D battery reference
A D battery is a 1.5V cylindrical alkaline cell 34.2mm in diameter and 61.5mm long — the largest standard consumer cell.
Exact specs
| Designation | D (IEC: LR20, ANSI: 13A) |
|---|---|
| Diameter | 34.2 mm |
| Length | 61.5 mm |
| Nominal voltage | 1.5V |
| Typical capacity | 12,000–18,000 mAh |
| Chemistry options | Alkaline, NiMH rechargeable (1.2V) |
What devices commonly use it
Large flashlights, boomboxes, camping lanterns, and high-drain devices that need long runtime typically use D cells.
What it's interchangeable with
NiMH rechargeable D cells are drop-in substitutes with 1.2V nominal. Lithium D cells exist but are uncommon.
What it's NOT interchangeable with
D cells cannot be substituted by C, AA, or any smaller alkaline format because diameter is significantly larger.
Common mistakes
- Assuming D and C are identical because both are "big" batteries.
- Inserting D cells upside down in spring-loaded trays.