Every large villa has one: the convertible, the big SUV kept for desert weekends, or the car bought for a teenager who is away at university. It does forty kilometres a month. Between drives its alarm, tracker and keyless system keep drawing current, and the battery spends most of its life partly discharged, which shortens that life.
These are also the cars with the least obvious batteries. On many European models the battery is in the boot floor or under a seat, it is AGM, and the car expects the replacement to be registered. The technician handles all of that in your garage, with a memory saver connected so seat, radio and clock settings are kept where the car allows it.