All a gas station needs to do is hold enough batteries to match the rate of customer arrival over the time it takes to recharge a battery, plus a safety factor

All a gas station needs to do is hold enough batteries to match the rate of customer arrival over the time it takes to recharge a battery, plus a safety factor of X. Stations can add more batteries to their pool over time as more people start driving electric vehicles. And instead of daily fuel tankers, occasionally a truck comes to the station with replacement batteries for those detected to be worn out. It could be a really great system if Tesla makes it easy to setup and handles most of the work automatically delivering new batteries when demand increases, and replacing worn out ones. Someone should do the math of how many 'equivelent fill ups' it takes to pay for a battery, and then subtract that from the total amount of fill ups possible before wearing out and electricity cost. I have a feeling this could be a very profitable investment.