If you wish to run 240V appliances such as a
240V TV or a laptop computer in your RV from a 12V system
you will need to install an inverter.
An inverter is an electrical device that converts 12V Direct
Current (DC) from the batteries to 240V Alternating Current
(AC). Invertors also draw their power from a 12V deep cycle
battery or battery bank (several batteries wired in
As inverters produce 240V always exercise
as it is as deadly
as mains power.
When investigating inverters you will come
across the terms square wave, modified square or sine wave
and pure sine wave. The most popular inverters, even though
they are a bit more expensive, are pure sine
as they deliver the most constant output and run sensitive
appliances such as laptop or notebook computers. The
cheaper inverters are modified sine – don’t be fooled into
purchasing anything but a pure sine if you wish to run
switch mode power supplies such as used for laptops or
inverters come in a range of models and sizes that vary in watts.
If you just require power for say two lights, a radio and a small
laptop computer then a 500W inverter connected to a 12V power socket
may suffice but if you wish to use a larger laptop computer, DVD or
TV and mobile telephone charger or a bread maker then a larger
inverter would be necessary. If you want the inverter connected
into fixed wiring this work must be done by a licensed electrician.
Some electrical appliances have a ‘start up surge’ or
‘peak load’ when turned on which is much higher than their
continuous draw or ‘continuous load’ so the size/capacity of the
inverter will need to cope with this. Another example is if you
wish to use tools such as an electric drill then the size/capacity
of the inverter would need to cope with the drill under load.
Adequate power stored in the RV battery bank would also be needed.
Depending on the way the wiring has been done you may
have to turn off the RV battery charger when using the inverter.
off-road caravans are now having the 240V wiring specifically
installed in their RV to be able to isolate the battery charger and
the air conditioner when the inverter is on, but still run those
appliances from the generator at the same time if they wished to do
electrical work must be carried out by a licensed electrician and
you should let the electrician know there is an inverter installed.
The Owner’s Manual for the Xantrex 1800W inverter
states in part - ‘disconnect the DC power
(and AC power if applicable on hardwire versions) from the Sine Wave
Inverter before attempting any maintenance or cleaning or working on
any equipment and circuits connected to the Sine Wave Inverter.
Turning off controls will not reduce the risk’.
These large Xantrex 1800W inverters are designed to
be used with deep-cycle lead acid batteries and Xantrex recommend a
minimum battery size of 200 Ah for moderate loads (less than 1000W)
and greater than 400 Ah for heavy loads. The Xantrex owner’s manual
also provides information concerning cables and adequate cable
Some brand names/suppliers for inverters are Xantrex
Technology Inc, Victron Energy Shop, Smartpower Inverters, Vector
Inverters and Sinergex Inverters.
Inverters can also be purchased from Bainbridge
Technologies, Dick Smith Electronics, Jaycar Electronics, Springers
Low Voltage Specialists, Rainbow Power Company Ltd, Solar Xpress,
The 12V Shop as well as RV accessory outlets.
you don’t want to use an inverter, then 12V appliances
are available but you may find some of these expensive as well as
draw too much current. Further, the caravan wiring may be
inadequate for the amount of current these appliances draw.
are generators that have an additional smaller 12V DC output for
running 12V appliances direct.
12V appliances can be sourced from specialty stores,
some caravan and camping outlets, Camec, Boating Camping & Fishing
(BCF) stores as well as marine stores.
Essentially, you will still need some mains
electrical backup, diesel fuel or LPG gas to run any hot water
system or for cooking.