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Electric fence energiser buying guide

Updated: October 2026

You are looking at a paddock tape, a poultry net, or a single garden wire, and the box says 10 km. That distance is the wrong first number. An electric fence energiser buying guide for a UK field starts with output energy, whether you have a safe 230 V socket, and whether the earth rod is in the carton. The unit releases a short pulse, about once a second, so stock learn to stay off the wire. The [electric fence energiser comparison](/hub/fencing-and-wire/electric-fence-energiser) is the model table for this amazon.co.uk set, with shelf prices from about £36 to £140 on 19 October 2026.

You are looking at a paddock tape, a poultry net, or a single garden wire, and the box says 10 km. That distance is the wrong first number.

Our top picks

FenceMate FenceMate 230 V 0.5 J mains energiser

Best overall

FenceMate FenceMate 230 V 0.5 J mains energiser
5.8/10about £35.99
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FenceMate FenceMate 12 V 0.5 J energiser

Best value

FenceMate FenceMate 12 V 0.5 J energiser
7.4/10about £49.99
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XSTOP XSTOP BA80 12 V electric fence energiser

Rank 3

XSTOP XSTOP BA80 12 V electric fence energiser
8.2/10about £54.99
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On this page
  1. 1.What the energiser actually does
  2. 2.Joules before kilometres
  3. 3.Mains, battery, or solar
  4. 4.Earth, weather rating, and box contents

What the energiser actually does

An energiser is the box that makes the pulse. Listings also call it a charger or a fencer. The live terminal feeds the wire, tape, or net. The earth terminal feeds a rod in the soil. When an animal touches the live wire, the pulse returns through the ground. If the earth is poor, the animal may feel little even when you hear a click. Do not electrify barbed wire, and use one energiser on one fence.

Joules before kilometres

Output joules reach the fence on each pulse. Stored joules are the larger capacitor figure. Compare output with output. AHDB’s rule of thumb is about one stored joule for 5–6 miles of 2.5 mm high-tensile wire, or about one mile of polywire, at 4,500 V. Compel’s starting bands differ: under 1 joule for a garden or short poultry net, 1–2 for clear horse tape, 2–4 when grass touches cattle wires, and 4 and up for sheep in wool. Do not average the two methods. A 10 km or 24 km line is usually a clean single wire. FenceMate splits its claim: about 2 km in average conditions, and a longer figure only on a clean wire. Models are on the joules page.
FenceMate FenceMate 230 V 0.5 J mains energiser

Testsieger

FenceMate FenceMate 230 V 0.5 J mains energiser
5.8/10about £35.99
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Mains, battery, or solar

AHDB treats mains as the usual first choice beside a real supply. Voltimum wants one energiser per fence, an RCD not exceeding 30 mA, and a socket that keeps its weather protection with the plug in. One AUSTUFF reviewer said the plug, with its 12 V transformer, would not sit in a covered outdoor socket. A doubtful spur or a wet yard socket is an electrician’s job. A 12 V unit is the moving fence. AHDB prefers a leisure or marine battery, and it is usually not in the box. Rutland’s guide says a recharge about every one to four weeks, depending on load. Solar here is about 0.25 joule plus a UK adapter. Size the panel for December, not June. The versus is the mains or battery page.

Earth, weather rating, and box contents

Rappa’s rule of thumb is about one metre of rod per joule, at least 10 metres from any other earth. A poor earth is the usual reason a fence does not shock. Do not use a water pipe. A 50 cm rod on a 0.25 joule solar unit can be enough in damp soil and too short when it dries. Read the components line, not the photo. Tuotian reviewers did not receive the stake the pictures implied, and Briidea lists included components as none. IP54, IPX6, and IP44 are not the same claim. Near a footpath, AHDB and Cornwall Council say signs every 50 metres or less. Shropshire uses about 100 metres when the fence only runs alongside a right of way. The cheap end of this set often omits the rod. If you buy through a link on this page, we may earn a commission at no extra cost to you. There is no lab test.

Common questions

How many joules do I need before I look at kilometres?
Start with output joules if the listing prints them, and treat stored joules as the larger capacitor figure. Pick one method, Compel’s output bands or AHDB’s stored-joule rule of thumb, then check voltage on the wire with a tester. A 10 km title is not that check. The two methods do not agree, so do not average them into one official formula.
Should I compare stored or output joules?
Compare output with output when both listings state it, because that is the energy described as reaching the fence. Stored joules are higher, and AHDB prefers them as a catalogue number. The My Animal Command solar listing prints both: 0.25 joule output and 0.55 joule stored. Do not add them, and do not treat a listing that prints only one of them as equal to a listing that prints the other.
Is the earth stake in the picture actually in the box?
Often it is not. The included-components line is the line that counts. FenceMate’s 12 V unit and the XSTOP BA80 name a stake. Several 2 joule and 3.5 joule titles do not, and reviewers have said the rod was missing. If the line says only the energiser, budget for a rod and leads before you compare the shelf price.
What voltage should I measure for cattle or sheep?
AHDB gives 4,500–5,500 V for untrained cattle, 3,500–4,500 V once they are trained, and about 5,000 V to train sheep in wool. Gallagher’s UK page says at least 3.5 kV to keep animals in and 4.5 kV to keep wild animals out. Measure at the far end with a fence tester. A light on the energiser is not that reading.
Does a pulse light prove the far end is live?
No. The LED, and the click, show that the unit is trying to pulse. Grass, a poor earth, a broken connection, or too little output for polywire can leave the far end weak while the light still flashes. Walk the fence with a tester after you connect it, and again when growth comes up in summer.

Related pages

How to set up an electric fence energiser

Fence tester

Electric fence energiser

Best electric fence energiser: who should skip one

Electric fence energiser joules for stock and grass

Mains or battery electric fence energiser for the UK

Sources

Public UK sources from the research digest. Listing prices, stars and review counts are the amazon.co.uk lines used for this comparison, retrieved 19 October 2026.

  1. AHDB — Components of an electric fence (retrieved 19 October 2026)
  2. AHDB — How to set up electric fencing for cattle and sheep (retrieved 19 October 2026)
  3. BSI — BS EN IEC 60335-2-76:2021+A11:2021 (retrieved 19 October 2026)
  4. Voltimum UK — Installation requirements for electric fence energisers (retrieved 19 October 2026)
  5. British Horse Society — Electric fencing (retrieved 19 October 2026)
  6. Cornwall Council — Electric fence guidance for landowners (retrieved 19 October 2026)
  7. Compel — Electric fence energiser (retrieved 19 October 2026)
  8. Rappa — Guide to earthing (retrieved 19 October 2026)