Leisure Batteries

If however, you are not sure what battery you need, please read the following selection guide...

A car battery is designed to give out a large amount of power in a short space of time (to start the car) and then being quickly recharged. In contrast, a leisure battery is designed to store power and release it gradually, over a much longer period of time. You could probably use a car battery in your caravan or motorhome, but it’s unlikely to work very well in the long term.

Battery power is measured in amp hours (Ah). The higher this number is the better, as this gives you an idea as to how long a full charge will last.

Calculating Battery Size

This is actually easier than it sounds and simply consists of calculating how much electricity you will use before you need to recharge. Let's take a look at the typical electricity consumption in a motor-home or caravan:
•    3x lights @ 8 watts each run for 5 hours = 120 watt-hours
•    1x striplight @ 10 watts run for 6 hours = 60 watt-hours
•    1x water-pump @ 50 watts run for 15 mins = 13 watt-hours
•    1x colour TV @ 50 watts run for 4 hours = 200 watt-hours

If you now add up the total watt-hours used i.e. 120 + 60 + 13 + 200 = 393 watt-hours

To work out the total number of amp hours you divide by the voltage (12v), so 393 watt-hours /12 volts = 33 amp hours.

How Long Will a Battery Last in Practice

If you followed this consumption pattern and ran a 110 amp hour battery to total discharge it would last just under two days. However, in reality, you would not get this performance because of:

•    If you run a leisure battery to total discharge it would not be as effective.
•    Amp hour ratings given to batteries are based on new batteries and in ideal conditions

And to allow for the ageing process you should assume that it will ultimately not charge above 80%, thus meaning that if you want to get the maximum life and satisfaction from the leisure battery in your motorhome you should assume that just 30% of its capacity is available for your use!

So, continuing on from the example above, if 33 amp-hours is 30% of the battery capacity, then 100% of the battery must be 33 x 100/30 = 110.

You would, therefore, need a 110 amp-hour leisure battery in your motorhome/caravan for maximum comfort and battery life.

In practice, of course, the size of battery you can fit may also be determined by certain physical constraints such as the amount of space available to fit it in, so you should also consider the physical dimensions of the battery when making your choice.

If your motorhome needs a leisure battery, you'll find a suitable one here. Similarly, there are caravan leisure batteries.

They are interchangeable, so please make your choice from the range below: