Tesla has intentionally left space in the battery pack of its Cybercab, a design aimed at launching cheaper robotic taxis in the future. Robert Sumpf, the mechanical design engineering director for Tesla's battery modules and packs, explained that the extra space beside and below the Cybercab module is intended to allow the company to switch to lithium iron phosphate (LFP) batteries in the future. "Thus, we protect this battery pack to adopt lower energy density chemistries when scaling up and to introduce LFP to the platform," Sumpf said during an in-depth discussion of the Cybercab with Munro Live.
The Cybercab currently operates on Tesla's own 4680 batteries, which use nickel-based chemistry. LFP batteries have relatively lower energy storage, so a direct replacement would reduce driving range. The reserved space allows Tesla to add more LFP batteries to compensate for this gap. In contrast, Tesla would benefit from a battery that is cheaper, operates at lower temperatures, and can withstand more charging cycles. Last year, LFP became the most commonly used electric vehicle battery chemistry worldwide.
Tesla Cybercab Plans to Launch LFP Battery Version in the Future
Not all of the reserved space is intended for chemical changes. Lars Moravy, Tesla's vice president of vehicle engineering, noted that some of the space exists because "we don't need as many batteries as originally anticipated." Tesla told Sandy Munro in early 2025 that their goal is for the Cybercab's battery pack to be below 50 kWh while achieving a range close to 300 miles. The design of this battery pack also differs from Tesla's structural designs in certain Model Y and Cybertruck vehicles.
The Cybercab uses four independently sealed modules instead of packaging hundreds of batteries into a single block, allowing for the replacement of faulty modules without scrapping the entire battery pack. Sumpf rated the old design approach as "D grade" due to its difficulty in construction and near impossibility of repair. He estimated that a fully structured battery pack could increase battery capacity by about 10%, but stated, "The issue is the cost of repairs."
This cost is particularly significant for a vehicle that is rarely parked. Eric Earley, the chief engineer of the Cybercab, stated that replacing the entire battery pack before reaching 500,000 miles "is financially fatal," which is why remanufacturing and repairability were considered from the start of the design. During the same visit with Munro Live, Moravy acknowledged that the progress of the Cybercab product line at Giga Texas in Texas has now surpassed the deployment of Robotaxi and introduced the unconventional painting process for the robotic taxis.
Tesla aims to deliver the first batch of Cybercabs to external customers by the end of 2026, although Elon Musk indicated that the vast majority will still be owned by Tesla and operated as a transportation service. Sumpf did not provide a specific date for the LFP version, nor did he mention how battery suppliers or chemical changes would affect driving range. Currently, the 4680 series vehicles continue to accumulate: records from the Texas Department of Motor Vehicles show that as of Tuesday, 544 Cybercabs have been authorized to enter Tesla's Robotaxi fleet, marking the first time the number has surpassed 507 Model Ys.