No hook up? - No problem!

If you’re new to motorhoming, you may not realise that space heating, water heating and refrigeration are nearly all designed to be run on gas as well as mains electricity. Most motorhome electrical equipment runs off 12 volts and so can be powered from the on board battery when there is no mains hook up. Making that battery last is all about using its power as efficiently and economically as possible and, if necessary, finding additional sources of 12 volt power.

Rallying for  2-3 days with a good, charged battery, should be no problem, even if a 12 volt TV is on for 1-2 hours per night. Beyond this, additional power sources may be needed.

It’s important to understand how much power is consumed by the various 12 volt devices.

From the table below you will see some use a lot more power than others.

Power is measured in watts - the more the power the greater the watts.


Power consumed (watts) 12 watts = 1 amp

17” LCD colour TV

35 - 50

15 “ LCD colour TV

25 - 40

19" LED colour TV


Satellite receiver / Freeview box


TV aerial booster


Halogen down lighter

10 or  20 (depends on bulb wattage)

Fan for blown air heating

10 – 50 (depends on speed setting)

Fluorescent strip light

6 - 7

LED strip light

2 - 3

LED spotlight

2 – 3


Fluorescent lights use less power than halogen lights and LED lights are more efficient again. Very recent advances in technology mean that LED lights are now available in warm colours and only use about 15% of the power taken by an equivalent halogen light. Some are even available as direct replacements for the spotlights found in more recent motorhomes.

Using power efficiently is the first step to managing without a mains hook up. After that it’s time to consider how you can supplement the power provided by the motohome battery. The simplest and most cost effective way of getting additional power is to buy a second battery.

Should you wish to do so, it is possible to connect two batteries. However there should be a suitable fuse local to each battery and (ideally) the batteries should be identical. This arrangement can work well when used in conjunction with solar panels. Installation should be by a competent electrician or your dealer. A second lead can be purchased from Sargent Electrical.

Another way of providing additional power is by using one or more solar panels. Modern panels give useful output in cloudy conditions and can be used in the winter months. To be effective though you need a panel with a rating of at least 80 watts. A good quality crystalline panel will cost under £200 from Ebay.  Make sure that any panel you buy comes with a charge controller. This will prevent it from overcharging the leisure battery. The most efficient type is an MPPT controller, which will cost around £100 for one of reliable quality.

An 80 watt panel can be enough to keep you running indefinitely during the summer months*. In spring and autumn such a panel can greatly reduce the net drain on the battery, thereby making it last much longer before becoming flat. (*Depending on usage).

Of course you can go the whole hog and have 2 or even 3 large panels installed on the roof of your Motorhome. These can then be permanently wired via a suitable controller to the on-board 12 volt system or direct to the batteries. This is a job best left to professionals.


     80watt Solar Panel              Solar Panel Regulator          Free standing Solar Panel


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