ok so i am a newb to the whole dual battery world I know on my tj i would have to rev up during winching or it would kill the battery very quick now with the new jk to avoid that can I just buy a dual battery tray and pop to batteries in and it will be like 1 huge battery or do they run separately like one to crank and one just for winch and accessories? what am i in for on this? future plans are a winch dual arb compressor maybe some lights, i never welded do i dont think I will need an on board welder so with those basic add ons will I need a dual battery?
You are describing the need for a dual battery system with an isolator (to separate them). If you run the batteries in parallel and connect the winch to one of them, you will most likely draw current from both, and deplete both. If you use an isolator, and again connect the winch to one battery, you will deplete only that one battery ... which is hopefully not the same battery you use to power your vehicle's electrical system.
The JK alternator, depending on year, puts out about 160A. The stock TJ alternator (according to a Google search) puts out ~120A. That 40 amp delta is a huge difference! Even at 160A, however, you can deplete your battery during winching. Two ways to mitigate--but not entirely prevent--that:
1. Rev the engine manually (or electronically if you're lucky enough to have a button, etc., to do this for you) like you have before.
2. Buy a high output alternator that puts out more amps at lower RPMs.
Buying a marine grade or deep cycle battery is also a good idea if you think you're going to deplete it.
Below is an example of a wiring diagram for a dual battery system (I found this online; not my own drawing). Ignore the Amperage ratings on the accessory fuses; you would need something much larger for a winch. My guess is 200A or so.
The "Intelligent Solenoid" depicted is something similar to a Cole Hersee 48530 isolator. They are included in most turn-key systems. Hope this helps.
-Dawn (with help from Chris LOL).