How do you install another battery?  I am thinking about running possibly 3 batteries and wanna know how you install them and what you need to do it?  I am going to be running a mild stereo system and want to make sure that it wont drain my main battery.  thanks

I'm going to give you the "golden goose fix", but can be done much less expensively, so bare with me...

First a question, why the hell do you need three batteries?   

You will need to think it through.

Figure out what you are trying to achieve, you always want a charged battery, so I highly recommend a battery isolator (not two), a battery isolator is a fancy name for a set of diodes. When you install the batteries use a battery switch, Marine preffered, but not required (may say the words "Vapor Proof"). Battery one (1) I always use for a starting battery (to each his own) this battery will be connected to battery switch terminal #1 and have one line from the isolator to that same terminal (#1), the next battery will be #2 and should be connected to the #2 terminal with the other side of the Isolator going to #2 of the switch, the middle terminal goes directly to the alternator charge wire..

Now, if you really want the third battery, the best way to do it is to use a constant duty relay on a switch at the dash and use it for the stereo only, the relay will charge the battery only when the switch is "on" and the engine is running, run a wire from battery #2 to the relay and from the other pole of the relay to the positive post of the #3 battery.

Then power up the relay using the ignition circuit to a dash mounted switch to the coil of the relay, this allows you to isolate two batteries from eachother (does not matter what position the switch is in to charge both batteries) and if you run the switch in #1, there will always be a "spare", charged battery, the third gets charged from the engine when the under way and is isolated from the engine when you want noise free tunes while idling alond (hence the switch)..

And there ya go!  You can link two batteries together, but I don't care for that method...

GT

I'm going to give you the "golden goose fix", but can be done much less expensively, so bare with me...

First a question, why the hell do you need three batteries?   

You will need to think it through.

Figure out what you are trying to achieve, you always want a charged battery, so I highly recommend a battery isolator (not two), a battery isolator is a fancy name for a set of diodes. When you install the batteries use a battery switch, Marine preffered, but not required (may say the words "Vapor Proof"). Battery one (1) I always use for a starting battery (to each his own) this battery will be connected to battery switch terminal #1 and have one line from the isolator to that same terminal (#1), the next battery will be #2 and should be connected to the #2 terminal with the other side of the Isolator going to #2 of the switch, the middle terminal goes directly to the alternator charge wire..
  Whoa I think I need a smoke     Good tutorial !
Now, if you really want the third battery, the best way to do it is to use a constant duty relay on a switch at the dash and use it for the stereo only, the relay will charge the battery only when the switch is "on" and the engine is running, run a wire from battery #2 to the relay and from the other pole of the relay to the positive post of the #3 battery.

Then power up the relay using the ignition circuit to a dash mounted switch to the coil of the relay, this allows you to isolate two batteries from eachother (does not matter what position the switch is in to charge both batteries) and if you run the switch in #1, there will always be a "spare", charged battery, the third gets charged from the engine when the under way and is isolated from the engine when you want noise free tunes while idling alond (hence the switch)..

And there ya go!  You can link two batteries together, but I don't care for that method...

GT

Whoa Glenn ,I think I need a smoke  Good tutorial !

Whoa Glenn ,I think I need a smoke  Good tutorial !

Thanks Tom! 

GT

okay sweet.  thanks for the info guys.  ill be installing another battery on thurs or friday along with the system.

Dont forget the battery switcher