Tesla is introducing a new $0.40-per-minute penalty for customers who leave their cars parked in Supercharger charging spots beyond the required charging time.

After a five-minute grace period expires, the flat-rate fee would kick in, dissuading Model S and Model X owners from hogging the space, Tesla explained in a mid-December press release.

After some resistance to the new penalty structure, Tesla CEO Elon Musk altered the fee structure such that all fees will be waived if most of the charging spots at a given location are empty, reports Electrek.

“We are going to modify this so that people only pay a fee if most bays are occupied. If the site is basically deserted, no problem to park,” said Musk in a December 17 post on Twitter.

Tesla says the move to charge drivers for unnecessary idle time at charging stations is based solely on improving charger access for all customers, and is not principally intended as an additional revenue stream.

“To be clear, this change is purely about increasing customer happiness and we hope to never make any money from it,” read an excerpt from Tesla’s press release.

Tesla is also discontinuing free use of its supercharger networks for new customers as of January 1.

Using its autonomous drive technology, the company plans to develop charging protocol wherein cars move themselves out of charging spots and into parking spots once charging is complete, though the technology required to facilitate this is not yet perfected.

(Tesla via Electrek)