Modern Caravans, Campers, and Motorhomes can be powered by both 240v when at a powered site and by batteries (usually 12v or 24v) when mains power is not available.
Many modern Caravans are a combination of both 240v and DC systems so that you have all devices powered regardless of the situation. (All 240-volt electrical work is covered by Australian regulations and can only be worked on by a qualified and certified electrician.)
With modern lighting technology e.g. LEDs and a large range of 12/24 volt appliances available, 240v is not always required to provide all the comforts.
12 Volt Systems
Some units have a simple solution that, when mains power is available, a 240v battery charger charges the batteries which powers all the lights, fridge, entertainment systems, etc within the unit. In this situation, all devices are DC powered and cannot supply 240volt power. With this system, high powered appliances such as Air Conditioning, hairdryers, coffee machines will not be available unless a separate 240v circuit has been included, which may be a single internal power point.
Unlike 240-volt systems, which can only be worked on by a qualified electrician, 12-volt systems can be worked on by non-electricians. If you are working on a 12-volt system, make sure to use electrical cable of the right size. Make sure to check the diameter of the conductor (excluding the insulation around the cable) to make sure it is the right size for your 12-volt system.
With newer technology, including Inverter Chargers, Deep Cycle Batteries, and Mobile Solar Panels. Caravans and campers will use a combination of DC Lighting, fridges, water pumps, and entertainment systems as 12v and higher power appliances such as Microwaves, Air Conditioning and coffee machines, etc from the 240 power.
With these systems, when mains power is available, the charger part of the inverter charger charges the batteries and provides 240v power for the appliances that require this. When Mains power is not available, the Inverter part of the inverter charger converts the DC power from the batteries to provide 240v. The amount of time this can occur and the available 240v power is dependant on the size and capacity of the batteries and the inverter.
240v Only Systems
This is far more common in older caravans (and seldom in modern vans) that were designed and built before the introduction of inverters whereby the only source of power was from a 240 mains supply which powered all the appliances.
Inverters and Inverter Chargers
An inverter converts DC Power to AC Power and range in size from 150watt modified sine wave units that will plug into your Ciga Socket to charge a Laptop etc up to many kilowatts.
Inverter Charger will work both ways and, when mains power is connected, will charge your battery bank and when off-grid, will provide AC power to run your appliances.
When using the AC power from your inverter, you will need to consider the total power required, and the length of time the power is needed so as to be able to have a battery bank that can provide the required power.
There are 2 common types of battery in use in Caravans. These are Lead Acid Class batteries including GEL CELL, AGM, and Sealed Lead Acid and now becoming more popular is Lithium (Lithium Iron Phosphate LiFePO4).
With the price of Lithium batteries decreasing and the quality and reliability increasing (Now with 5-year Warranty and expected life of 5000 cycles at 50% depth of discharge) the initial purchase price is more than made up for in lifecycle and weight saving.
The Lead-Acid type battery should only be discharged to 50% capacity where Lithium can go beyond 80% discharge.
When Choosing batteries, you will need to consider the Power Rating i.e. AMP Hours how long can I flow current for and Flow Rate – how much current can the battery produce. This is critical when deciding e.g. a 110AH Lithium battery will typically flow 100 amps for 1 hour whereas a Lead Acid battery may flow 100 amps but only for 30 minutes until 50% discharge is reached. Always check the manufacturers specifications for the actual flow rate.
Flow Rate is important as a 100 amp flow at 12volts will provide 1200 watts at 240v. Note that a 1000 watt microwave oven may require up to 1700 watts of power to run. Therefore it is important to understand how much power you really need.
Solar for your Caravan
There are essentially 3 types of Solar Power available for Caravan / Camper use.
Similar to the panels we see on many roofs but designed for lower voltage output for the Caravan / Camper situation. These are also the type of panel in Portable folding panels.
These have solar cells incorporated into a flexible substrate and designed to be adhered to the roof of the van or vehicle surface. The advantage is being very low profile ( only a few mm thick) and has less drag than a rigid panel.
The disadvantage of both fixed panels is that you need to park in the sun for them to work.
The beauty of the solar blanket is that you can park in the shade and have the solar blanket in the sun. Also, (depending on capacity) fold up to a compact package for transport and they are portable and provide power where you are if away from the van.
So, as you can see, there are several things to consider when buying or upgrading your caravan. Call us today to speak with our caravan and outdoor living expert.