21700 Battery Size and Voltage
21700 = 21.0 mm diameter x 70.0 mm height, 3.7 V Li-ion rechargeable, ~5000 mAh. Used in Tesla Model 3/Y.
Open the interactive Standards & Sizes tool →Key facts
| Diameter x height | 21.0 x 70.0 mm |
|---|---|
| Voltage | 3.7 V nominal |
| Chemistry | Li-ion (NMC/NCA) |
| Capacity | ≈ 5000 mAh |
| Typical use | Tesla Model 3/Y, e-bikes, flashlights |
Frequently asked questions
What is the difference between 21700 and 18650?
21700 (21 x 70 mm, ~5000 mAh) is larger and higher-capacity than 18650 (18 x 65 mm, ~3500 mAh).
What does 21700 mean?
'21' = 21 mm diameter, '70' = 70 mm length, '0' = cylindrical; a 3.7 V Li-ion cell.
Related pages
21700 Battery Size is part of Standards & Sizes on GOAT Lab — a free reference you can use without signing up, and it works offline. Open the tool above for any custom value.
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