dual battery system suggestions?

Im looking to install a dual battery system in my van, but im not really sure how to do it. does anyone know the names of any books or websites that can show me how to do this?

It depends on what you are trying to do. Lots of diesel trucks use dual batteries hooked up in parallel for more cold cranking power.
The wiring it easy, one fat negative wire (try 0 gauge) goes to both negative terminals and one fat positive wire goes to both negative terminals.

However, if you wish to use one battery to run electical devices with the engine off, but still have enough power to start the engine, use a battery isolator. It will do just that, yet allow both batteries to charge when the engine is running. A place that specialises in RVs or pleasure boats can provide you with the parts and wiring diagrams.

thanks for the help.

two ways to set up batterys:

1. parallel - positive to positive, negitive to negitive, just like jump starting. the voltage of the batterys will be about equal, CCA will equal all batterys added together.
2. series - 1st positive to system, 1st negitive to 2nd positive, 2nd negitive to ground. voltage will equal all batterys added together, CCA will equal the weakest battery.

you want a parallel connection. first battery will remain at OEM placement. second battery can go almost anywhere you can fit it. if you place it inside the cab, you need to use a sealed mantence-free battery for safety reasons. some auto parts stores will sell a second battery kit or a battery isolater kit, you will want to buy one of these, you may also want search for a good radio/audio install website, they love power.

Sweet description of parallel and series, Sierra.