I have a light bar that pulls close to 22 amps how long can I have it on and my jeep off without hurting my battery?
Calculate it yourself:
If you have a full 66Ah battery, it will be drained within 66Ah/22A=3h.
- A battery degrades over time, after a few years, the capacity isn't 66Ah any more.
- An almost empty battery isn't capable to deliver the same max. current as a full battery. If it's almost empty, you could have problems staring your motor. This is even more important in cold conditions.
- It takes quite a while for the car to charge a fully discharged battery. May be an hour or two?
- Deeply discharging a battery damages it. A 12V is considered empty when it gives about 11.5V. But you can still draw current, which will then damage the battery and reduce it's full capacity.
I'd say depending on the age and condition of the battery, when math says 3h, don't use it for more than 2h, better less. You never REALLY know how much capacity your battery has, and how full it is.
BTW: 22A*12V=264W. Are you lighting a sports field? Maybe, LEDs are an alternative?