Tesla’s ambitious 4680 battery cell project, introduced with bold promises in 2020, is struggling to meet expectations. Independent data and user reports reveal lower energy density, reduced driving range, and poor fast-charging performance, particularly as Tesla shifts to these cells in European Model Y vehicles.
- 4680 cells deliver 13% lower energy density than Panasonic 2170 cells
- European Model Y range drops 8% after switching to 4680 batteries
- Charging performance trails behind previous supplier batteries
What happened
In 2020, Tesla unveiled its 4680 battery cell with groundbreaking promises, including 5 times the energy, 6 times the power, and a 16% improvement in vehicle range. The cells featured a larger diameter and a novel 'tabless' design intended to revolutionize battery performance and manufacturing efficiency. However, after five years of production and testing, the 4680 cells have not met these forecasts.
Tesla has been swapping out supplier battery packs, such as LG’s 5M and Panasonic’s 2170 cells, for its own 4680-based packs in European Model Y vehicles. Independent performance data and driver feedback indicate Tesla’s cells underperform in key metrics including energy density, usable battery capacity, range, and especially fast-charging capability. These issues are becoming impossible to ignore as more owners experience the downgrade firsthand.
Why it matters
Tesla’s 4680 battery cell program was designed not just for performance gains but also to reduce manufacturing complexity and lower costs, including enabling a $25,000 electric car price point. Falling short on these goals threatens Tesla’s competitive edge in the rapidly evolving EV market. The lower energy density and reduced range on the same Model Y platform represent a setback for customer expectations and Tesla's promise of continual improvements.
Charging performance is particularly critical for Tesla’s fast-charging network convenience. The 4680 cells exhibit significant heat buildup, causing charging power to drop early in the charging cycle and extending overall charging times well beyond previous battery packs. This degradation in fast-charging responsiveness could impact Tesla’s appeal to existing and prospective buyers who prioritize quick recharging during travel.
What to watch next
Tesla has acknowledged challenges with the dry battery electrode manufacturing process critical to the 4680 cell, with CEO Elon Musk calling it much harder than anticipated. Future updates from Tesla on cell chemistry, design improvements, or manufacturing enhancements will be key to monitor. Independent verification of any claimed improvements in energy density or charging performance, especially on new versions of the cells, will be closely scrutinized.
Market reaction and customer feedback in Europe and other regions where 4680 packs are deployed may influence Tesla’s supply chain and product strategy. Any continued performance shortfalls could pressure Tesla to reconsider its long-term approach to battery manufacturing and partnerships with external suppliers, impacting EV production costs and timelines.