Solar Powered Electric Fence

Part of moving the bees to our place in the country is so they can be out of town and away from people.  Of course, getting away from people means getting them closer to good old mother nature herself.  For anyone who has read Winnie the Pooh, you know that bears like honey when they get a rumbly in their tummies.

Bears don't read very well...

Not much will really stop a hungry bear, but the official recommendation is to enclose all “country bees” in an electric fence.  When a bear attacks a hive, the bees always come out in great number to ward off the attack.  Bear fur is typically too thick to present a problem.  The only sensitive place on a bear is apparently their nose/mouth area.  While my electric fence is a little more “juiced” than a bee sting, most folks agree that a bear has to learn about the fence with their mouth or nose.  I’ll talk more about that another time, but it makes sense that an electric fence properly set up should deter all the Poohs out there.

So, you may be wondering how solar power can deliver enough juice to make a bear even notice it was there.  It turns out that the people who make electric fence controllers make a version that runs on DC (i.e. deep cycle batteries, not house current which is AC).  The controller I bought is designed to power up to 25 miles of fence.  All told, I have maybe 1000 feet of wire strung on a few poles, so the charger will deliver a good shot when it fires.  I won’t bore you with the calculations about the capacity of the battery but it is roughly the size of a car battery just for perspective (a car’s starter battery would not work here though…this application needs a long continuous  draw on the battery rather than the quick hit when you start a car)

The battery, fence controller, and charge controller

The instructions show that the fence will run for 2 weeks on a fully charged battery of the proper specs but I do not want to have to worry about whether the battery is still charged if I don’t make it out there for a few weeks.  Instead, I bought a solar panel and a charge controller to keep the battery full.

See? It's pointed south

I pointed my solar panel south and angled it to the optimal angle to get direct sun.  Output wires from the panel go into the charge controller which regulates the power going into the battery.  The charge controller makes sure the power is the proper voltage and that the battery does not get over or under charged. The charge controller also has a “load” connection so I connected the fence controller to that connection and we’re off and running!  All of the charging/controlling/shocky-shocky stuff is inside a beehive surrounded by my other beehives as a sort of a theft deterrent.

Oh, by the way, without thinking I tried to use a regular household switch at the gate to turn the power on and off.  Of course, the fence controller pushes somewhere around 10,000 volts which didn’t even slow down for the switch rated for household current of 110 volts.  If you want a switch, make sure you get one rated properly…same with any wire you may need to use (I only used fencing wire which handles the charge nicely)

So, I hope some of that makes sense.  So far it is alive and well.  Let me know if you want more details…