Toolman

AAAA battery size

8.3 × 42.5 mm

1.5 V · Alkaline · Cylindrical · also sold as LR61, MN2500, Mini

About the AAAA

Thinner and shorter than an AAA, used in stylus pens, laser pointers and some glucose meters. It is also what is inside a 9V battery: cut one open and you find six of these in series, which is exactly where the nine volts comes from.

The numbers

Diameter8.3 mm · 0.33 in
Height42.5 mm · 1.67 in
Nominal voltage1.5 V
ChemistryAlkaline
Other namesLR61, MN2500, Mini

Other cylindrical sizes

CellSizeVoltage
AAA10.5 × 44.5 mm1.5 V
AA14.5 × 50.5 mm1.5 V
C26.2 × 50 mm1.5 V
D34.2 × 61.5 mm1.5 V
N12 × 30.2 mm1.5 V
A2310.3 × 28.5 mm12 V
CR123A17 × 34.5 mm3 V
1865018 × 65 mm3.7 V
2170021 × 70 mm3.7 V

Frequently asked questions

What size is a AAAA battery?

8.3 mm across and 42.5 mm long — 0.33 × 1.67 inches.

What voltage is a AAAA?

1.5 V (Alkaline).

What is another name for a AAAA?

LR61, MN2500, Mini — all the same cell.

Is the AAAA rechargeable?

Not in this chemistry. Alkaline cells of this size are single-use; recharging one is a fire risk rather than a saving.

All battery sizes · Unit converters