Portable Electric Bear Fences For Any Adventure

How does an electric bear fence work?

by Cynthia Gentles
A Bear Sentry is an example of a simple electrical circuit. The polywire is connected to the positive ( + ) terminal of the energizer; all the lines are ( + ). The ground stake is connected to the negative ( - ) terminal of the energizer; all of the ground underfoot and paw is ( - ).
The electrical circuit of the Bear Sentry portable bear fence where the circuit is open. There is no connection between the positive and negative poles of the 1.8 Joule stored Bear Sentry energizer.

The fence is an open circuit when there is no connection between the ( + ) and ( - ) poles of the energizer. Nothing happens.
A hunting camp protected by a Bear Sentry electric fence.

When an electrically conductive body like a bear contacts a “hot line,” it becomes the missing link between the fence (positive) and the ground (black).

The Bear Sentry energizer discharges 1 Joule of electrical energy through the conductive body of the bear, to ground.


The bear completes the circuit between the ( + ) and ( - ) poles of the energizer.

A bear receives a 1.0 Joule shock in the form of a split second pulse and is deterred from entering a campsite.

A huge 1.0 Joule pulse of electrical energy flows from nose to paws to ground for a split second. Shocked, the bear runs away. Deterred, it won’t come back.

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