Powerquest....I just went through this whole senario and here's is what worked for me and everyone I hang with..My stock alternator from Merc was 65amp not enough not even close to the load I was drawing with an honest 2000 watts all at 2ohm load. this = 240 amp draw at FULL load, although reality is I was only pulling 120-140 amps under hard base and high volume. I was killing battery's and a standard lead acid battery takes hours to charge at 40 amps not to mention the battery will only accept so much at a time, especially if it is a deep cycle...So Heres the solution 2 2150 pcm ODYSSEY battery's 300.00 each with a 4 YEAR FREE REPLACEMENT, and call OHIO GENERATOR (google them)for there 180 amp alternator with a smaller pully so its charging at idle,, 500.00 The best part about these battery's is that they are AGM no acid and will take all the amperage you can toss at them From 0 to full charge in 20 min with the high output alternator with about 3 hours per batt stereo time, forget the optimas first time you kill them there done for good trust me 4 of them later send them back and follw this prescription and all problems are over gaurenteed...Ryan

True if thats the case where they are not getting recharged, How long and hard do you run on the motors before turning them off and running the system on the batteries?? In the case of a short recharge time, a bigger alternator will help......a little, but like posted above, you then need a battery designed to be charged quickly.

I agree with most all of the above, I was told by Interstate Batteries that the marine batteries (especially Optima's) like a slow charge at 2 to 3 amps) The tech said no matter what charge you throw at it, the battery will not except the "excessive charge". The gu was the owner of the franchise and he truly did seem to know what he was talking about. He recommended the automotive battery because it is designed to take a hit and recharge fast in addition to a high amperage draw like you would see in a car?

Its not my thoughts they were his. If I can buy reasonably priced batteries and have them last one year I can afford to buy new ones for the stereo in the spring? Don’t know.

Griff
If you have some time this weekend give me a call, maybe we can grab a drink and talk boats? My cell is 402-680-8751

I work 4-midnight all weekend and next. My next wknd day off is May 16 and I'll be on the river in the afternoon if the weather is even halfway decent.

Ive cancelled my Optima battery and am ordering an Odyssey 2150 battery....
Why pay $500 for a new alternator? I was on ebay and found a ton of marine high output alternators for $100-$140 and they are brand new.
http://www.db-starter-alternator.com...nators/Marine/
I'm going to order one of those as well.
Its amazing how quickly you can spend money just trying to avoid a stereo cutting out when you are sitting in the bay partying!!! $500 spent just like that!!! LOL!

Please post if battery takes care of your problem.

Powerquest, Yes please let me know if that solves the problem. I would like to see what works the best. Do you have the Mando alternator?

You may want to look into Lifeline Batteries. I run these on my house bank and they are great batteries.

http://www.lifelinebatteries.com/

Also, what i have is a 25 Amp Three Phase Newmar charger PT-25. and i couple it with my EU2000i honda to get the job done. If you end up getting a honda generator, you will need a AC to DC charger as the DC charger is only 7 Amp IIRC.

http://www.newmarpower.com/Phase_Three/Phase_Three.html

The other thing that i did was use a two input three output isolator 2-3-120, also from Newmar.

http://www.newmarpower.com/Battery_I...tegrators.html

This will take the output from both alternators and power three banks, either of the starting banks or the house bank. It works great....

If you see me on the water, let me know and i will show you the system.

Depends on the distance really. I have my amps forward and use 1/0 guage for the main feed. Long distances need bigger guage wiring due to the added resistance. After you have ran the system for a while check and see if the cables are warm. If they are you ought to size up.