EV battery cooling tech has come pretty far in the last 30 years. The GM EV1, for instance, was reengineered in 1999 with an air tunnel to properly cool its optional nickel-metal hydride (NiMH) ...
Kia EV9 high-voltage battery pack teardown by Munro & Associates reveals engineers likely thought about repairability when designing it. There are two access plates underneath for serviceable items.