How to choose the Right Fence Charger

Electric fencing is great for both temporary, moveable fencing or something more permanent.  If you are thinking about erecting some electric fencing you may be deciding which fence charger you need – let’s take a look.

The fence charger can also be referred to as an energizer or a fencer.  These units provide the electricity source providing the current flowing through the fence wire, without it you just have fencing.  They have a number of differences, but the main difference is the current which is output by each unit, and the origin of the power source.

Energizer size varies, and you need to decide what size energizer you need to meet your particular requirements.  There are four factors that will affect this:

  1. The number of strands you are running for your fencing.
  2. The length of the fencing you wish to run current through.
  3. The Power source that you choose – you can use AC, DC or Solar power.
  4. The animal that you are trying to fence in, or out.


You may see three terms that you need to understand;

  • Continuous output. This means that rather than a pulsing charge through the fencing there is a constant charge.  These energizers are recommended for use on smaller paddocks and dairy stalls.
  • Solid State. These energizers deliver a medium amp shock and the pulses are of medium duration.  These are recommended for short-haired livestock, smaller animals and specifically where you have light weed conditions.
  • Low Impedance. With this energizer there is less resistance (impedance) in the charger itself, so more of the power is pushed through to the fencing.  These are the latest, and best technology for heavily weed infested land.

The Three Types of Fence Energizers

As we have already mentioned there are three types of fence energizers available:

  • AC (Mains – Plugin)
  • DC (Battery)
  • Solar

You will be using the type of charger which suits the power source you have chosen for your fencing.  Each type has recommended situations which differ, so selecting the correct power source, and therefore the right energizer, for your particular situation is fundamental to keeping stock in – or out.

Things to consider

  • The location of your power source.
  • The necessary energy output for the unit (measured in joules).
  • The animal you are working with.
  • The length of fencing being powered.
  • The vegetation in the immediate area.

For convenience, greater output and reliability of current AC powered models cannot be beaten.  This also gives you great flexibility over the length of fencing you can power.

Let’s take an in-depth look at the three options:

AC Power fence energizers are fabulous – you need a reliable source of 110-volt electrical power.  To make generalizations, AC chargers provide the best output, don’t fail, maintain great distances, and are consistent.  They are currently the most popular energizers in use for permanent electrical fencing.  The range available can give you distances of up to 200 miles.

DC (Battery Operated) fence energizers are a brilliant solution for areas where you have no mains access as they are mobile and easily moved.  They can be powered by a variety of batters – 12 volts, 6 or 4 volts, or D Cell.  To use a broad brush explanation the larger the battery the longer it will last, the more volts it can deliver.

The battery comes separately to the charger – if you get a rechargeable battery you can recharge it, otherwise, you would need to replace it.

The replacement interval of the battery will depend on how often the charge running through the fence is grounded.  So if you have weeds or shrubs touching the fence, or animals who are not used to fencing and haven’t learned to stay away so they touch it, then it will drain faster.

The recommendation would be a 12 or 6-volt rechargeable deep-cycle battery.

The obvious flaw with a battery drove fence is that you must check them and recharge them frequently using a voltage meter – if the battery drains then there goes your electric fencing, and it becomes just fencing.

  • Solar Powered energizer is great for remote locations which need a continues output. They are lightweight and easy to move about for temporary fencing which means that for strip grazing or rotational grazing they are a good go-to.   These systems also have an integral battery to store the power and deliver when it’s needed – in effect the solar doesn’t power the fence, it recharges the battery and the battery powers the fence.
  • The battery should be good for around 3 years, so they are a fairly useful investment. The recommendation is to have a back-up gel-cell solar battery alongside a trickle charger so that you know you won’t ever get a power outage.

Choosing the Right Energizer for your Electric Fencing.

  • Powering your charger – consider which of the three sources best suits your particular situation.
  • Fence line – think about your fencing, steel wire gives less electrical resistance. Polywire, tape or rope draw more power from your system.  For tape or poly rope a low impedance fence controller is considered best.  For wire, fencing aluminum has less resistance than steel.
  • of wire strands – Multi-wire fencing gives less distance than single wire fencing. More wire over a shorter distance v’s less wire traveling in a straight line.  If you are using multi-wire fencing then you need to multiply the length of the fence line by the number of strands to get the length of wire you are powering.
  • Vegetation – have a think about how often that fence is going to be grounded and make sure you have enough battery power to keep it live.
  • Temporary or permanent – if you want a mobile fence system then AC isn’t your option.
  • Animal – think about what you are keeping in – larger animals need a stronger shock.

The heart of your electrical fencing system is your energizer – it powers the whole system.  When you are thinking about how to choose the right type of fence charger for your needs you must consider the whole system, the purpose, and the location.  Electrical fencing, with the right energizer, is a great and cost-effective solution.

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