# Battery

A battery provides power to electrical devices. Batteries have to terminals: a positive cathode and a negative anode. When the battery is connected in a complete circuit, the electrons will flow from to negative terminal to the positive terminal, and the current will flow from the cathode to the anode.

Electronic symbol for battery.

### Battery discharge time

Battery discharge rate

The life of a battery can be calculated by dividing the capacity by the discharge rate.

t is the symbol for time and is measured in seconds (s).
C is the symbol for capacity and is measured in ampere-hour (Ah).
I is the symbol for current and is measured in ampere (A).

### Battery types

Battery types

Batteries come in many different shapes and sizes. You can find the common ones in the table below.

name typical capacity (mAh) nominal voltage size diameter x height (mm)
4/5 AA 600-1500 1.2 14 x 40
½ AA 850-1200 3 14 x 25
AAAA 625 1.5 8.3 x 42.5
AAA 1200 1.5 10.5 x 42.5
AA 2700 1.5 10.5 x 44.5
A 1.5 14.5 x 50.5
B 8350 1.5 17 x 50
C 8000 1.5 21.5 x 60
Sub-C 1200-2400 1.2 26.2 x 50
D 1200 1.5 22.2 x 42.9
F 26000 1.5 34.2 x 61.5
N 800-1000 1.5 33 x 91
A23 55 12 12 x 30.2
A27 22 12 10.3 x 28.5
BA5800 7500 5.3 8 x 28.5
Duplex 3 21.8 x 74.6
4SR44 110-150 6.2 13 x 25.2
Rectangular H x L x W
4.5-Volt 6100 4.5 67 x 62 x 22
9-Volt / E 565 9 48.5 x 26.5 x 17.5
6-Volt Lantern 26000 6 115 x 68.2 x 68.2
Lantern (screw) 10500 6 109.5 x 66.7 x 66.7
Lantern (Big) 22000 6 125.4 x 132.5 x 73
J 625 6 48.5 x 35.6 x 9.18