Milliampere-hours (mAh) is a unit of measurement that indicates the capacity of a battery. It is used to measure the amount of energy a battery can store and the amount of time it can supply power to a device. In the context of RC cars, the mAh rating of a battery is an important factor to consider when choosing the right battery for your car.

A higher mAh rating means that the battery has a higher capacity to store energy and can therefore power your RC car for longer periods of time before needing to be recharged. For example, a battery with a mAh rating of 2000 will have a longer runtime than a battery with a mAh rating of 1000. This is especially important if you plan on using your RC car for long periods of time or for racing.

It's also important to note that a higher mAh rating does not necessarily mean that a battery is better. A higher mAh rating usually means that the battery is physically larger and heavier, which can affect the performance and handling of your RC car. Therefore, it's important to find a balance between the mAh rating and the physical size and weight of the battery to ensure that it is compatible with your RC car and meets your needs.

In addition to the mAh rating, other factors such as the voltage, chemistry, and discharge rate of the battery are also important to consider when choosing the right battery for your RC car. It is always recommended to check the manufacturer's recommendations for the appropriate battery for your specific RC car model.