I remember as a kid seeing a radio under a bucket in my grandparents garden. This was their tried and true method of deterring deer ... and it worked! I have been using this same method myself and I have had a few people ask me where did I get mine as I have an usual setup. Like most people a plugin is nowhere near the garden so usually others use a radio and are constantly changing out batteries. This is such as waste of resources and if you try and buy a solar powered radio you will find out that they are just a gimmick as the solar panel supplied usually isn't enough to keep the radio going.
I have come up with a solution that is self sustainable and will last through several days of rain. The trick is having enough battery pack to last and a solar panel that is large enough.
Lets get started ...
Step 1: The Parts
This is more of a plug and play build. Lets review the parts:
1) the container: any rubber type container will do. Mine is a little big but I was trying to use what I had. These can be found at many local department stores
2) weight it down: you don't want it blowing away in the wind. I added some rocks and some logs in the bottom in case water got in things wouldn't short out. I suggest drilling couple holes in the bottom to let the water out if it does find its way in
3) the solar panel: this captures the suns power. I find Gomadic's system is the easiest to use. Start with 10W solar panel sold here Then you need this Gomadic SunVolt circuit that converts the power to charge the battery pack. Next a Gomadic Lithium Ion rechargeable battery pack to store the sun's power for use over the night and next couple days if it is raining. Tape the solar panel to the top and drill a small whole in the side of the container to route power through.
4) playing a persons voice to keep the deer away: I used a Gomadic mp3 player speaker which isn't sold on their site anymore but I think this is a good substitute sold here on Amazon. You don't need to have a loud speaker rather just loud enough to scare the deer away from the immediate area. Look for any mp3 that is a person talking. I found some on a public radio station's website like found on this page
5) Plug the solar panel into the SunVolt circuit, then into the battery pack then finally the MP3 player into the battery pack. Enable repeat on the mp3 player and press play. You may have to 'wake' the battery pack using the power button on the pack.
Step 2: Lets Review
The idea is you put the mp3 player on loop and turn the volume to a medium loudness. Place the box in the middle of the garden and the deer should stay away. It works in my garden. I live outside of town in the northern part of Minnesota where the deer are a constant nuisance to gardens. If you are still having problems then I think a small fence and radio combination should do the trick.
Things to watch out for in this design. If you have several weeks of rain the pack may go dead resulting in the mp3 player will stop. When the sun is out again I don't think the mp3 player will automatically start again. Turns out that the Gomadic speaker will restart but again they no longer sell it. I have not tested the player I linked in this build so if you find a better mp3 player that will automatically start let me know so I can update this post.