Your primary power source, when pitched up, for your caravan or motor-home is the same as as for your house, that is the grid. Your hookup takes the AC power into your caravan where it is used for all the usual kinds of things like television, heating and plugging things like your mini vacuum cleaner in to charge it up.
Mains power is the most important of your caravan power systems. The primary function of mains power is much the same as it it is at home. The AC supply usually operates at around 250/110 volts on a 50 hertz cycle depending on where you are in the world. As we carry more and more electrical stuff around with us the total load, especially during busy times, at campsites in increasing. This has resulted recently in power failures on some of the campsites that we visit. The sites will of course improve their supply to meet the demand but if there is anything that we can do to improve the way that we use resources such as electricity then perhaps we should should do it. In any event if your TV is a mains unit it will rely on the hookup to function, Likewise if you have heating or air conditioning on board this will also draw from the grid, as will anything that you plug into the mains outlet sockets in your caravan. Your water heater also draws power from the grid and most of these units are now very efficient.
One of the functions of the hookup is to charge your leisure battery via a dedicated charging unit. The battery supplies direct current, (DC), which when fully charged functions to operate things like interior lighting, the mover if you have one fitted, the water pump and the awning light. You will also more than likely find a twelve volt outlet, usually on the control panel behind your TV station. The manufactures often supply a plug/s for this outlet and you can easily make up a lead that will power 12volt equipment such as radio receivers, 12 volt television sets and other equipment made specifically for camping such as fans and portable fridges.
If you ever need to change your battery do make sure that you replace it using a leisure battery rather than a car battery. The leisure battery is specifically designed for what it says on the tin, that is leisure activities. Is is designed to discharge over a longer period and for a longer time than a car battery which is designed to discharge and recharge quickly in order to get your engine going.
While your leisure battery will discharge usefully over a deeper cycle and a longer period of time it is still of the highest importance to keep it fully charged whenever you can. This is easy while you are towing or while you are on site as the tow vehicle and the hookup both work to top it up efficiently. If you are away from a hookup or if your van is in storage then you may need to consider ways of regularly charging the battery in order that it will function properly when you need it. Some storage facilities allow you to connect to the grid and others may allow you to visit in order to plug it in once a month or so. They may also allow you to run a generator, although if your van is stored indoors be very careful to run the generator in the open air. Bring your lead indoors via a safe route where if will not be damaged or cause a trip hazard to others.
Suitable generators come in many shapes and sizes, however especially if you are intending to bring it with you on trips, ensure that you are getting the best weight/size to power output ratio that you can find. I use a 1kw petrol fueled unit, but I rarely find a use for it except to occasionally run it for a few hours to charge up the battery when the caravan is in storage. I’ve also used it to good effect for a ham radio operation where I needed to operate from the caravan and be independent of the mains. This is a Honda EU1000, which runs very quietly and is very portable weighing something slightly less than 30Lbs. It comes with an inverter built in which means that you can run both DC and mains equipment from it at the same time.
Another way of keeping your caravan battery topped up is to use solar panels. These can be fitted to your unit or they can be free-standing. If you choose to use free-standing units do make absolutely sure that they no not form a hazard of any kind.
You will generally need a few pieces of equipment as well as the panel itself. Firstly you will need a piece of cable to bring the current from the solar panel into your motor-home or caravan. Do consider using something like the high visibility and slightly tougher cable used in your hookup lead as this will make it easier to see. It will also stand up to slightly harsher treatment than many of the lighter wires that are often used. You will also need a control panel which will prevent your battery from being overcharged or from being discharged by reverse current drain.
Make sure that whoever sells you the solar panel kit fully understands their use with caravans and motor-homes and if you are in any doubt with regard to fitting them get in contact with your dealer or the manufacturer of your unit.
So far we have touched on AC power provided by the mains or by a stand-alone generator that you can carry with you. We have also looked at DC power available via the 12 volt socket in your caravan, directly from certain generators and from solar panels.
A very useful piece of equipment for RV owners, or indeed anybody who takes to the road in a vehicle of any kind is a combination power supply unit with a jump-start facility. Mine, shown to the left charging on-site, has two standard twelve volt outputs DC as well as a 5 volt DC USB output. It drives a compressor which I use regularly to keep the caravan tyres at the correct pressure. This means that I don’t have to shunt around filling stations trying the get my caravan close to the air pump. While many of them are very convenient it can often be difficult to get the trailer exactly where you want it. This is more to do with my driving ability I suspect than the layout of some filling station forecourts.
A useful feature on this, and many other portable units is the efficient work-light. It also has flashing amber lights that emulate the hazard lights of a vehicle, useful if you car power system fails or for giving advance warning of a road hazard.
What happens if you have a 12 volt source, for instance a solar panel and you want to, in the absence of any other source of AC, power your mains driven equipment? The answer is a simple-to-operate little device called an inverter. This simply connects with your 12 volt DC (Direct Current) source and converts it to AC (Alternating Current) at a value determined by your inverter of choice. For instance in the US you will use a 110volt device while in Europe a 25o volt one will be used. You need to decide which jobs you need the inverter to do and then choose the size accordingly. They range from simple cigarette lighter fittings at about 80watts to larger 1000watt or higher units for tougher jobs. Do be aware that your DC power is limited and that the inverter itself uses some of your precious DC so this technique may not be suitable for long term or very robust use.
Mains Supply Unit
If you you are using a tent or a unit which does not have a built in mains supply system, then a site mains supply unit might be just the ticket for you. The standard caravan mains system has an earth leakage circuit break system built into it so if a problem occurs a trip switch will activate protecting the system and any appliance that you have connected to it.
There may be a temptation to connect to the mains on the campsite using a simple extension lead. Resist that temptation! It will most likely end in tears! Instead look for, and find a proper campsite main supply unit. This consists of a standard connection to the site power outlet, a high visibility outdoor lead and a socket board with earth leakage circuit breakers built in. You can choose a socket board to suit your requirements but usually three or four outlets are adequate for your needs.
Do be careful with these things. Even though you have bought the proper kit do ensure that you mount it clear of obstacles where it won’t form a trip hazard and where it is away from the danger of getting wet, being driven over or otherwise maltreated. I have seen them left lying in the open in the rain which is not a good idea. Keep it indoors and do consider purchasing a unit which has a mounting system either as standard or as an option.
If you would like me to chase down any information about these products just let me know and I’ll put the information up here for everybody to use.