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# UnitElectricCharge

A unit of measure for electric charge.

```
class UnitElectricCharge
```

## Overview

You typically use instances of [`UnitElectricCharge`](/documentation/Foundation/UnitElectricCharge) to represent specific quantities of electric charge using the [`NSMeasurement`](/documentation/Foundation/NSMeasurement) class.

### Electric Charge

Electric charge is a fundamental physical property of matter that causes it to experience a force within an electromagnetic field. The SI unit for electric charge is the coulomb (C), which is defined as the amount of charge carried by a current of one ampere in one second (1C = 1A · 1s). Charge is also commonly expressed in terms of ampere hours (Ah).

The [`UnitElectricCharge`](/documentation/Foundation/UnitElectricCharge) class defines its [`baseUnit()`](/documentation/Foundation/Dimension/baseUnit()) as [`coulombs`](/documentation/Foundation/UnitElectricCharge/coulombs), and provides the following units, which are initialized using [`UnitConverterLinear`](/documentation/Foundation/UnitConverterLinear) converters with the specified coefficients:

|Name             |Method                                                                                     |Symbol|Coefficient|
|-----------------|-------------------------------------------------------------------------------------------|------|-----------|
|Coulombs         |``doc://com.apple.foundation/documentation/Foundation/UnitElectricCharge/coulombs``        |C     |`1.0`      |
|Megaampere Hours |``doc://com.apple.foundation/documentation/Foundation/UnitElectricCharge/megaampereHours`` |MAh   |`3.6e9`    |
|Kiloampere Hours |``doc://com.apple.foundation/documentation/Foundation/UnitElectricCharge/kiloampereHours`` |kAh   |`3600000.0`|
|Ampere Hours     |``doc://com.apple.foundation/documentation/Foundation/UnitElectricCharge/ampereHours``     |Ah    |`3600.0`   |
|Milliampere Hours|``doc://com.apple.foundation/documentation/Foundation/UnitElectricCharge/milliampereHours``|mAh   |`3.6`      |
|Microampere Hours|``doc://com.apple.foundation/documentation/Foundation/UnitElectricCharge/microampereHours``|µAh   |`0.0036`   |

## Topics

### Accessing the Base Unit

[`baseUnit()`](/documentation/Foundation/Dimension/baseUnit())

Returns the base unit.

### Accessing Predefined Units

[`coulombs`](/documentation/Foundation/UnitElectricCharge/coulombs)

The coulombs unit of electric charge.

[`megaampereHours`](/documentation/Foundation/UnitElectricCharge/megaampereHours)

The megaampere hours unit of electric charge.

[`kiloampereHours`](/documentation/Foundation/UnitElectricCharge/kiloampereHours)

The kiloampere hours unit of electric charge.

[`ampereHours`](/documentation/Foundation/UnitElectricCharge/ampereHours)

The ampere hours unit of electric charge.

[`milliampereHours`](/documentation/Foundation/UnitElectricCharge/milliampereHours)

The milliampere hours unit of electric charge.

[`microampereHours`](/documentation/Foundation/UnitElectricCharge/microampereHours)

The microampere hours unit of electric charge.


---

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