articles and blog
Where does your power come from?
Category: Facilities in your home-on-wheels. Published: 23 Jun 2009
Many appliances and facilities in a campervan, motorhome, caravan or recreation vehicle require power of some sort. Power needs vary depending on the number and type of appliances being used and also on where you intend staying -- requirements in a caravan park vary from those required when bush-camping or free-camping. I am in no way an expert on this subject -- the notes below are from my experiences from living in a van.
Some of the items to be considered when deciding on your power needs are:
- Cook-top, oven and grill.
- Microwave oven.
- Water heater.
- Air conditioning/heating.
- Radio/CD/DVD/MP3 player.
- Washing machine and clothes dryer.
Propane gas is generally used for powering stoves in campervans, motorhomes, caravans and recreation vehicles. It may also be used for running a fridge and/or water heater. Gas is generally supplied in 5 or 9 kg bottles, which can be refilled or exchanged at various caravan parks, service stations or camping supply stores. From what I can gather there is no real reliable method of estimating how much gas is left in a bottle so I, as many others do, carry two bottles. As soon as one is empty I swap over to the other then get the empty one refilled or exchanged. In my first van I only had one bottle and it would generally run out when I was in the middle of nowhere. I tried using a magnetic strip that is supposed to let you know how much gas is in the bottle when you pour boiling water over it, but I found that lifting the bottle and guessing its weight was far more accurate.
Mains power is provided at a powered site in a caravan park. This varies between countries, but in Australia this is 240-volt AC current and requires a 15-amp lead. The standard domestic power outlet is 10-amp so is not suitable.
Mains power is used to run a number of appliances, including to recharge batteries. Items such as air conditioners, microwaves, space heaters and water heaters generally require mains power.
House batteries can be used to power a number of appliances in a campervan, motorhome, caravan or recreation vehicle. They are particularly used for lights but can also be used for an increasing number of appliances, such as the TV, CD/DVD player, water pump, fridge, electronic ignition on cook-tops, slide-on jacks and slide-out motors. Appliances such as air conditioners, space heaters and water heaters cannot be powered by battery, and microwave use is limited, as their load is too heavy and would run down the batteries too quickly.
House batteries usually generate either 12- or 24-volt DC power, which can be converted to AC power by an inverter for those appliances that require it. They are generally deep cycle batteries, which are different from car or truck starter batteries. Deep cycle batteries are required to provide a smaller load for a long time, while starter batteries provide a high charge for a short amount of time. Deep cycle batteries should not be drained below about 50% at any time. Batteries are rated in amp-hours and the number and size required will depend on the appliances to be run from them, and the ability to recharge.
Batteries can be charged by mains power, the vehicle's engine, a generator or via solar panels.
An inverter converts 12-volt DC power to 240-volt AC power that's required to run a variety of appliances. There are two types of inverters: pure sine wave and modified sine wave. Pure sine wave are more expensive but are required for the more sensitive appliances. Both types of inverters are available in various sizes, rated by their output in watts. The size and type to be installed depend on the appliances to be run from it.
Solar power is becoming increasingly popular with campervans, motorhomes, caravans and recreation vehicles. A number of solar panels are installed on the roof and are used to charge the house batteries. Panels come a range of sizes and the number and size installed vary according to the number and type of appliances being run from the batteries.
Generators are used to provide AC power or to recharge house batteries, are usually powered by diesel or petrol and are rated by their output in watts. Generators are generally used when free-camping, although they are usually banned in national parks due to the amount of noise they generate, which then generally tends to generate arguments.
I can't comment very much on generators because I've never used one. The solar panels generate enough power for my needs while I'm bush-camping, but it means I can't use my microwave or air conditioner, so in the hot weather I'm restricted to staying on a powered site in a caravan park.
There are a variety of ways to set up vans and appliances. In my first van, most appliances ran on 240-volt power, so these were powered directly when I was hooked up to mains power or were plugged into the inverter when I was bush-camping. Lights were on two circuits meaning they had different switches and could be run from either 240-volt or 12-volt. Most appliances in my current van run off 12-volts, so when I'm hooked up to mains power this charges the battery which then powers the lights, TV, CD player etc. The air conditioner and microwave only work when I'm connected to mains power (I didn't have either of these in my first van). In both vans the fridge ran from either -- if I was connected to mains power it used this, if not it automatically switched to battery power.