Not ideal to cut power to the entire car, but that happens anyway on every battery swap, no? If you want to get fancy you can isolate the exact fuse and switch

Not ideal to cut power to the entire car, but that happens anyway on every battery swap, no? If you want to get fancy you can isolate the exact fuse and switch just that: https://www.ebay.com/itm/175668177479 https://www.ebay.com/itm/175668177479 Thinking more, given how common parasitic drains are, carmakers should have all non-essential fuses in a separate subpanel section that can be easily switched off/diagnosed.