Contributed commentary by Michele Windsor, Global Marketing Manager, Ultralife Corp.
The 9 V battery was originally invented for transistor radios in the 1950s and, at the time, it was actually expected to deliver 22.5 V. As the power demands of transistor radios came down, so did the power output of the battery, until its size and power was eventually standardized into the 1604 international ANSI standards.
Today, the 9 V battery is used in everything from speakers and smoke alarms to walkie-talkies and industrial meters. Despite this change of scene, most 9 V batteries simply aren’t built to handle the wide and diverse applications they are now used in. Let’s take a look at three areas in particular and what engineers should consider before choosing the right 9 V battery.
Even though electronic devices have become much smaller in the last few years, they’ve also been packed with a growing list of features. Handheld radios, test, and instrumentation devices, portable speakers, and wearable devices, for example, often feature backlit LCD displays, radio antennas for cellular GSM, CDMA, or WiFi communication and powerful speaker drivers, as well as a whole host of sensors.
When choosing a battery for handheld devices you must consider three things: size, weight, and energy density. Size and weight go without saying. After all, you don’t want to design a product that is bigger than necessary just to accommodate the battery. What most people forget, however, is that as you make the battery smaller youre also reducing the runtime. To compensate, choose a battery with a higher energy density so that it will offer the same runtime as a bigger battery.
According to the US National Fire Protection Association (NFPA), dead batteries caused 24 percent of all smoke alarm failures in 2015. As the sole purpose of a smoke alarm is to alert the user of a fire, it is absolutely critical that the battery performs.
Similarly, safety devices such as security sensors, emergency beacons, telematics, and metering devices usually lie dormant for long periods of time, often in extreme environments, only calling on their batteries infrequently.
For safety and security applications, consider a battery with a long storage life and a wide temperature range. For example, Ultralife’s U9VLJP lithium-manganese dioxide 9 V battery has been shown to offer a shelf life in excess of ten years with little loss in performance. The battery can also be used in temperatures from -40C to 60C.
Probably the biggest challenge for the 9 V battery is in medical applications. Devices in medical and healthcare environments usually see more frequent use and the equipment is usually more sensitive to electromagnetic interference (EMI). Devices typically range from medical instruments and patient monitors, to data recorders and surgical lighting.
When choosing a 9 V battery for medical use, consider a high pulse capability and a non-magnetic design. A high pulse rate will deliver consistent power to even the most demanding devices, something that has been achieved in a 9 V battery by designing it with low internal impedance so that it can supply a high power output with a stable voltage.
Taking these small steps in choosing a 9 V battery will result in significantly better long term performance suited precisely to each sector’s needs, so that we can stop replacing our batteries out of habit, but rather because we actually need to.
For more information visit Ultralife Corp.