A 9-volt battery is a small, rectangular-shaped battery typically used in portable electronic devices such as smoke detectors, remote controls, and guitar pedals. It has a nominal voltage of 9 volts and is typically composed of six cylindrical or rectangular cells connected in series. The cells are usually either alkaline or carbon-zinc.

The battery connector is the component that connects the battery to the device it powers. In the case of a 9-volt battery, the connector is usually a snap-on clip that fits onto the battery’s terminals. The connector typically has two wires, one positive and one negative, that run from the clip to the device’s circuitry. The positive wire is usually red and the negative wire is usually black. The connector is designed to be easy to attach and detach, allowing the battery to be replaced easily when it runs out of power.

The 9-volt battery and battery connector have a wide range of applications in portable electronic devices that require a relatively low amount of power.

Smoke detectors: Many residential and commercial smoke detectors use 9-volt batteries as a backup power source in case of a power outage.
Remote controls: Many TV remote controls and other household appliances are powered by 9-volt batteries.
Toys: Many battery-operated toys, such as remote-controlled cars and robots, use 9-volt batteries to power the device.
In addition to the above applications, the battery connector is used in a variety of other electronic devices that require portable power. These connectors allow for easy battery replacement and help ensure a reliable connection between the battery and the device.