Renault tried leasing the batteries in EV in an effort to lower the initial cost of the car while increasing their tail for future owners. They abandoned it only a few years in as it was a disaster for their used market that got worse the older the car got as nobody wanted the ongoing cost. Only the initial owner saved money, and only if they managed to use PCP finance with a balloon set before Renault realised that the battery leased cars would be worth significantly less.

Renault also did not like that with older cars they would be liable for the battery replacement far sooner than they planned as they (initially) had a higher percentage unusable before they had to do a free replacement vs. a normal battery warranty, made worse as a leased battery has a warranty as long as you are paying the lease.

Renault could repossess the car if you stopped paying the battery lease and refused to buy it out. Its like any car finance that puts a lien or similar on the car, you do not own it till its gone.