Lithium-ion batteries possess advantages such as high energy density, no memory effect, stable charge and discharge characteristics, and long cycle life. These advantages have led to their widespread use in consumer electronics products such as mobile phones, laptops, digital cameras, electric bicycles, and electric vehicles. As a power source, lithium-ion batteries are crucial, and their lifespan significantly impacts product performance.
Common misconceptions about lithium-ion battery charging:
I. How to charge a newly purchased lithium-ion battery charger
There have always been various opinions regarding the charging methods for new lithium-ion battery chargers. The most widely circulated claim is that the first charge should last 18 hours to activate the charger. However, this is incorrect. This idea originally referred to nickel-cadmium battery chargers, but we've overlooked the significant differences between lithium-ion and nickel-cadmium battery chargers. Therefore, overcharging lithium-ion chargers will only cause immeasurable damage to the charger itself, let alone any supposed battery activation effect!
II. How to use a lithium-ion battery charger correctly
Many people have a misconception about how to use lithium-ion battery chargers: that deep charging and shallow discharging have a huge impact on the charger's lifespan. Scientific research shows that lithium-ion batteries have a lifespan of nearly 500 cycles. Therefore, when we charge the charger to more power, the charger itself will not be greatly damaged. In other words, the charger and the number of charging cycles are not closely related. Other factors such as shallow charging and discharging do not have a negative impact on the charger.
III. How to charge during normal use
There are many opinions on how to charge lithium-ion batteries during normal use. Some people say to use them until they automatically shut down and are completely out of power before charging, while others say to charge them whenever needed. I've been practicing the first approach myself, but I've found it's unnecessary. Why is that? Let's take a look.
Reason 1: The lifespan of a lithium-ion battery is generally 300-500 charging cycles. Assuming a full discharge provides 1Q of power, and disregarding the decrease in capacity after each charging cycle, a lithium-ion battery can supply a total of 300Q-500Q of power. If you charge after using half the battery capacity each time, it can be charged 600-1000 times; if you charge after using one-third of the battery capacity each time, it can be charged 900-1500 times; if you charge randomly, the number of charges is uncertain. In short, the total amount of power that can be replenished is constant at 300Q-500Q. Therefore, the lifespan of a lithium-ion battery is related to the total amount of power it can be charged, but not to the number of charging cycles. Deep discharge/deep charge or shallow discharge/shallow charge have little impact on the lifespan of a lithium-ion battery.
Reason 2: In fact, shallow discharge and shallow charge are more beneficial for lithium batteries. Deep discharge and deep charge are only necessary when the product's power module is calibrating the lithium battery. Therefore, in daily use, there is no need to be bound by the rule of fully discharging before recharging; you can charge it whenever you need it, prioritizing convenience.
IV. Charging under high temperature conditions
We all know that the temperature of a mobile phone's lithium-ion battery will continue to rise if used for a long time. The lithium-ion battery in a mobile phone will self-discharge under high temperatures, which explains why the battery drains faster when the phone is hot. Furthermore, charging the battery under high temperatures will not only fail to achieve the desired effect, but will also reduce the battery's lifespan.
Precautions for charging lithium-ion batteries
① Prevent overheating during charging
If the temperature of a lithium-ion battery exceeds the specified operating temperature (35°C) during charging, the battery capacity will continuously decrease, meaning the power supply time when fully charged will be shortened. This will damage the battery quality and reduce its lifespan.
②Prevent the charging temperature from getting too low
If the battery is charged in a low-temperature environment (below 4°C), the battery capacity will continue to decrease, and it may even fail to charge. However, the situation is different from that in a high-temperature environment. It is not a permanent damage. When the temperature rises to a suitable level, the battery capacity will return to its previous state.
③ Frequently used
Frequent use keeps electrons in a constant state of flux within the lithium-ion battery, which helps extend its lifespan. If you don't use it frequently, remember to complete a full charge cycle for the lithium-ion battery each month, i.e., perform a deep discharge and deep charge once a month.
④ Lithium-ion batteries must be charged with a dedicated lithium-ion battery charger and the instructions must be followed. Otherwise, the battery may be damaged or even dangerous.
⑤ Preventing frequent use of lithium-ion batteries is arguably the most fundamental method. Even if you usually use external power and it seems like you're not using batteries, the aging process of batteries is actually ongoing over time.
