D battery size
34.2 × 61.5 mm
1.5 V · Alkaline · Cylindrical · also sold as LR20, R20, MN1300, Mono
About the D
The large cylindrical cell, still used in lanterns, big radios and some medical equipment. A D cell holds around 12,000 mAh against an AA’s 2,500 — the size is the capacity, since the chemistry is identical.
The numbers
| Diameter | 34.2 mm · 1.35 in |
| Height | 61.5 mm · 2.42 in |
| Nominal voltage | 1.5 V |
| Chemistry | Alkaline |
| Other names | LR20, R20, MN1300, Mono |
Other cylindrical sizes
| Cell | Size | Voltage |
|---|---|---|
| AAA | 10.5 × 44.5 mm | 1.5 V |
| AA | 14.5 × 50.5 mm | 1.5 V |
| C | 26.2 × 50 mm | 1.5 V |
| AAAA | 8.3 × 42.5 mm | 1.5 V |
| N | 12 × 30.2 mm | 1.5 V |
| A23 | 10.3 × 28.5 mm | 12 V |
| CR123A | 17 × 34.5 mm | 3 V |
| 18650 | 18 × 65 mm | 3.7 V |
| 21700 | 21 × 70 mm | 3.7 V |
Frequently asked questions
What size is a D battery?
34.2 mm across and 61.5 mm long — 1.35 × 2.42 inches.
What voltage is a D?
1.5 V (Alkaline).
What is another name for a D?
LR20, R20, MN1300, Mono — all the same cell.
Is the D rechargeable?
Not in this chemistry. Alkaline cells of this size are single-use; recharging one is a fire risk rather than a saving.