Friend and I were having one of those what-if thought experiment conversations about Tesla recharging. We wondered how high/steep/long an imaginary incline would have to be in order to fully recharge a Tesla. I guess a part of this would be to determine how steep a hill has to be in order to effectively regeneratively charge continuously. Anyone have any ideas how best to come up with an approximate answer? Obviously this question is just for fun and not intended to be anything other than a thought experiment.