This depends on the length of the fence, amount of vegetation likely to grow
on the fence line, type of animal to be contained or excluded, the fence line
being proposed, and the power source for the energiser.
Where possible, always use a mains-powered energiser sited inside a building.
Running costs are low (unlikely to exceed £20.00pa) but best of all, no batteries
to go flat and less likely to be damaged by animals.
Dry Battery Energisers – 6v and 9v
Dry battery powered energisers are ideal for temporary fencing, particularly
strip grazing and short fences. Use an energiser with an internal battery such as
These are lightweight and easy to relocate, require no maintenance and generally
the batteries last 1 – 6 months before replacements are needed. These batteries are
Wet Battery Energisers – 12v
If the fence is moved infrequently or is semi-permanent and no mains power
is available, then select a 12v energiser together with a 12v, 75 Ampere Hour (Ah)
leisure battery (Part No. 22-107).
The higher the A/h. the longer the period between recharges. Generally these energisers
are more powerful than dry battery versions and can operate longer fences.
Solar Charged Battery Energisers
Solar charged battery powered energisers are ideal for temporary and semi-permanent
fencing, particularly strip grazing and short fences. These are lightweight and
easy to relocate and require no maintenance.
Volts – This is the pressure behind the
flow of electricity to push the energy along the conductive fence wire (similar
to air pressure). Most energisers produce up to 10,000 volts and about 3,000 volts
minimum (measured by a volt meter, Part No. 14-171), is needed at the end of the fence to
Ohms – This is the measure of resistance, rather
like friction of water running along a hosepipe. Small diameter fence conductors,
such as those in poly wires and tape have high resistance and are used for short
fences. Large diameter wire such as 2.5mm high tensile have low resistance and can
be many kms long. Vegetation growth on a fence line acts like a leak in a water
pipe and "shorts" the fence to earth thus reducing its effectiveness.
Joules – This is the amount of energy available
to be pushed down the conductor by the energiser and is the measure of shock felt
by the animal. This is rather like cubic capacity or volume. Higher joules mean
Amperage – The measurement of electric current
and what you feel when you get shocked. The higher the amperage the more intense
shock the animal will feel.