I am running 2 wire electric fence on all my interior fences . Bought a load of posts a grain farmer pulled out 10 years ago for next 2 nothing, with no pressure on the fence , cows reaching through I think I will get another 20 years out of them. I can put up a mile of fence in a afternoon and they never cross it. Make sure I have a good slant brace at each end and some places I get up to 100 feet spacing on posts