ideas on how to run accessories from a remote battery..?

so maybe not the most descriptive thread title, but ive been wanting to mount another vehicle battery in the spare tire compartment and wire all my lights (+sound stuff if that ever happens) to that so nothing is running off the car's main battery..

i need some ideas on how to do this..

if i run them all directly there, the battery will die fast...how can i keep it charged up but save my alternator some work..

but if i run the + of the main battery to the remote battery , wont that just drain the main one? and cause potentially more work for the alternator


not sure if any of that makes sense but hopefully some of you will get what im sayin :smt024

[anothernord]

Upgrade your alternator with one from a Tribeca or 3.0 Legacy. Part numbers are 23700AA500 , 23700AA510, 23700AA401.

Those are rated at 120 Amps, while the stockers are only 70A. That should power whatever you need without a second battery.

[Legacy89]

If that's not enough i hear good things about these alternators:
http://www.excessiveamperage.com/

[nomad666666]

http://www.ehow.com/how-does_5005295_ba ... -work.html (http://www.ehow.com/how-does_5005295_battery-isolator-work.html)

[ouch1011]

Quick look indicates that you need to update the connector to use a newer 3.0 or Tribeca alternator.

[Robbks]

We do this with our heavy off-road service vehicles where i work.

we wire the starter motor directly to the "Main" Starter battery, which has no other purpose except for starting the car. ALL other accessories and systems in the vehicle runs off the secondary battery.

the Main battery is only connected to the Accessory battery and charging system while the vehicle is running via an ignition sensed relay control.
this prevents the accessory battery from draining the Starter battery when the vehicle is not running

there is also a fail-safe circuit in place, in the event of the accessory battery being completely flat (and not allowing ignition power to operate the ECU and starter solenoid)
i.e you push a button which is powered by the main battery, which does allow current to flow to the accessory battery, this boosts the power in the accessory battery and allows the ECU to operate and initiate the starter and engine sensors. The Starter battery still has sufficient charge to start the vehicle.
then while the vehicle is running again, both batteries are charging