The Parmak Magnum 12 Electric Fence Charger, model MAG12UO, is a powerful 12-volt battery-operated fence energizer designed for medium to large pastures, remote fencing, livestock containment, high-tensile fence systems, and predator control.
Rated for up to 30 miles of electric fence and producing up to 3.1+ joules, the Magnum 12 gives farmers and ranchers AC-like fence performance without requiring access to household power. Parmak specifically designed this low-impedance battery fence charger to shock through weeds and brush while remaining portable enough for use almost anywhere on the farm.
That makes the Magnum 12 a strong choice for cattle pastures, horse fencing, sheep and goat enclosures, hog fencing, deer control, bear fencing, remote paddocks, and other locations where running 110V power to the fence simply is not practical.
3.1+ Joule 12-Volt Fence Charger
The Parmak Magnum 12 delivers up to 3.1+ joules of output and is rated to energize as much as 30 miles of fence. It uses advanced solid-state, low-impedance circuitry to provide strong fence performance while operating from a standard 12-volt storage battery.
For a battery-powered fence charger, that is a significant amount of capability.
Battery energizers are often used where electrical service is unavailable, but remote power does not have to mean weak fence performance. Parmak describes the Magnum 12 as providing output comparable to power-line-operated models, making it especially useful for larger off-grid fencing systems.
Built for Medium and Large Pastures
The Magnum 12 is designed for medium to large pasture electric fence systems.
It is well suited for:
- Cattle electric fencing
- Horse fencing
- Sheep fencing
- Goat fencing
- Pig and hog fencing
- Deer fencing
- Bear fencing
- Predator control
- Rotational grazing
- High-tensile electric fencing
- Remote perimeter fencing
- Temporary and portable pasture systems
Parmak recommends the MAG-12-U.O. for larger animals and larger pastures, and specifically identifies it as a strong choice for cattle, horses, hogs, sheep, deer, and similar applications.
Runs on a 12-Volt Battery
The Magnum 12 is powered by a 12V storage battery, giving you the freedom to install an electric fence charger in locations where AC power is not available.
Battery clamps are included, so the energizer can be connected directly to a compatible 12-volt battery. Parmak states that the Magnum 12 can provide up to three months of continuous operation between battery charges, depending on the battery and operating conditions.
That makes it useful for remote pastures, leased ground, temporary grazing areas, wildlife fencing, and fence lines located far from barns or electrical service.
Battery is not included.
Built-In Fence and Battery Performance Meter
One of the Magnum 12's most useful features is its built-in analog performance meter.
The meter displays the condition of both:
- The electric fence
- The 12V battery
This takes much of the guesswork out of maintaining a battery-powered electric fence. Instead of waiting until animals discover that fence voltage has dropped, you can check the meter and identify when the fence load or battery condition needs attention.
Parmak uses a digital meter on some of its larger AC models, while the Magnum 12 uses an analog performance meter designed specifically for its portable battery-powered system.
Shocks Through Weeds and Brush
Vegetation can quickly reduce electric fence voltage by allowing electrical energy to leak from the fence wire into the ground.
The Parmak Magnum 12 uses low-impedance circuitry designed to continue delivering useful fence power even when weeds and brush contact the wire. Parmak specifically recommends it for fences where vegetation may be present and describes the unit as capable of shocking through weeds and brush.
This is particularly valuable for summer pasture fencing, remote properties, and larger fence lines where keeping every foot of fence completely free of vegetation can be difficult.
High-Tensile Fence Compatible
The Magnum 12 is not limited to short portable fences.
Parmak specifically lists the MAG-12-U.O. as a high-performance low-impedance charger designed for high-tensile electric fencing, including multiple-wire systems.
That makes it a strong option when you need battery power for:
- High-tensile cattle fencing
- Multi-wire pasture fences
- Rotational grazing systems
- Remote perimeter fencing
- Wildlife exclusion
- Predator fencing
The combination of 30-mile capacity and 3.1+ joules provides substantially more flexibility than a lightweight battery fence charger intended only for small paddocks.
Weatherproof and Portable Outdoor Design
Unlike Parmak's AC fence chargers that typically require protected indoor installation, the Magnum 12 is designed for both indoor and outdoor use.
Its compact, weatherproof construction allows it to be installed directly where you need fence power.
That makes the unit especially useful for:
- Remote fields
- Temporary pasture setups
- Rotational grazing
- Seasonal fencing
- Predator-control fencing
- Farms without convenient electrical service near the fence
The portable design also makes it easier to move the energizer as grazing areas or fencing needs change.
Strong Voltage Under Load
The Magnum 12 is rated at:
| Specification |
Parmak Magnum 12 |
| Open Circuit Voltage |
13,500 volts |
| Voltage at 500 Ohms |
6,100 volts |
| Voltage at 100 Ohms |
3,100 volts |
| Maximum Output |
3.1+ Joules |
| Low Output |
1.1 Joules |
These manufacturer-published figures help show why the Magnum 12 is designed for larger livestock and predator fencing rather than small garden or pet applications.
Parmak Magnum 12 Specifications
| Specification |
Details |
| Manufacturer |
Parmak / Parker McCrory |
| Product |
Magnum 12 |
| Model |
MAG12UO / MAG.12 U.O. |
| Power Source |
12V Battery |
| Fence Range |
Up to 30 Miles |
| Maximum Output |
3.1+ Joules |
| Low Output |
1.1 Joules |
| Impedance |
Low Impedance |
| Open Circuit Voltage |
13,500 Volts |
| Voltage at 500 Ohms |
6,100 Volts |
| Voltage at 100 Ohms |
3,100 Volts |
| Display |
Analog Performance Meter |
| Battery Monitoring |
Yes |
| Fence Monitoring |
Yes |
| Installation |
Indoor or Outdoor |
| Weatherproof |
Yes |
| Battery Clamps |
Included |
| Battery |
Not Included |
| UL Listed |
Yes |
| Warranty |
3 Years |
Parmak lists the Magnum 12 as a weatherproof, portable 12V electric fence charger with a 30-mile rating, 3.1+ joules, and built-in fence and battery monitoring.
How Long Will the Magnum 12 Run on a Battery?
Parmak states that the Magnum 12 can operate for up to three months between battery charges.
Actual run time will vary based on:
- Battery size and condition
- Fence length
- Vegetation load
- Fence shorts
- Grounding
- Weather
- How heavily the fence is loaded
A clean, well-grounded fence with a healthy battery will generally require less energy than a heavily loaded fence with weeds, poor connections, or shorts.
Is the Parmak Magnum 12 Good for Cattle?
Yes. Parmak specifically recommends the Magnum 12 for cattle fencing and medium-to-large pastures.
Its 3.1+ joule output, low-impedance design, and 30-mile rating make it especially useful for remote cattle pastures and rotational grazing systems where AC power is unavailable.
Can the Magnum 12 Be Used for Horses?
Yes. Horses are one of Parmak's recommended applications for the Magnum 12.
It can power appropriately designed horse electric fencing in both permanent and portable pasture systems.
Is the Magnum 12 Good for Sheep and Goats?
Yes. Parmak lists both sheep and goats among the recommended uses for the Magnum 12.
Because wool and dense coats can make electrical contact more challenging, maintaining adequate fence voltage and good grounding is especially important for sheep fencing.
Can the Magnum 12 Be Used for Deer, Bears, and Predators?
Yes. Parmak specifically recommends the Magnum 12 for deer, bear, and predator-control electric fencing.
This is one reason the Magnum 12 is popular for remote agricultural and wildlife applications. A 12V battery allows the fence charger to operate far from utility power while still providing significantly more output than a small portable energizer.
Magnum 12 vs. Magnum Solar-Pak 12
The Magnum 12 and Magnum Solar-Pak 12 use similar high-performance fence-charging circuitry and share a 30-mile rating and 3.1+ joule output.
The main difference is how the battery is maintained.
The Magnum 12 runs from an external 12V storage battery that must eventually be recharged. The Magnum Solar-Pak 12 adds a solar panel and sealed rechargeable battery, allowing sunlight to maintain the battery automatically.
If you already have access to a suitable 12V battery or prefer a simpler battery-operated system, the Magnum 12 is the more straightforward option.
If the fence will remain in one remote location for long periods and you want automatic solar charging, the Solar-Pak version may be more convenient.
Why Choose a 12V Battery Fence Charger?
A 12-volt electric fence charger makes sense when you need serious fence power somewhere electricity isn't readily available.
Compared with a plug-in AC fence energizer, the Magnum 12 provides:
- Greater placement flexibility
- No need for nearby utility power
- Portable installation
- Outdoor weatherproof operation
- Compatibility with remote pasture systems
- Strong output for livestock and wildlife control
Compared with smaller battery-powered fence chargers, the Magnum 12 provides the output needed for larger fences and more demanding agricultural applications.
Shop the Parmak Magnum 12 at Shock Farm
The Parmak Magnum 12 MAG12UO Battery-Powered Electric Fence Charger combines 3.1+ joules of output, up to 30 miles of fence capacity, low-impedance technology, high-tensile fence compatibility, weatherproof construction, and a built-in performance meter in one portable 12V fence energizer.
For cattle, horses, sheep, goats, hogs, deer, bears, predator control, rotational grazing, and remote pasture fencing, the Magnum 12 provides a powerful alternative to a traditional plug-in electric fence charger.
