Deer are strong animals that tend to strike at night - so do not get the S10, S16, S20, or S40. These energizers are great but they are not meant for keeping deer away. The chargers have a day/night sensor - so at night time, the pulse rate drops to conserve battery life.
You will need an energizer that can put out at least 1 joule of energy. It's okay if it's slightly under a joule.
We recommend the following products for keeping deer out:
Fencing: Consider getting Turbo Tape. It's visible, so deer can see it, and it's WAY MORE conductive than poly tape.
Posts: Use Fiberglass Rod Posts where a stronger, stiffer fence post is required .