The battery has a letter near the positive terminal to indicate the battery number. The comparison is as follows: battery No. 1 is D, battery No. 2 is C, battery No. 3 is A, battery No. 5 is AA, and battery No. 7 is AAA. Please refer to the picture below for the specific location.

The D model is the No. 1 battery, which is widely used in civilian and military applications. It is the same as the ignition setting flashlight. The standard D (flat head) battery has a height of 59.0±0.5mm and a diameter of 32.3±0.2mm.

C model: No. 2 battery, commonly used in flashlights and audio-visual equipment. The standard dimensions are battery height 49.5±0.5mm and diameter 25.3±0.2mm.

Type A battery is AA battery, generally used as a battery pack. The height of Type A battery is similar to that of AA battery, but the diameter is slightly smaller. The standard A (flat head) battery has a height of 49.0±0.5mm and a diameter of 16.8±0.2mm.

AA-type batteries are AA batteries, which are the most common. They are most commonly used in electric shavers, electronic toys, digital devices, etc. Many AA-type rechargeable batteries are also used as battery packs.

AAA size batteries are commonly known as AAA batteries, as shown in the picture below. AAA batteries are slightly smaller than AAA batteries. They are mostly used in remote controls and other situations where the size is limited but the power consumption is not too large. Most of them are used in combination with multiple sections.

Extended information:

Battery purchase

1. Purchase battery products with the "National Inspection-Free" and "Chinese Famous Brand" logos and local famous brand batteries products, the quality of these products is guaranteed.

2. According to the requirements of the electrical appliance, select the applicable battery type and size, and purchase the battery suitable for the electrical appliance according to the size and characteristics of the electrical appliance's power consumption.

3. Pay attention to the production date and shelf life of the battery, and buy batteries (new batteries). New batteries have good performance.

4. Pay attention to the appearance of the battery. You should choose a battery with exquisite packaging, neat and clean appearance, and no signs of leakage.

5. Pay attention to the logo of the battery. The battery trademark should indicate the name of the manufacturer, battery polarity, battery model, nominal voltage, trademark, etc.; the sales package should have the Chinese factory address, production date and shelf life or Indicate the expiration date of the shelf life and the number of the implementation standard. Do not buy products that do not have a Chinese factory name, a production date and a shelf life, or a shelf life expiration date, or a product that has no implementation standards.

6. Since mercury in batteries is harmful to the environment, in order to protect the environment, you should choose batteries with the words "mercury-free", "0 mercury" and "no added mercury" on the trademark when purchasing.

Baidu Encyclopedia-Battery