How Tesla’s Batteries and the 4680 Cell Work
From the 4680 cell to the grid-scale Megapack, Tesla treats the battery — and the factory that builds it — as the core product. Cheaper cells are what make both affordable EVs and grid storage possible.
In short
- A battery is thousands of lithium-ion cells; the decisive number is cost per kilowatt-hour, so Tesla obsesses over the cell and the factory.
- The 4680 is a larger "tabless" cell — shorter internal path, less heat, faster charging, fewer cells per pack — aimed at lower cost at scale.
- The same cells scale up into the Megapack, a utility battery that stores renewable power; with Autobidder it became a fast-growing, high-margin business.
The lithium-ion cell
A lithium-ion cell stores energy by shuttling lithium ions between two electrodes through a liquid electrolyte; charging pushes them one way, discharging lets them flow back and drive a circuit. An electric car or a grid battery is really just thousands of these cells packaged, cooled and managed together. The whole economics of electrification comes down to one number — the cost per kilowatt-hour of those cells — which is why Tesla obsesses over cell design and, even more, over the machine that builds the cell.
The 4680 cell
Tesla's 4680 cell (46 mm wide, 80 mm tall) is a larger format designed to cut cost and simplify manufacturing. Its "tabless" design shortens the electrical path inside the cell, which reduces heat and allows faster charging and discharging, and the larger size means fewer cells and less packaging for a given pack. Bigger cells plus simpler assembly is a bet on driving down cost per kilowatt-hour at scale — the same logic that drove the original Gigafactory concept.
From cars to the grid: Megapack
The same cell technology scales up into stationary storage. The Megapack is a large, pre-assembled utility battery — each unit stores several megawatt-hours — that grid operators install to store cheap or renewable power and release it when demand peaks, stabilising the grid and making solar and wind far more useful. Paired with Tesla's Autobidder software, which automatically trades stored energy on electricity markets, Megapack turned Tesla's energy division into one of its fastest-growing, highest-margin businesses.
Frequently asked
Cite this page
Reviewed Jul 29, 2026ElonFacts.org. (2026). How Tesla’s Batteries and the 4680 Cell Work. Retrieved from https://elonfacts.org/explainers/how-tesla-batteries-work
"How Tesla’s Batteries and the 4680 Cell Work." ElonFacts.org, Jul 29, 2026, https://elonfacts.org/explainers/how-tesla-batteries-work.
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https://elonfacts.org/explainers/how-tesla-batteries-work