Know Your Electrical Systems
What's the difference between a converter and an inverter? A converter will take a 120V power supply and convert it down to a 12V power supply, allowing you to power all of your 12V appliances and lighting while simultaneously charging (and even maintaining) your battery. An inverter will take your 12V power supply (a single battery, or a battery bank) and invert it to 120V. Inverting from 12V to 120V is a much more demanding process, so don't expect too much from a single battery when powering 120V appliances.
How do I know what size power supply I need? When it comes to recreational camping, there is no one-size-fits-all in the area of electrical. The most common size power inlet is 30 amp, delivering up to 3,600 watts of 120V power. Most large RV's and Fifth Wheel campers will have a 50 amp service, delivering 12,000 watts of 120V (50 amp has two 120V "hot" wires, where 30 amp has one). You can estimate this using the "Amps x Volts = Watts" formula. This is also very useful when deciding what appliances you can operate at the same time under your current power load!