Battery type and how to choose

Batteries that we usually use for flashlights, remote controls, and thermometers come in a variety of types and sizes, including dry cell batteries such as AA and AAA, button cell batteries, and lithium batteries. There are also round, coin-shaped and other types. This article explains each type of battery, from their uses, to their characteristics, standards, and how to select them.

Types of batteries and their features

Manganese dry cell

It is suitable for electric devices that run on small amounts of power, such as clocks, wall clocks, intercoms, flashlights, and penlights. For devices that require large amounts of power such as remote controls, gas stoves, and automatic ignition of oil heaters, they can be used for short periods of time without problems. The voltage will drop with continued use, but it can be restored by putting it on rest. Manganese dry cell batteries come in sizes AAA to AAA and 9V square.

マンガン乾電池

Alkaline battery

They can be used for more than twice as long as manganese dry cell batteries. The voltage does not drop during use, making them suitable for devices that require large amounts of power, such as headphone stereos, portable MDs, portable radios, and powerful searchlights. Battery sizes include AAA-6 and rectangular 9V.

アルカリ乾電池

Button cell batteries, coin cell batteries

A battery that is smaller in height than in diameter is called a button cell or coin cell battery because of its shape. Types of button batteries include silver oxide batteries and alkaline button batteries. Lithium coin cell batteries are coin cell batteries.

How to read button cell battery types and part numbers

Silver oxide batteries are represented by ‘SR’ and alkaline button batteries by ’LR’. To be precise, ‘S’ stands for silver oxide batteries, ‘L’for alkaline batteries, and ‘R’ for the shape of the battery system, i.e., cylindrical.

The dimensions of button batteries are determined by international standards as 41 (outer diameter: 7.9mm, height: 3.6mm), 43 (outer diameter: 11.6mm, height: 4.2mm), and 44 (outer diameter: 11.6mm, height: 5.4 mm).

Silver oxide batteries are used in precision instruments such as wristwatches and electronic thermometers because their voltage remains constant until the end. Alkaline button batteries are a lower-cost version of silver oxide batteries and are interchangeable. They are less expensive and more economical than silver oxide batteries, but their voltage gradually decreases with use. They are widely used in portable game consoles, watches, calculators, pedometers, etc.

ボタン形電池の種類と品番の見方

Features of coin cell batteries and how to read part numbers

Coin-type lithium batteries, represented as ’CR’ have approximately twice the voltage of SR and LR batteries and less self-discharge, making them suitable for long-term use. They are used for memory backup, electronic organizers, keyless entry, etc.

In the case of a four-digit number, such as CR2016, the first two digits represent the outer diameter - 20mm and the last two digits represent the height - 1.6mm.

コイン形電池の特長と品番の見方

Rechargeable batteries (nickel metal hydride batteries and lithium batteries)

Rechargeable batteries, also known as secondary batteries, are batteries that can be reused if recharged. There are various types of rechargeable batteries, but these three types are widely used: nickel-cadmium batteries, nickel-metal hydride batteries, and lithium-ion batteries.

Nickel-cadmium battery

Nickel-cadmium batteries can be recharged approximately 500 times. They provide a stable voltage, and are used in cordless phones and power tools. However, they have the disadvantage that their voltage decreases simply by being left unattended and a possibility that their original charge capacity decreases when they are recharged consecutively. In addition, they must be disposed of when used up, and must be  handled properly because they contain a hazardous substance called cadmium.

Nickel-metal hydride battery (NiMH battery)

It has the same drawbacks as the nickel-cadmium battery, but the drawbacks are much reduced due to daily developments. They have more than twice the capacity of nickel-cadmium batteries.

Lithium-ion battery

It has become the mainstream rechargeable battery in recent years and is used in cell phones and notebook PCs. They have a high discharge voltage of approximately 3.7 V and can be recharged more than 500 times. Although they tended to be used in  larger devices, technological improvements have made them smaller and lighter in weight. They don’t have as many drawbacks found in nickel-cadmium and nickel-metal hydride batteries, but they emit high temperatures when they are in a state of overcharge or over discharge, so a safety circuit is required.

Camera batteries

Nickel metal hydride batteries are recommended for camera batteries in most cases. Digital cameras, for example, use lithium-ion batteries and have their own chargers. Be sure to check the batteries that are appropriate for your camera model.

カメラ用電池

How to choose a good battery

To select a battery, you need to check which electrical equipment will use the battery. First, high-current devices that require a large current include digital cameras and dry-cell shavers. Medium-current devices include portable games and electronic dictionaries. Low-current devices include wall clocks and remote controls.

Alkaline batteries are recommended for use in all electrical equipment. Manganese batteries are recommended for use in wall clocks and remote controls, but may or may not be used in other devices. Nickel metal hydride batteries are recommended for use in wall clocks and remote controls. Lithium batteries are recommended for use in digital cameras and flashlights (LED).

How to prevent and deal with battery leaks

Dry cell batteries such as manganese and alkaline batteries may leak due to deterioration over time or over-discharge when left inside the equipment. To prevent this, it is recommended to remove batteries from the equipment if they will not be used for a long period of time, or place a piece of paper between the battery terminals to prevent them from discharging.

If a battery does leak, remove and dispose of the battery, and thoroughly wipe off any liquid on the equipment with a cotton swab. Leakage may occur if the equipment is left unattended for a long period of time, so be sure to check the condition of the batteries regularly.

To prevent liquid leakage from occurring:

  • Mount them in the correct orientation.
  • Don’t use different types of batteries together (eg alkaline and manganese, rechargeable batteries, etc.) 
  • Don’t use new batteries and old batteries together.
  • Don’t  leave used batteries unattended.
  • Replace batteries for remote controls, clocks, etc. regularly with new ones before they run out.