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9v batteries

Commonly used in smoke alarms and carbon monoxide detectors, 9v batteries are some of the most important batteries that are used in everyday life.

Designed to have a long service life of up to ten years, 9 volt batteries are used in many crucial devices. However, they should always be regularly tested no matter what the service life, especially when used in a smoke alarm.

The most common types of 9v batteries are:

• Alkaline batteries.
• Lithium batteries.
• NiCD batteries.
• NiMH batteries.

Lithium batteries are probably the most popular choice, as they can last up to five times longer than alkaline batteries. However, all 9v batteries need to be handled correctly if they are to achieve maximum performance.

This means you should never dent or otherwise damage the casing, and the battery should always be connected properly.

Similarities to other batteries

All batteries work in generally the same way. A reaction takes place inside the battery, converting chemical energy to electricity. However, 9v batteries have different connectors to other standard batteries, such as:

• AA batteries.
• AAA batteries.
• Watch batteries.
• D batteries.
• N batteries.

This means there is no chance you will be able to use them in devices or chargers that aren't suited to them. As this can potentially damage batteries, this is useful.

What 9v batteries look like

With the rectangular shape and snap connectors, 9v batteries certainly have a distinctive appearance.

There are two connectors on the top of each 9v batteries, a circular connector and one that is either hexagonal or octagonal. Like many other rechargeable batteries, 9v batteries require specialised chargers.

Most of the major battery manufacturers produce 9v batteries, including:

• Duracell batteries.
• Eveready batteries.
• Panasonic batteries.
• Energizer batteries.

Whatever brand you choose, 9v batteries are suitable for devices that need a long-term, reliable power source.