Cylindrical Batteries reference
18650
Battery equivalent chart, replacements, and specs
18650 aliases and equivalent names
Common search labels and closely related markings include 18650B, ICR18650. Packaging conventions vary, so confirm the compatibility grade, voltage, chemistry, and dimensions shown below before replacing the battery.
Voltage
3.7 V
Chemistry
LiIon
Capacity
2500–3500 mAh
Size
18×65 mm
1865018 × 65 mm
Do not use
Not Compatible- 20700 — Larger diameter — not interchangeable
- 21700 — Tesla/Panasonic EV format — different size
Technical data
Specifications
| Specification | Value |
|---|---|
| IEC / Common Code | 18650 |
| Chemistry | LiIon |
| Nominal Voltage | 3.7 V |
| Capacity | 2500–3500 mAh |
| Cutoff Voltage | ~2.5 V |
| Dimensions (D × H) | 18 × 65 mm |
Typical applications
- Laptop battery packs
- Flashlights
- Power banks
- Vape devices
- DIY energy storage
Applications
Side-by-side comparisons
Frequently Asked Questions
Is 18650 the same as AA?
No. 18650 is 3.7V lithium-ion and physically larger than AA alkaline cells.
Should I always trust cross-reference charts?
Confirm replacements with your device manual — especially for lithium vs alkaline chemistries.
Related Batteries
Review record and primary sources
Reviewed by PlainBattery Technical Review Desk on 2026-08-25. Checked: model and alias mapping, nominal voltage and chemistry, physical dimensions, capacity range and replacement warnings.
- US18650VTC6 Product Datasheet — Murata Manufacturing, 001. Representative 18650 dimensions, charge limits, capacity and discharge characteristics.
Revision record: source citations and field-level review scope added September 11, 2026. See our sources and methodology and corrections policy.
Selection notes
Only buy name-brand cells with verified capacity. Avoid counterfeits — use protected cells in series packs.
Last verified Aug 25, 2026. Always confirm voltage, chemistry, and dimensions with the device manufacturer before replacing any battery.