Making, storing, and using power wisely is important for happy vandwelling. Power issues can seem overwhelming and confusing; this article intends to lay out the basics.

Before you spend money on making/storing power in your vehicle, be sure to leverage other sources:

• plugs at your work, church, or anywhere else you visit regularly
• plugs at cafes and restaurants – ask for a table near an outlet
• look for outlets at bus stops, park pavilions, etc.

It may be useful to carry a gym bag with a power strip, extension cord, and any items that need to be charged. The power strips allows you to charge many things at once, and the extension cord helps you reach faraway outlets or outlets in inconvenient places (on a wall, behind furniture).

There are two generally-separate electrical systems in your vehicle¹⁾:

• House power (coach power, leisure power) is the (usually 12v) electrical system in the living area. It runs fans, lights, etc. It's what we are discussing here.
• chassis power is the electrical system in the vehicle itself. Starter, alternator, headlights, etc. The two are usually separate systems, except when actively charging from the alternator.²⁾

Only you will know that, because only you will know what kinds of electrical loads you need (or want) to run. Unlike a wall socket in a house where you can run pretty much anything you want, using power you make off-grid is a series of choices and compromises. Some things are easy to run off-grid; some things are harder and require more infrastructure, planning, and money. Some things are impractical in campervans. Car-dwelling presents additional power challenges due to limited space and charging methods.

There is no way around it: you must come to grips with how much power you need each day.

1. be honest about what you want/need to run and how long you plan to run them
2. do the math, or use a calculator to do it for you

Here are some very general ideas to get you thinking:

• Trivial to run off the cigarette lighter port while driving
  • phone and tablet charging - can also be charged from a USB battery pack.
  • laptop charging
  • ⇐100w loads from small inverters. Note that most small, inexpensive inverters are modified sine wave and not appropriate for all loads.
• Easy to run off a portable power pack³⁾
  • fan
  • CPAP - especially with humidification turned off
• Average loads - small ($) house power system: Example: 200w of solar and 100Ah of battery.
  • 12v compressor fridges – they use little power and run intermittently
  • laptop charging/use during the day
  • roof vent
  • swamp coolers (due to high power fan motors)
  • gaming laptops run off solar during the day
  • 120v refrigerators off inverter
  • charging e-bikes, etc during the day
• Harder and more expensive to run - substantial ($$$) house power system - 400w+ of solar, 200Ah+ of battery
  • charging/ussing laptops at night
  • gaming consoles|laptops|PCs
  • charging e-bikes, etc at night
  • Small microwaves when used for <3 minutes per day
    • Power draw is high, but duration is short. Needs a beefy inverter.
• Difficult and very expensive to run - Massive ($$$$$) house power system - 600w+ of solar, 400ah of lithium battery, alternator charging.
  • Cooking with electricity, which is why we use propane
    • This includes things like insta-pots, electric stovetops, toaster ovens, larger microwaves, etc
  • air conditioning, which is why we go where it is cooler
  • electric coffee makers, which is why we use propane⁴⁾
• Completely Impossible unless you're on shore power
  • Heating the van. Tens of thousands of dollars in lithium batteries will barely last a day of running an electric heater. Which is why we use propane or diesel.

Note: devices that have "wall wart adapters" typically will not necessarily require an inverter.

Most campervans use solar combined with another charging source, usually the van's alternator. This combination can be both cheap and highly effective⁵⁾

Alternator & solar charging enhance each other when used together. Adding alternator charging to solar can significantly reduce the amount of solar required to meet your needs.

Note: So-called solar generators do not generate power: they are battery banks, usually AGM or lithium. See below.

• People who can camp in driveways can cheaply run shore power to the van with an extension cord.
• people who weekend camp can charge the batteries from shore power on their return, augmenting with alternator, solar, or generator if needed
• people who drive hours each day (delivery, trucking, etc) may be fine with DC-DC charging alone. This also applies to lithium chemistry batteries
• people who spend long periods off-grid will probably want a robust solar install
• people who want to run big loads off-grid can do it cheapest with a generator.

Power production tends to be heaviest during the day while power use tends to be heaviest overnight. This means power needs to be stored when power is abundant so it can be used later. The most common storage for power is in a deep cycle battery bank.

The battery bank is sized to meet your daily power needs and as well as any extra margin you might like.

Using power is the simplest part. It's so simple the newbie may find themselves overdrawing from the available power. A low voltage disconnect (LVD) is one way to keep from overdischarging the bank.