Replenishment charging is no problem Surprising new common sense of battery ｜ NIKKEI

Smartphones that many people carry every day. If you're a business person, you probably have a laptop or tablet in your bag. When using these terminals outdoors, the problem is the battery. If power is wasted, it may not be available at the crucial time. To prevent the battery from running out, it is important to know the characteristics of the battery and use it wisely. Therefore, let's learn the basics of batteries and new common sense.

Q1 Why does the battery run out?

As the battery is repeatedly charged and discharged, the capacity that can be charged naturally decreases. This is unavoidable due to the characteristics of the battery. When I checked the notebook computer "Let's Note RZ4" that I bought about three and a half years ago, it was initially usable up to 36,020 mWh, but now it has decreased to 27,470 mWh. It is 24% worse than when it was shipped from the factory.

The main cause of deterioration is internal chemical changes. Inside the rechargeable battery, there are positive and negative poles, and lithium ions move between them to charge and discharge. However, if it is used for a long time, a thin film will be formed on the positive pole, making it difficult for ions to pass through, and the performance of the battery will deteriorate.

Q2 How long is the battery life?

Generally, it is said that the battery life is less than half of the maximum capacity at the time of shipment from the factory. So how long will it be less than half? This also depends on the performance of the battery, but most manufacturers set a guideline of about 300 to 500 times (recently, there are some that can be used 600 to 800 times due to improvements that slow down deterioration).

The number of charges is counted as one charge with 0 to 100% charge. In the case of replenishment charging, a total of 100% charge is enough for one charge. The number of times of charging is counted as one charge when 100% of the charge is charged, such as 0 to 100%. Also, when the battery is recharged with 60% and 40%, the total is 100%, which is one dose. You can check the number of times of charging by using the software attached to the manufacturer.

You can check the number of charges using the software attached to the manufacturer.

Q3 Have you heard that recharge is not good?

It is a past story that the battery must be charged after it is used up. The reason why it was said that recharge was not good was because there was a deterioration phenomenon called "memory effect". However, this is a story about NiCd rechargeable batteries and NiMH rechargeable batteries. Currently, the mainstream lithium-ion rechargeable batteries do not have a memory effect, so it is okay to recharge them.

Instead, avoid only "0%" and "100%" states.