Just got my 50" led bar in and also have a sub and amp coming in a few days. The sub will be powered constantly and the led bar will be switch fed and not used nearly as much. Think a 2nd battery is in order or do you think I could get away with powering everything off of one?

 

No.

I run two amps off my battery just fine. Your LED light bar will draw very little juice, and at this point a second battery wouldn't do you much good.

 

I would do a bigger alternator before I would add another battery. Mine can barely keep the battery charged when the bass is pumping with the lights on at night.

 

You are probably fine with one battery until you add more power-hungry toys.

When/if its time for more power, a second battery gives you more power when parked or when you need more power than your alternator can deliver while running (mainly when winching). A bigger alternator provides more power while the Jeep is running. Which one works best depends on how you use the Jeep.

 

A single deep cycle battery should do the job