If your paddock fence feels "dead" after heavy rain, the first step is not replacing the energiser—it is testing properly. An electric fence tester (sometimes called a voltage tester or fence tester) shows whether the pulse is reaching the line and where energy is leaking away. This guide explains how UK smallholders and horse owners can test safely, interpret readings, and fix the faults that forum posts often blame on the wrong component.

Why testing matters more than guessing

Electric fences work as a circuit: energiser → live wire → animal/soil → earth stake → energiser. When any part of that loop fails, voltage drops. Paddock owners frequently report readings near zero at the far end of a field while the energiser still clicks—classic signs of vegetation shorts, rusty wire, or weak earthing rather than a dead unit.

Testing saves money twice: you avoid buying unnecessary kit, and you find the weak link before stock tests the boundary. For horses, sheep or poultry, a reliable pulse is a welfare and liability issue—not just a convenience.

What you need before you start

• A dedicated electric fence tester (LED or digital kV meter—not a multimeter from the toolbox)
• Insulated footwear and dry hands; test when you can stand safely away from livestock
• Access to the energiser earth stake and a clear stretch of fence line

Many complete kits ship with a tester included. The FieldPro 12V/2J energiser kit with included fence tester bundles tester, insulators and posts—useful if you are setting up a new paddock rather than troubleshooting piecemeal.

How to test electric fence voltage step by step

1. Test at the energiser first

Disconnect nothing yet. Place the tester between the live terminal and the earth terminal on the energiser. You should see a strong pulse—often several thousand volts on the display, depending on the model. If output is weak here, check battery charge (12V leisure battery, not a flat car battery) and weatherproof connections before walking the fence.

2. Test on the fence line near the energiser

Clip or touch the tester between the live conductor and a metal earth stake (or the earth probe supplied with the tester). Note the reading. This is your baseline for a healthy section.

3. Walk the fence and test every 100–150 metres

Repeat the live-to-earth test at intervals, especially at gates, corners and dips where wire may touch grass. A gradual drop along the line suggests normal resistance; a sudden collapse at one point usually marks a short—broken insulator, overgrown vegetation, or wire touching a post.

4. Test the far end last

The end of the line is where problems show up first. If the energiser output is strong but the far end reads low, increase joule output if your stock requires it, improve insulators, or trim vegetation—not necessarily replace the energiser.

What voltage is enough for UK livestock?

Guidance varies by animal and fence type, but practical UK targets are:

• Horses: aim for at least 3,000–4,000V on polytape or rope; visibility matters as much as voltage
• Sheep: often need 4,000V+ because wool insulates; keep lower wires clear of grass
• Cattle: typically 2,000–3,000V once trained, but longer runs need adequate joules
• Poultry / fox deterrence: higher readings under load; wet grass on netting is a common culprit when testers show low kV

A 2.0-joule energiser such as the complete electric fence energiser kit on ElectricFenc UK (rated up to 15km, IP44 housing) is sized for typical smallholding runs where testers often reveal vegetation shorts rather than underpowered units.

Common causes of low readings (and what Reddit gets wrong)

Online threads often jump to "buy a bigger energiser." In practice, UK paddock faults cluster around a few repeat issues:

• Poor earthing: dry soil or a single small stake; add galvanised earth rods and dampen the ground if safe to do so
• Vegetation shorts: after mowing season ends, grass touching the bottom wire pulls voltage down—trim or raise the line
• Wrong battery type: car batteries drop voltage fast; use a deep-cycle leisure battery on 12V systems
• Corroded connectors: especially on temporary gates; clean clamps and use proper gate handles
• High-resistance tape: polytape needs tighter tension and good insulators; test after rain when tape sags

When to retest

Test after installation, after storms, and monthly during growing season. Log readings at the same fence points so you spot trends. A slow decline often means creeping vegetation; a sudden zero usually means a broken wire or gate left disconnected.

Recording results your yard team can use

Write down date, weather, battery voltage (for 12V units), and kV at three fixed points: energiser output, mid-fence, and far end. A simple table on the feed-room wall beats guessing after a storm. When readings drift down over two weeks without obvious damage, schedule vegetation clearance before ordering new hardware.

If you livery multiple paddocks, label tester readings by field name. That habit catches which gate handle fails first and stops endless debate about whether the energiser or the tape is at fault.

Safety reminders for UK sites

Electric fences must be installed and signed appropriately; keep energisers weatherproof and never modify units in ways that bypass safety standards. Use warning signs on public boundaries. If readings stay low after fixing shorts and earthing, consult a qualified agricultural electrician before increasing power beyond manufacturer guidance.

Frequently asked questions

Can I use a multimeter instead of an electric fence tester?

No. Standard multimeters are not designed for high-voltage pulses and can be damaged or give misleading readings. Use a tester rated for energised fence lines.

Why does my fence show voltage but animals ignore it?

Voltage under load matters. Test while the line is under normal conditions (wet grass, tape tension). Horses may also need more visible fencing; sheep may need higher kV through wool.

How often should I test a horse paddock fence?

Monthly in summer, weekly during stormy periods or when stock push boundaries. Always test after moving temporary lines or changing batteries on a 12V setup.