# 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 |