Solar Powered Fence Charging Station
Over the past couple of years I have made some major changes and improvements to my electric fencing projects. You can see my original, more modest efforts here
. This is still a good page to get the basics. However, I have migrated away from fully electric fence for the goats. The fence worked just fine for them, however, the thick brush was impossible to keep clear of the fence lines and periodic flooding also occurred so the fence continually grounded out.
It is really hard to run electric fence through this! It periodically floods, is almost always swampy and the weeds grow up seemingly overnight!
Ironically, my main “brush clearing” employees (the goats) were so afraid of the electric fence, they wouldn’t go near it. As such, the weeds quickly grow up and shorted it out. I briefly gave up on electric fence and instead I switched to 4 foot welded wire on T-posts. However, the goats quickly learned to “climb” this fence to reach tasty branches on the other side and thus collapsed it, so I needed to retain one electric wire to keep them off and away from the fence. However, I am able to keep this hot wire high enough off the ground to reduce some of the pressure from weeds. In the really swampy area, I have a few knife switch cut-offs, so I can shut this section off during high weed season, the cattails and phragmites grow tall enough to put heavy pressure on the fence.
I did however, find a new purpose to expand my electric fencing project. I have converted a half acre plot into a small orchard and this is also a nice place to have my chickens free range in the grassy area. I have a five foot tall welded wire fence enclosing this area completely, but the foxes very soon figured out it was easy to dig underneath to start grabbing the hens. I quickly grew tired of plugging all their holes as it was a never ending task and the thought of extending the fence underground along its entire length was just too daunting (particularly with all the tree roots and fieldstones everywhere). As such, I put one hot wire very close to the ground to stop any digging activities.
Anti-Predator electric fence wire about 6-8 inches off the ground running along the outside perimeter.
I was a little nervous about it shorting out (as per above), but this area of the farm is a little shadier along the fence line (under a heavy tree canopy) and thus the weed pressure is a lighter, also since it doesn’t go through the swampiest areas, it is easier to maintain once in awhile with a weed whacker. So far it seems to be working.
The materials I needed to do this are as follows:
- Homemade electric fence brackets made of PT 2X4
- Screw-in plastic insulators for wood posts
- Nylon wire tensioners (not the steel type for high tensile fence)
- 18 Gauge Aluminum Fence Wire (recycled from my goat fence project)
- 2’ and 4’ sections of rebar for tricky areas
- Rebar electric fence insulators
- ½” Black HDPE irrigation pipe (to insulate wire that needs to snake through another fence) and zip ties
- Electric fence gate handles and anchors
- Assorted hardware including 3” galvanized wood screws
Regarding the homemade electric fence brackets, I needed these because I wanted to use the existing wood posts to hold the electric wire. However, I have always found that if I just used the screw in plastic insulators directly on the post, the electric wire was always too close to the welded wire fence and shorted out. Even the slightest bowing of the welded wire would cause it to come in direct contact with the electric wire. A small branch falling on the hot wire would push it against the fence too. There doesn’t seem to be a cheap and ready-made product to make the hot wire “stand-off” a bit from the fence so I made my own. Basically, I have been saving all my PT 2X4 scraps from my fencing project and cut them into 8” pieces for the base and 4” pieces to hold the insulators. Of course, I painted them all green to match the fence posts.
Making my homemade electric fence brackets, assembly line style!
These really help to keep the hot wire a good distance from the actual metal fence and make it just that much more difficult to short out, yet also keep predators away.
Once I had my brackets made, it was easy enough to screw a plastic insulator onto the end of each one (I used two insulators on corners, as there is more pressure) and then screw the bracket onto the fence post so the hot wire was about 6 or 8 inches from the ground.
Fence bracket in action. This one requires two insulators as it is rounding a corner.
So I went along like this, but invariably there were some irregularities. In areas where my fence was bowing out too much and hit the hot wire… well, I pounded in some rebar stakes to hold it back.
Rebar holding back the welded wire fence to prevent shorting it out.
In areas where I needed to go through an adjoining fence, I put a section of HDPE pipe and a couple zip ties to act as an insulating conduit.
A small length of HDPE irrigation pipe to act as an insulating conduit.
In a few areas I needed to put small rebar stakes with an insulator to help hold the hot wire away from trees and other obstacles.
Rebar stake to help position the wire "exactly" where it needs to be.
Another piece of rebar with an insulator to help me weave the wire through some existing trees.
I also have several gates that needed to be addressed. For gates that are used for tractor access, I obviously needed an electric gate that can be disconnected an moved. For “human” gates, this wasn’t really necessary, as it is just as easy to step over this low wire as it is to disconnect a gate. You can buy a fancy kit that has spring-type wire for the gate, but I find it easy enough just to double over some regular aluminum wire and use just a simple handle with a pair of gate anchors at either end. This will only run you about 5-10 dollars or so.
Close-up of customized gate hardware mounted on my fence bracket.
Also, I added a lightning arrestor, and a handful of nylon fence tighteners to help me keep the wire from sagging.
A ceramic lightning arrestor attached to a ground rod. Hopefully, this will spare my charger in the event of a lightning strike (has not happened yet!).
Close-up of the lightning arrestor. This is one time use, and will need to be replaced in the event of a lightning strike (think of it as a fuse).
In the end, by hook or by crook, I got all the wire hung (maybe 800-1000 feet, something like this). This system has been working great for me. It has been in place for nearly two years, and there hasn’t been a single hole dug under the fence. About once a week I check it with my Zareba “Fence Doctor” to check the voltage and determine if there are any shorts.
The "Fence Doctor." This is worth the money for long fences. If your fence is short, get a basic tester for much less.
If you are going to have a significant amount of electric fence (I would say over a 4-500 feet), I highly recommend getting a “Fence Doctor” or similar high end fence tester. It was a bit pricey at over a hundred bucks, but if there is a short it will indicate in which direction you can find the short. This can save you a significant time and energy when trying to find that one little branch that is pushing on the hot wire. If you have a shorter fence (say maybe just a around a small chicken run) it is a waste of money. Just get a regular voltage tester and you will be fine.
One unforeseen issue I have had is with (if you can believe it) snow in the winter... It tears my homemade fence brackets and knife switches apart! For two springs now, after the snow melts away I have encountered multiple broken fence brackets (the two 3” wood screws are that hold these brackets together literally snapped in half). Originally, I thought maybe someone was standing on the brackets as a convenient step to try to scale the fence (what else could snap steel wood screws like this?). However, I think I have figured this out. In the winter, the snow drifts against the fence (sometimes 3 or more feet deep). The sun melts the top layer of the snow during the day that then refreezes at night into a solid sheet of ice an inch or two thick on the top. Eventually, the underlying snow either melts or blows away and this enormous sheet of ice is now resting directly on the fence wire and it snaps the holders as it weighs hundreds of pounds.
Similarly a couple of cut-off knife switches have been pulled apart at the plastic base. I think what happens here is that the reeds have grown up over the wire and then died back in frost and end up draped over the wire. This catches the snow and ice and just like with the brackets, the weight pulls the switches apart. So in order to prevent this, I put a couple of screw in insulators in front of the switches to take the additional strain off of the switches directly. So far, so good on this fix.
Protecting my delicate cut-off switches from excessive strain by tying the wire off on two separate insulators.
In both instances here (if you can believe it) the tensile strength of the aluminum wire is such that the wire remains intact as the brackets and switches give way first. I just prepare to replace a few of these each spring after the thaw before turning the fence back on for the season as there is probably no other way around this.
I have also made major upgrades to my fence charger and solar power system.
This is my original, basic fence charging station. This had a single battery, a 15 watt solar panel, a 7 amp charge controller, and a 1 joule fence charger.
This is my second fence charging station near the orchard. Likewise, this had only a single battery, and the most basic solar panel and charge controller. The 2 joule charger, quickly drained the battery.
I have doubled the power of my fence charger from 1 Joule to 2. This particular charger is rated for 50 miles of fence (with only a single wire, I don’t think I even have half a mile of wire). However, the extra power gives it more resistance to weeds, as well as over 10,000 volts to keep the predators at bay and the goats contained. I also had two separate “fence charging stations” for each location (orchard and goat field), that I consolidated into one. I built this charging station directly into the fence and this keeps everything dry and protected.
This is my consolidated, comprehensive electric fence command center. the doors close up to keep it relatively weather proof.
1. On/Off switch (just a regular household switch)
2. 2 Joule fence charger
3. 30 amp solar charge controller
4. Plastic box to store my fence tester
5. 3, 105AH deep cycle batteries wired in parallel
6. Can of Hornet Spray, as my fence charging station doubles as a "hornet house". They love it!
Using a two knife switches on the hot wire, I can have either or both locations electrified and it can all be turned on and off from one central location.
Two stainless steel knife switches that control the goat and orchard areas independently.
The downside of this power increase is the fact that my single 15 watt solar panel (amorphous silicon) has absolutely no hope of competing with the battery drain.
My original, vastly underpowered, 15 watt, amorphous silicon solar panel.
With both areas electrified and a moderate weed load, the battery would drain down in a month, even with good sunlight. It was particularly bad in the fall when the weeds were full grown but the day length is growing shorter, and thus, less sun for the panel.
I played around with adding a few more 15 watt solar panel (as they are relatively cheap and available at Harbor Freight Tools). However, I finally gave up with these and bought some “real” solar panels. I ended up upgrading to three Renogy 100 watt monocrystalline solar panels (for a .3 kilowatt array).
My upgraded 300 Watt monocrystalline solar panel array.
I also needed to upgrade my solar charge controller from a 7 amp to a 30 amp to handle the extra output of the panels. Lastly, I added an additional battery, giving me about 315 amp hours of power (a good reserve). So far, this has easily kept pace with the output from the new charger and additional strain of the larger area even with weeds.
All in all, I am happy with these upgrades, and my fence is easily able to keep foxes and other animals from digging under the fence and my goats respect the fence as well.