[Car Camping] Improve car camping power efficiency? 

Using a 2.5 kilowatt-hour lithium iron phosphate battery is not exceeding the budget, and provides sufficient power capacity.
I can also do high-power-consuming activities such as cooking and air conditioning, and take advantage of the characteristics of DC appliances by using multiple devices simultaneously.
timecode:
0:00 Intro
0:41 Off-grid vs Mains
2:47 Efficent electricity use
5:13 Build a DC power system
8:31 24Volt vs 12Volt
10:36 Running the AC, boiling water, cooking rice, and frying meat simultaneously