Rivian surprised everyone today by not only revealing the highly anticipated R2 SUV at a starting price of just $45,000, but also showing us another car, the R3, as well as a new battery cell that underpins both cars. The cell is called 4695 because of its diameter of 46 millimeters and height of 95 millimeters. Its specs haven’t been detailed yet, but it’s considerably larger than Tesla’s 4680 cells, which could mean a lot of things.
As battery cells get bigger, their voltage doesn’t change unless the chemistry changes, and Rivian is more likely than not using conventional lithium-ion chemistry. What goes up is the cell’s amp-hour rating, which translates to a 4695 containing more energy than a 4680. But there’s more.
Larger cells can generally charge and discharge at higher rates. In short, this means the R2 will likely be able to charge faster and deliver more peak power than if it got its juice from a slightly slimmer pack consisting of 4680s. The car’s regenerative braking can also be more powerful, which can offer efficiency gains.
Rivian is not the first to get into the 4695 game. BMW recently revealed samples of a 4695 cell that it plans to use in its Neue Klasse of electric vehicles starting in 2025. Indeed, several Battery manufacturers now produce cells in this 46mm format, including Samsung SDI, Panasonic and LG.
We don’t know the exact specs of these new 4695 cells, but we can make a small guess at the pack’s specs based on the images Rivian showed us during the reveal.
Zooming in on the pack, it appears to be made up of 3 large modules separated by heavy internal frame rails. Each module measures 34 cells wide by 8 deep, for a total content of 272 cells. If we’re talking about lithium-ion and assume the cells are all wired in series, we get a module voltage of 979.2 V (nominal). This is a 1000V architecture, not 800V as speculation might indicate.
With three of these wire modules in parallel, the voltage will remain the same but the available current will increase considerably. We don’t know the ratings of each cell, but the other 4695s are capable of discharging pulses up to 10°C, or ten times their amp-hour rating. This could mean available power of up to 900 kW, or around 1,200 horsepower. However, the Rivian’s 4680 likely prioritizes capacity, so such high discharge rates are unlikely.
Once the electric automaker reveals the pack’s total capacity, this type of information can be extrapolated. For now, just know that these new battery cells will likely enable performance equal to, or even better than, what Tesla is capable of in cars like the Model Y. How efficiently the rest of the drivetrain uses this energy will have of importance in terms of real energy. -global performance, but kilowatt hours are within reach.
