Cell technology · An engineering primer
Inside the cell.
Every Tesla battery is a few thousand, a few hundred or about a hundred cells wired together. Their shape and chemistry decide much of what a pack can do. Here they are to scale, with plain explanations for owners and enough depth for engineers.
Hover or tap a cell to inspect it. Cylinders are drawn from their nominal dimensions. Prismatic and Blade shapes are schematic because Tesla-specific dimensions are unpublished.
4680
Cylindrical · Ø46 × 80 mm · tabless
Tesla's own large-format cell, unveiled at Battery Day 2020.
Explore 4680 packs- First used
- 2022
- Packs
- 3
- Vol. vs 18650
- 8.04×
Cylindrical vs prismatic
Cylindrical cells wind long electrode sheets into a tight spiral (the 'jelly roll') inside a steel can. Prismatic cells stack or fold flat electrodes inside a rectangular case. Cylinders are mass-produced, mechanically robust and easy to cool from the side; prismatic cells pack more tightly with fewer parts per kWh.
| Format | Diameter | Height | Volume | vs 18650 | First Tesla use |
|---|---|---|---|---|---|
| 18650 | 18 mm | 65 mm | 16.5 cm³ | 1.00× | 2008 · Roadster |
| 2170 | 21 mm | 70 mm | 24.2 cm³ | 1.47× | 2017 · Model 3 |
| 4680 | 46 mm | 80 mm | 133 cm³ | 8.04× | 2022 · Model Y (Austin) |
| Prismatic LFP (CATL) | Tesla-specific dimensions not published | — | 2020 · Model 3 (Shanghai) | ||
| Blade (BYD) | Tesla-specific dimensions not published | — | 2023 · Model Y (Berlin) | ||
Volumes are calculated by Tesla Battery Atlas from nominal dimensions (π·r²·h) and are estimates. Tesla attributed part of the 4680's range gain to the form factor alone at Battery Day 2020. Source ↗
Cross-sections
Larger cylinders mean fewer cells, welds and connections per kWh. The tabless 4680 conducts current along the whole electrode edge, which shortens the electrical path and helps manage heat in a big cell.
NCA vs NMC vs LFP
The cathode material sets the trade between energy, cost, longevity and safety margin. These are general characteristics of each chemistry family. Individual cells vary, and newer generations narrow the gaps.
| General characteristic | NCA | NMC | LFP |
|---|---|---|---|
| Cathode | Nickel, cobalt, aluminium oxide | Nickel, manganese, cobalt oxide | Lithium iron phosphate |
| Energy density | High | High | Lower |
| Cobalt | Small amount | Varies with nickel ratio | None |
| Daily charge habit | Usually limited below 100% for daily use | Usually limited below 100% for daily use | Tolerates regular charging to 100% |
| Cold weather | Less affected | Less affected | More sensitive; preconditioning matters |
| Thermal stability | Good with management | Good with management | Very high |
| Typical Tesla use | Panasonic packs: Model S/X, Fremont Model 3/Y | LG packs (Shanghai, Berlin), 4680 | Rear-wheel-drive Model 3 and Model Y |
| Packs in this database | 85907510031C3L1L | 5C5L4680 MY5M5N8L | 6C6L7C6M |
Charging guidance comes from Tesla's own in-car recommendations, which differ by chemistry. Always follow the guidance shown in your vehicle.
Structural vs non-structural packs
A conventional pack is a sealed box bolted under the floor: the body carries the loads and the pack carries the cells. In a structural pack, the pack itself becomes part of the body, often forming the cabin floor, which removes parts and stiffens the car.
Cell density isn't pack density
Gravimetric energy density (Wh/kg) measures energy per unit of weight. It falls from cell to pack, because enclosures, cooling, wiring and electronics add mass. A pack-level figure is the honest number for a car, but it is rarely published.
EPA data shows the refreshed Model X pack reaching about 186 Wh/kg at pack level, up from about 165 Wh/kg, with roughly the same energy. Source ↗
Pack-level energy density in this database
Documented values are solid; values calculated from capacity ÷ mass are dashed and marked ≈.
- LG 5N≈190 Wh/kg
- LG 5M≈189 Wh/kg
- Model S/X 2021+186 Wh/kg
- LG 5L≈173 Wh/kg
- Model S/X 100165 Wh/kg
- Roadster ESS≈118 Wh/kg
Charging, durability and heat
Charging performance
Peak DC power is only part of the story. How long a pack holds high power depends on state of charge, cell temperature and chemistry. Packs charge fastest when warm and relatively empty, then taper as they fill. A larger pack can absorb more power at the same cell-level stress.
Tesla's Cybertruck moves to an 800 V architecture; Model 3 and Model Y packs remain 400 V-class.
Durability
Cells age with time (calendar aging) and with use (cycle aging). Heat and long periods at very high or very low states of charge speed both up. LFP chemistry generally tolerates full charges well, which is why LFP Teslas can be charged to 100% routinely.
Capacity readings vary with temperature and calibration. Compare like with like over time.
Thermal management
Tesla packs are liquid-cooled and liquid-heated. Preconditioning warms the pack before fast charging. It matters most for LFP packs in cold weather: independent testing of the BYD-equipped Model Y found fast charging depends heavily on it.
Navigate to a Supercharger to trigger automatic preconditioning.
General explanations reflect widely published battery engineering principles. Pack-specific claims link to their sources on each battery page. How we source data. Dataset: 22 packs.