to start a 9.9 hp but a tad more to start a diesel.
 

Oldsaltydog

Petty Officer 1st Class
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Jan 27, 2004
Messages
322
Re: battery question

As I understand it, a marine battery is constructed more sturdily in order to take more pounding than a car battery. The next point to consider may be the type of ride your boat has and the kind of sea conditions you motor in. The cost difference does not seem to be major.
 

18rabbit

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Nov 14, 2003
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3,202
Re: battery question

As I understand it, a marine battery is constructed more sturdily in order to take more pounding than a car battery
What do off-road vehicles use?
 

Hooty

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Oct 2, 2001
Messages
4,496
Re: battery question

After you get your new battery, invest in one of these, leave it hooked up 24/7 when your boat is not in use. <br /><br /> Battery Minder <br /><br />c/6<br />Hooty
 

ZmOz

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Aug 13, 2003
Messages
3,949
Re: battery question

Originally posted by 18rabbit:<br />
As I understand it, a marine battery is constructed more sturdily in order to take more pounding than a car battery
What do off-road vehicles use?
Most use Optima gel batteries because of their off road lights and winches. That would be a GREAT choice for a boat too, but they are $100+.
 

MajBach

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Jun 21, 2003
Messages
564
Re: battery question

--------------------------------------------------------------------------------<br /> As I understand it, a marine battery is constructed more sturdily in order to take more pounding than a car battery <br />--------------------------------------------------------------------------------<br /><br />What do off-road vehicles use?
Boats don't have shocks. Marine batteries ARE of sturdier contruction. Don't know about higher cranking amps though.
 

clifford69

Recruit
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Feb 21, 2004
Messages
5
Re: battery question

when I compared the two I could get an automotive battery with alot more cranking amps than a marine battery and for significantly less. thanks for your input
 

Major Woods

Petty Officer 1st Class
Joined
Jun 7, 2001
Messages
317
Re: battery question

A marine battery has a thicker casing often with internal supports.<br />The plate construction is often (depends on manufactureer) heavier also with internal support. The seperators are thicker to protect against premature wear and short.<br /><br />QA supervisor in a battery plant for 6 years.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: battery question

In the past I have used car batteries with no problems and I ran in some of the ruffest waters with them. I don't doubt the heavier plates helping the battery, but this has just been my experience for what it's worth. BTW, I do have a marine starting battery now, but only because they were so close in price, there was no reason to pass it up...
 

18rabbit

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Nov 14, 2003
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3,202
Re: battery question

The presumption is marine batteries will see deeper cycles for both starting and deep-cycle battery applications. For this reason, both anode (+) and cathode (-) plates are usually heavier (thicker). MW is correct, better quality marine bats have the plates supported from the bottom. In car batteries, the plates are suspended and the space below them is a ‘crud collecting’ area for the conductive materials that sheds from the plates during normal use. The best quality marine batteries have the plates encased in a non-conductive material (fiberglass with holes) to help retain the initial integrity of the plates. Because material cannot shed and sink to the bottom, the plates can also be support from the bottom as well.<br /><br />Unfortunately, your average marine starting battery is nothing more than a car battery with thicker plates (deeper discharge) that are not supported from the bottom. In this case, you might as well save your $$$ and use a car battery with more reserve cap…unless you have engine starting problems…then I wouldn’t go out with you no matter what battery you had!<br /><br />Battery cases are not such an issue anymore. They are goooood! :) They’re all pretty much the same. The plates are not designed to move inside and nothing should be crashing into the outside of your battery. Some marine bat cases are double walled…but those batteries are usually found in the $1200.00+ range and you can remove/swap each individual 2v cell…not something you find on your average jon boat. :) <br /><br />Fwiw, the most industrious use of off-road vehicles (US Army) uses Deka AGM batteries, model 6-TLFP, discharge capacity at –40 deg F is 350-amps, 0 deg F is 625-amps, reserve cap at 80 deg F is 180 minutes. There are probably other manfs of this battery to those specs.
 

quantumleap

Master Chief Petty Officer
Joined
Feb 16, 2004
Messages
813
Re: battery question

Don't compromise on a battery. There is nothing worse than being stuck on the water. Compare the cost of a battery to the rest of your boating investment. Go to wally world, their marine starting battery is only 10-20 bucks more than an auto battery. .02
 

18rabbit

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Joined
Nov 14, 2003
Messages
3,202
Re: battery question

At $10-20 more, it IS essentially an auto battery. You can get a bigger bang for your buck by putting that marine battery into your car. :)
 

ZmOz

Captain
Joined
Aug 13, 2003
Messages
3,949
Re: battery question

Yeah, the cheap marine batteries aren't really worth the extra money. Like I said, if you're going to be out at sea, you should not only get a marine battery, but a top of the line one. But if you're on a public lake/river, don't waste your money. My boat has a 5 year old cheap, store brand auto battery. Still works as good as anything else, and my boat rides really rough in even a little bit of chop. (plus it's been abused all that time by my inline 6's crappy high voltage charging system)
 
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