2nd Battery/ Audio Question
 

So i searched all the forums regarding audio/ battery installs and no one asked this one yet.

I have a smaller system ( one 4 channel 800w and one 2 channel 600w) and i dont want to kill my starter battery. On a tight budget why cant i just run an additional battery in paralell with a kill switch inbetween the positive cable? I would turn this on when i got to the lake, drive around and ride with the switch on, then turn it off when i stop for lunch. that shouldnt kill the starter battery... or am I wrong?
Also the second battery will be about 12' from the starter battery. Any problem with that?
Thanks for the help!

I don't see any problem with that. I actually have the same thing in my boat. It is just a kind of ghetto/cheap way of doing it. You have to remember to switch it every time or you run the risk of killing your starting battery. Not sure how much you are going to spend on a disconnect switch but a Sure Power 1314 does that automatically for a very reasonable price.

Just Get a Perko Battery switch
 

It would be just as easy to buy a 1-both-2 position Perko battery switch for $30, and with the same amount of wiring, you could switch between batteries each day...
ex. Run battery #1 all day, then battery #2 the next day.

If battery #1 dies, then just switch to #2 to get home!
If they are both weak, switch to the 'Both' position, this may have enough juice to get the engine started. The 'Both' position parallels the batteries, just as you previously described.

It gives you a spare battery that should be at 100% charge to get the motor running.

The alternator / charger would only charge the battery that was selected... unless you ran it on both for charging, then selected either battery for starting.

Here's a link to one for less than $30... I don't think you can get a decent battery disconnect for much less.

http://www.opentip.com/Sporting-Good...-p-663011.html

Thank You! Yeah I will prob get that Perko switch, and I am ok with the Cheaper way when it saves me $150 for gas money!

Make sure you get one that is "ignition protected" or "make-before-break" - this protects your alternator if the batteries are switched while engine is running.
Do not switch it off while running, however.

Here's the version with a key lock for $32.

http://www.opentip.com/Sporting-Good...-p-663012.html

Here's a link to a dual battery setup:

http://www.boat-project.com/tutorials/dualbatt1.htm


http://www.boat-project.com/tutorials/dualbatt2.gif

Matt, the Sure Power 1314 can be found for ~$60 or so. No reason to spend $150.

Matt,

Someone has an automatic battery isolator here, in the marketplace for $40.
http://www.wakeworld.com/classifield...g.php?view=318
A diagram of the hookup is one or two pages into the above tutorial at boat project.com

If I didn't already have one, I'd jump on it!

I still don't get the difference with a surepower or regular isolator that can be found on e-bay for 20$??

There are 3 main faults that I see with a regular isolator that are not present on a Surepower 1314. The isolator has a voltage drop of around 1 volt. This means that unless you wire around it or up the voltage a bunch on the alternator regulator your batteries aren't ever going to get a full charge from the alternator. Second the isolator doesn't give priority to the starting battery. It charges whatever battery is more depleted. Third there is no built in option to manually connect the 2 battery banks to aid in starting.