During a Munro Live teardown, Rivian engineers detailed how they slashed battery costs for the upcoming R2. The biggest savings come from switching to larger 4695 battery cells, which cuts the cell count dramatically from 7,776 in the original R1 down to just 776 in the R2.

To fit these taller cells without sacrificing interior space, Rivian integrated the cabin floor directly into the top of the battery pack. This reclaimed vertical room allowed for a simpler venting system, fewer pressure valves, and a stiffer structural frame—creating a fully sealed pack that is both cheaper to manufacture and easier to service via a separate module under the rear seats.