A 2025 analysis of more than 22,700 electric vehicles across 21 models found that the average battery capacity loss was about 2.3 percent per year, according to the Geotab telematics company. That means these batteries still have more than 81 percent of their original capacity after eight years.
Waymo’s current fleet of nearly 4,000 vehicles is primarily made up of Jaguar I-Pace electric vehicles that have a 90 kWh lithium-ion battery. The company has also begun implementing the Oh robots manufactured by the Chinese automotive brand Zeekr with a 93 kWh battery.
“Let’s take a little cut in terms of degradation and the effective capacity that would be left in those batteries when they are suitable for reuse, and we’re still talking about pretty significant capacity per battery,” Hall said.
Waymo’s growing robotaxi fleet could generate “quite large amounts in terms of megawatt hours of capacity that can be deployed fairly quickly” for stationary energy storage that supports power grids, he suggested.
The agreement gives Waymo discretion over when and how many used batteries will be delivered to B2U. But the companies confirmed that B2U “has already begun receiving smaller initial quantities of batteries” from Waymo’s fleet. Over time, the deal could give B2U “hundreds of megawatt-hours” of additional storage capacity from Waymo’s thousands of electric vehicles, Lenz said.
Local network synergy
The B2U grid storage solution could do more than simply extend the usefulness of Waymo’s fleet’s lithium-ion batteries for several years. The new partnership is intended to support B2U projects in regions where Waymo’s self-driving robotaxis operate, meaning used Waymo batteries could boost local power grids that Waymo vehicles rely on for charging.
“What we think is really interesting and unique about this opportunity is that these are the batteries that help serve our riders in these communities, and then they go to BTUs to then be deployed on local grids that are close to the communities that we also serve,” Lenz told Ars. “So there’s a nice circularity here in our commitment to clean technology and supporting renewable energy in the grids.”
