Output voltage and application of button battery

Button battery is small and easy to use, and is the main power supply or backup power supply for micro electronic products in the consumer, industrial and medical fields. Driven by the Internet of Things, button batteries are used more and more widely. For example, computer motherboards, wireless sensing networks, smoke alarms, portable medical devices, data acquisition terminals, electronic toys, remote controls, car keys, computer peripherals and portable audio devices.

Although the button battery is small in shape, its thickness and output voltage are different. Today's Internet of Things applications require longer battery life, which makes MCU and other digital circuits face three challenges in application design: battery life, cost and volume. This requires engineers to choose different battery types according to applications.

There are many kinds of button batteries, most of which are named after the materials used, such as silver oxide batteries, button batteries, alkaline manganese batteries, etc. According to the charging type, there are two types: non rechargeable battery and rechargeable battery, and the output voltage is the most important parameter in application.

Non rechargeable button batteries include: 3V lithium manganese battery (CR) series, 1.5V alkaline button battery (LR series, including Ag series), 1.55V zinc silver oxide battery button battery (SR) series, and less used 1.4V zinc air battery (ZA series) and 1.35V mercury battery.

Rechargeable button batteries include 3.6V lithium ion button batteries (LIR series) and 3V lithium ion button batteries (ML and VL series).

At present, the most commonly used button batteries are CR series and Ag series.

CR series are 3V lithium manganese button batteries, such as CR2032, CR2025, etc. The nominal voltage is 3V, the termination voltage is 2V, and the typical working current is 0.1-0.2mA. The characteristics of this button battery voltage and current make it more used in electronic dictionaries, mainboard CMOS, watches and other electronic products.

The Ag series consists of 14 Ag0-Ag13 products, belonging to the LR series of alkaline button batteries, with a voltage of 1.5V. It is suitable for the discharge requirements of microamps and is mainly used in calculators, electronic toys, hearing aids and watches.

Among the non rechargeable button batteries, the zinc silver oxide battery has played a very important role. The zinc silver oxide battery, represented by SR, has the advantages of large capacity, stable discharge voltage, good storage performance, etc. The battery voltage is 1.55V, and the high-order discharge curve is stable. About 90% of the batteries are always stable above 1.45V, and the discharge curve is almost a straight line. The battery can be designed to the same size as the alkaline button battery.

LIR series rechargeable button battery is the button battery with the highest voltage of a single battery. Its working voltage is up to 3.6V, which is three times that of the nickel metal hydride battery of the same model, while ML series and LV series rechargeable button batteries are 3V. The difference between LIR series and LIR series lies in the applicable voltage. The rechargeable button battery is applicable to all kinds of electronic products.

For applications with voltages above 3V or even higher, it is necessary to stack multiple button batteries into different voltage battery packs (battery packs) for use, for example, 6V F22, 11A, 26A, 476A, 9V 6F22, 10A, 25A, 8.4V 120H7D, 12V 23A, 27A, etc.

In most battery powered applications, engineers should not only select appropriate battery models, but also make efforts in circuit design, such as using efficient Boost boost DC-DC converters, or even Buck boost converters