Marine batteries

Brian - Marine batteries are usually built to a higher standard of durability than regular batteries, thus the big following.
I think you'll find most of the better-known manufacturers have marine batteries as part of their product lineup.

I use the major well-known brands, and make sure they have a long warranty. If a manufacturer can't guarantee his battery for 3 yrs at least, he hasn't got much confidence in it - and neither do I.

My favourite at present is Supercharge Gold for starter batteries. I've currently got a Supercharge Gold in the ute, that I purchased in March 2004 - and it still starts the ute hot or cold, like the day I bought it!

Supercharge have a marine line of batteries, as do Exide, Century, AC-Delco, and probably a dozen more brand names than I can't recall at present.

You need to select your battery for its intended use - use a starter battery in automotive applications, and deep cycle batteries in caravans and applications where you're using it power fridges and accessories.

Cheers, Ron.

Been a common thing to do since auxillary batteries first went under bonnets of 4wds.
I use the Century N70ZM - 100Ah and $153:
http://www.batterydiscounters.com.au/marine.html

Other benefits are the better terminals with both post and wingnut, and its nice to have a battery where you can top up the water.

"Marine" batteries are a rugged construction battery, some manufacturers also sell a battery under a "4wd" or "earthmoving" badge.....one major manufacturer sells the exact same battery with a different colour case as a marine battery and a 4wd battery...interesting in supercheap auto the 4wd version on the same shelf is more expensive...hmmm

Marine batteries generally have better cranking better self discharge and better deep cycle performance than a similar standard battery.

if you want to get into the detail go onto one of the battery companies that actually puts ups some specs and compare different batteries of the same size.
The supercharge site is not bad and contains a number of different battery types of the same size...and they show a fair bunch of specs.

Most batteries intended for auromotive use do not come with an AH capacity specified....why.....good question....but you can get some idea from the reserve capacity.
From the reserve capacity you should be able to extrapolate the C10 amp hour capacity.

so what makes a marine battery different.
heavier construction all round..
heavier plates, better supported
glass mat between the plates to controll the electrolite and dampen vibration.

if it is a sealed maintenence free battery, it will have many of the technological advances that allow AGM to exist...they just run more electrolite than an AGM or other "starved elecrolite battery'.
That means
modified electrolite, glass mat between the plates and calcium in the plates

the modified electrolite and calcium in the plates improves just about every measure of battery performance, in addition to allowing the battery to be sealed.

I too run "supercharge seamaster gold" in the 4wd in both cranking and aux positions..and in my boats....Id run one in my work ute..if there was a seamaster that would fit.

a M70 size seamaster gold......same size an an N70 typical of many 4wds and light trucks should cost you around $200....less if you shop well..seem they have increased their warranty from 24 months to 3+years.......as an indicator of their confidence in the gold...compare the warranty given on other batteries in their range.......their standard seamaster screwtop battery only rates 12 months warranty

As has been mentioned the seamaster gold is one of the very few sealed batteries that you can actually top up....once out of warranty...they are a proper valve regulated sealed lead acid battery...its just that the vent valve assembiles can be screwed out once the top sticker is removed.

I know a lot of people push deep cycle in aux batteries.....If like me you wish to crank or winch off your aux...you are better off with a cranking battery.

Consider too that the marine batteries have far better deep cycle tolerance than a standard battery....maybe not as good as a "proper deep cycle"

But if you run marine batteries you can afford twice as much capacity( deep cycle AGM is typically twice the price).....so for a given loading..you cycle half as deep any way.

The other benifit of running cranking battery is that they will tolerate having the charge current hammered into them.....many deep cycles will not....this may result in the need for a DC to DC charge to limit the charge current.

As for the comparison with AGM.....sorry I believe that AGM is very much oversold....all the good sealed marine batteries use all the technology that AGM does...but they just run more acid...more acid makes them more tolerant of heat, higher charge rates and overchanging.

lost of people go out and pay top dollar for AGM and or deep cycle..and because of ignorance or inattention to their battery, manage to kill those batteries in very short order.
Never benifiting from paying twice the price or more for their batteries.

NOW if you have a serious battery system and are very seriuos about your DC supply and manage it well.....you may well benift from spending the extra $$$ on exotic batteries.

But for most of us that just want to hold up a fridge and some lights for a day or two then charge up as fast as possible.....marine batteries may well be the go.

cheers

Just happened to be in a Repco store today, and was looking at batts, and checked out their marine hybrid type battery...730CCA......100 a/h.....$230..

On the vent caps cover was Yuasa !! If it was in fact a rebranded Yuasa, then I'd be happy to part with the hard earned.......have had excellent runs out of Yuasa batts as OE batts in cars and 4wd's from new !!

Thanks once again to everyone who have been so helpfull . My situation is as follows
I drive an old Tojo HJ61 and it has a twin battery set up but they work as separate systems , the cranking battery is new and should be fine for a long time . The other battery is stuffed and is used to run an Engels fridge ( not sure of the actual size but is a portable type and i think uses about 2amp hours ?? ) So what i'm thinking is i will purchase a deep cell battery for this aprox 100 ah but not a AGM type because of their supposed dislike of heat which is always there under the bonnet .
Then there is the need in the caravan for a decent sized deep cell battery ( at least 100 odd ah ?? ) perhaps i could go an AGM in there ?? Ok so what i have at present to charge a new battery in the van is charge from Tojo via an Anderson plug , solar panel on roof of van but not sure the size , maybe 80 watts , and i do have a new Honda 2kv generator for backup which has an inbuilt charger but noticed that the power lead for the charger is very short , so in an emergency to charge up the van battery i would almost have to take it ( the battery ) out of its " home " under the seat in the van to charge it . All is good if i wanted to charge the aux battery under the bonnet as the length of power cable required is not so great . Hope my queries are not too obvious!

Brian,

Just my take. A cranking battery is designed to put out heaps of amps for a short time, typically 3-400 to start the engine. A deep cycle either AGM or wet cell is designed to put out a smaller amount of amps but for much longer duration to run our fridges, camp lights etc. This is why the 2 have their ratings expressed differently. CCA v AH.
It amuses me when people say that marine batteries are built to take more of a pounding. How much more of a pounding could a battery be asked to take then spending days on end enduring the dreaded corrugations, rock strewn creek crossings and washaways encountered on many of our favourite bush tracks. Yes boats can and do hit waves that feel like they have rocks in them but are still made of water.
As far as I can see the primary reason to go for a "marine" battery is to try and get the best of both worlds, sort of a compromise. If space is restricted then one or these is probably not a bad solution in as much as it will perform both functions to a degree.
As I said just my opinion, if you have the room for 2 batteries use a cranking type as a starter, winching battery and a deep cycle either AGM or flooded for powering your fridge and other camping gear. If there is no other mounting option than under the bonnet I would use a wet cell type. You can always replenish the lost water easily. If you can put the battery well away from a heat source such as the engine an AGM will always be my choice.
Next of course is your charging regime. No lead acid battery likes to be discharged below about 50% repeatedly and no battery likes to be left discharged for long periods. With the options you have with the vehicle alternator, especially an older type without all the reduced charging voltage algorithms, a solar panel and your genny as a last resort managed properly you should be ok.
Just not sure about using the 12v output to charge your batteries. I would use the 240v and a proper battery charger.

Cheers
Pop

Anyone would think these experts live, sell and manufacture batteries for a living......

Have a look at these links

http://www.aussiebatteries.com.au/free-ebook/

http://www.exidebatteries.com.au/battery-range/marine-leisure

https://www.google.com.au/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#newwindow=1&q=difference+with+marine+and+deep+cycle+batteries&spell=1