Although the question is several years old, the person who answered it last time was left speechless. .
From the figure, the retention rate increases every 10 times, which may be because the discharge current is lower than the other 9 times. The retention rate is only about 75% after about 100 times, which indicates that the material ratio may not have reached market demand. For those who don't know much about batteries, don't worry, your battery will be so liquid. At least your cell phone can be used for at least a year, right?
General lithium batteries currently on the market can achieve a capacity retention rate of 80% at a discharge rate of 1C. The development direction of the battery industry is to have higher and higher capacities, thinner and higher batteries. possible retention rate. Betterx and better.
Because it is not easy to know 100% the remaining power of a lithium battery. Simply put, the voltage of a lithium battery when discharging is not linear, but a curve, and. it is also likely to be affected by environmental and other factors, different individual batteries also have slight differences. Additionally, usage time also affects the battery. Battery performance will decrease over time and the battery discharge curve will also change after a certain period of use. The 1% displayed on your phone battery may not be the real 1%. In general, there are many parameters that affect the battery, and it is not easy to measure them without errors. The remaining power of a lithium battery is estimated via the components, but what is actually decreasing is the battery voltage. This value isdifficult to determine precisely.
Let's take a look at the discharge curve. The vertical axis is voltage and the horizontal axis is electricity discharged. The discharge current also affects the voltage. The different colored lines in the figure correspond to the discharge current. The higher the current, the faster the voltage drops. It is fired based on constant current discharge. In actual use, the current of the mobile phone varies greatly when it is in different states such as sleep, calling, running applications, games, etc.
However, battery capacity will age with use, but the degree of aging is difficult to estimate. The temperature will also affect the battery, causing the discharged power and lithium battery to decrease. self-discharges, and it will also discharge slowly. During production, the batteries are presentThere will also be slight differences, resulting in different aging and discharge curves. Therefore, battery manufacturers do not recommend mixing batteries from different batches.
At the same time, since the lithium battery will cause irreversible damage to the battery once completely discharged, most manufacturers will not mark the completely exhausted battery as 0% when discharging. nominal capacity calibration. The user sees 1%. This is actually an estimated value that combines various factors and reserves some buffer time to remind the user to charge on time, so it will give the illusion that "the last 1% of the battery is very sustainable ". .