A 9V – or Nine-volt – battery is recognizable by its rounded rectangular shape rather than the cylindrical design of other common standard batteries (think AA/AAA/ C/ D, for example). 9V batteries are commonly made of six individual cells that are then enclosed in a singular wrapper to form a block and are available in several chemistry types, with standard 9V batteries typically being either carbon-zinc and alkaline or lithium-iron disulphide batteries.Typically, a 9V battery is capable of providing the equivalent to six AA cells, however the compact nature of a 9V battery may make it more practical than using multiple smaller cells. This is especially true for applications that span a long time, such as smoke detectors.Our range of 9V batteries includes products from well-known brands, such as Duracell, Energizer, Ansmann, Panasonic, RS PRO and Varta, among others. If you are looking for rechargeable 9V batteries, please view our range here.What are 9V batteries used for?These batteries are particularly useful in long-life applications that require a lot of power due to their high energy capacity. Their applications vary, but they can found in a wide variety of industries, from medical to security.9V batteries were originally developed for transistor radios, but can still be found today in handheld versions along with other handheld devices, such as test and instrumentation devices, especially those with backlit LCD displays.Due to their long performance life, 9V batteries are also used in applications that may remain dormant for some time, often in extreme environmental conditions which their moisture-resistant wrappers protect them from. This may include safety devices such as security sensors, smoke alarms and detectors, emergency beacons and monitoring devices.A long performance life also means the battery should be changed at a lower frequency than smaller cells, making them ideal for environments where hygiene is incredibly important. This is why 9V batteries can often be found in medical devices and equipment, such as surgical lighting, data recorders, some patient monitors and even some medical instrumentation.