Pretty much familiar with the basics but having trouble getting several questions answered on the net-i wish the boating forums were as active as this one.....but anyway:
I have a 1998 Mercury Salt Water Series 200hp 2 stroke (LOW hours-I ain't buying a new one ).
Is running two 24M starter batteries each rated at 1000 MCA enough to start it and run an occasional burst from a rule 500 gpm bilge pump and the occasional spot light? Not running any electronics as my VHF and GPS are hand held. Before they got stolen, I had a pair of 27M's at 1000 MCA each and I felt that I has a good amount of overkill, but in reading some of the internet recommendations for today's 200hp Mercurys now they say 1000 MCA is a minimum. I wonder if this is because of all the new computers in these new fangled engines and am hoping that someone who knows what they are talking about chimes in.
Secondly, are the AGM's worth the added cost over the flooded batteries for starting purposes?
Third, When I have the switch at "both" am I getting 2000 MCA's out of the bank. They are in parallel (meaning that both positives go to the positive terminal in the selector switch and the negatives are linked battery to battery to switch)

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Forum consigliere

I run group 27 marine deep cycle from Interstate.

Mine is a 2004 150hp Evinrude DFI.

Prior to a repower, it was a mid '80's Suzuki 150SS.

I don't think AGM is needed. In a motorcycle, perhaps. I run my boat in the Pacific Ocean around Half Moon Bay and Pacifica, it gets rocked a lot and the batteries never suffered for it.

Oh, and I run a multi function sonar/GPS and the radio with it.

Your CCA parallel question is you will not get 2000MCA. You will get 1000MCA for twice as long.

There are a couple battery manufacturers in this country and they label for everybody, even Walmart. I would call West Penn Manufacturing in Reading PA and ask them your questions. I have used them before for technical stuff. They have design and application engineers. They are good people, and they can explain the glass mat battery vs. Lead acid, benefits and life expectency. Also your pump question. Hope this helps.....Pete

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Pete
I ain't no fortunate son

My mid 90s 200hp Evinrude Looper worked fine with a Wal-Mart starter battery and 2 trolling motor batteries. I replaced them every 4-5 years and kept jumper cables but can't remember ever needing them.

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God spelled backwards is dog.

The Hull Truth is pretty active, if you can't find the answer
just by searching.

AFA the 'current' standard for a 220 HP Merc, that's going to
be a four stroke motor. I'd think your 2S is easier to turn over
than a 4S version.

Walmart batteries are made by West Penn Mfg. I have alwas heard good comments about Walmart marine grade

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Pete
I ain't no fortunate son

I have a 2006 Nautic Star 2200 with a 225 Yamaha 4 stroke. Put in two size 27 Optima AGM batteries for the trolling motor when new. Finally had to change them out early last year. I changed the starting battery to AGM in about 2011 and it's still in there. I think the AGMs are worth it.

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Foster Positivity.

Buy Deka or similar quality group 31s.
When the batteries are paralleled the engine will start with less of a voltage drop and twice the amperage..... quicker/easier than with one alone...... which should be sufficient to start the engine properly!!!
Proper caliber in batteries.
Once you’re done running it’s prudent to isolate one battery for just in case..... as my boy and his fishing mates learned.

If you chose flooded batteries make sure you can check/maintain the water level.

We hunt with fishing rods in South Florida.
Scuba gives them a fighting chance.

Gary, You of all people should know better about owning a boat....

Borrow your neighbor's boat, then your problem would be solved.


WuzzFuzz

Thanks a lot Overheard my son one time say he doesn't need a boat cause his dad has two.

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Forum consigliere

A mullet rifle from the canal bank and you wont need batteries.

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Dum vivo cano

Can I borrow one of them???? And not the one that needs batteries.


WuzzFuzz

The boat has sat up for a couple of years. I realized I had bought it in 2003 so the tires were at least 15 years old so three (spare)new tires. Then the batteries had gotten stolen so two new batteries. Then 4 hours cleaning it. Now, after 4 hours of cleaning, a few more hours running around getting tires and batteries (not to mention close to $600 for the batteries and tires) NOW I can take it to the mechanic so he can drain the tank, change the impeller and fuel separator and get the *^%&ing thing running. My wife and kids have been on me to slow down and start enjoying myself. It took a poker buddy's wife suddenly dying of an unexpected heart attack and a colleague dying of a sudden heart attack to finally make me realize that I better start enjoying things while I still can.

I had forgotten just how much "having fun" with a boat costs

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Forum consigliere

Ok, one last suggestion....If you want to slow down and enjoy life a little....

If you like the water, and you like boats, take the Mrs. on a nice cruise and you will be able to enjoy all three at the same time.


WuzzFuzz

Taking care of a boat... Bring Over Another Thousand... ain’t much different than taking care of several very large safes full of Privateer’s tools.

When I was asked if the yacht was missing/needed anything else I replied... trap or skeet on the aft deck?
Wiring a boat correctly saves watching the flames from the shark infested waters of the Bermuda Triangle.

Too Much Food..... Cruise Ship Diet?

Many good answers. Will throw in my .02.....
I experimented with AGM batteries in my boat as the dedicated source for electronics and trolling motor.
I also had installed a 'loop charger', meaning, when the OB's alternator was through charging the starting battery, the AGM would receive charge. Great way to keep it topped off, no?
Wrong. Seems AGM's REALLY don't do well with frequent charges from being only partially down.
Essentially, the AGM got 'cooked' and had a very early demise, considering it's cost.

Good luck, you will get caught up. For awhile.

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Ret'd LEO
SWCA #2275

Deka batteries are great. Again, they are West Penn batteries in Reading , PA

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Pete
I ain't no fortunate son

Batteries need to be exercised. putting one in that is either too big, and does not work hard enough, or giving it a charge memory with little usage kills it. I buy for my car, the smallest battery I can. Usually OEM standard. Want to replace your battery all the time?? Then put a super big Die Hard in your car that is 2X the size of the OEM battery, and you will sulfate it in 2 years. Then you will say the die hard is junk. Nope, as the Rolling Stones say" It's the Singer, not the song"

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Pete
I ain't no fortunate son

I'm most of the way through installing something similar, in my
rig. Lead acid all around, for start & trolling batteries; using a
cheap (relative to marine products) solar charge controller, to
add trolling battery to alternator/start battery circuit. May work
well, or may burn down the boat...

Batteries and Boats.
Spent a lifetime playing with those items.
Will condense the 1200 page “latest battery study” hopefully tomorrow as i have to go play with “Jet Lag”, a 40’ Class Ketch today. So much for retirement.
Gotta find a way to pay for 460 Ammo!