Dual Batteries

I'm planning on reinstalling both batteries like I had last year. The way I did it last year was the "house" battery was only connected to the stereo and amp and it wasn't connected to the engine. I threw it on the battery charger at home. This year I'd like them both to be able to be charged by the engine. Here's my set up:

Starter Battery:

Marine Starting (24 Series)
625 CA
500 CCA

"House" Battery":

Dual Purpose (Starting / Deep Cycle)
875 CA
205 Reserve Capacity

**Goal**

Engine always charges batteries individually when the engine is running with priority to the starting battery. When engine is off the drain is always on the "house" battery, or never drains the starting battery below a certain level.

I've started reading about battery switches, relays, voltage sensing switches and voltage sensing relays. It kind of sounds like I should use a switch and VSR, but I'm not sure.

Can anyone provide some feedback or share your setup?

Okie,

On my previous boat, I had a system setup using an isolator, I chose the "Hellroaring" one.

It is SUPPOSED to isolate your batteries electronically - so they can both be
charged, but used independently. The one I used has a switch I installed under
the dashboard that would allow me to "combine" the batteries if I needed it -

Take a look - I am not sure it was the BEST setup, but it seemed to meet my needs
at the time.

In the Supra, I have an onboard charging system that gets plugged in at home -- but
I don't drive my stereo like some on here do.

A Perko or other type switch like Todd recommended is ideal to select which battery is opened to the alternator.

Okie
All you need is a battery Isolator. Since you are using the batteries for two separate operations the isolator will connect them to the alternator only when the alternator is charging. When the engine is off the batteries are totally separate. You can run the stereo
until it's dead and still have a full charge for starting.
Check out donrowe.com the 95 or 120 amp units should be fine depending on your alternator size. They are super easy to wire up and only cost $39-57. Best of all the system is totally automatic no switches no maintenance.

here is a thread in the moomba forum with everything ya want to know

http://moomba.com/msgboard/showthread.php?t=10260

plus there is a pic in my profie that shows the bep vsr dual battery set up

Surepower 1314 for sure!
I had an isolator and it worked well but was unable to ever get a complete charge. There is more than one volt loss through an isolator. One volt may not seem like much but when you only have a 13-14 volt capacity max and you loosing 1 through an isolator that adds up.
Perko switches work too but you always have to stop and think about which battery is on and being used etc.
The sure power only requires a simple jumper from your starting battery to the unit and a jumper from the unit to your aux battery.
It will always try to maintain a 13.2 volt charge on your starting battery.
If your starting battery drops below 13.2 it disconnects the batteries. When your alternator charges your starting battery beyond 13.2 the combiner connects your batteries together and keeps them together until your starting battery drops below setpoint, typically once the motor is turned off. Hence your starting battery will never go dead due to your stereo and your alternator will charge it automatically once started.
The best part is it can be had for less than $60.
http://surepower.com/pdf/separatorinterconnect.pdf
Let me know if you have any q's.
I dont work for, or sell surepower equip but I've have always had very good luck with the stuff.

Newty's is just like the blue sea and the bep marine vsr's
here is the install page
http://www.fourwheelcampers.com/batt...arator1315.pdf

the 1314 is single senseing the 1315 is dual sensing so you can home charge your aux battery with a charger maintainer first then it will maintain both after its fully charged

Thanks guys. I'm liking the Blue Sea setup. I'm leaning towards going with that. I like the fact I can combine batteries. I also like the "Off" switch.

The BlueSea is much more expensive than the SurePower, and the perko switch is totally unnessecary when you have the SurePower. The SurePower is a more advanced unit and actually costs less, about $65 after wakeworld discount through brettyates/polarbill. Surepower automatically combines or seperates batteries based upon power consumption, state of battery, which one needs charge, etc.

Are you going to upgrade alt too? Check dbalternator.com for nice american made alt for $80.

So one thing, kind of off on a tangent here, but it has to do with dual batteries and switches. I have just a Perko switch for my batteries. Settings are 1; both; 2; off. Now I was told that its good to turn it off when you are not using the boat because it is better for the battery. Well whenever I turn it off, my dang stereo loses all of its settings. Do I have it all wired wrong, or is that supposed to happen?