Speaking of 4680 cells, you may feel strange and familiar, 4680 cells were first released by Tesla on September 23, 2020, Tesla Battery Day event, and are planned to be officially put into production in 2022, but the low voltage of 4680 single battery cannot meet the needs of high-power charging and discharging of mobile power supply, and at the same time, the diameter of 46mm is not suitable for applications on handheld devices such as mobile power supply. However, the 4680 battery, in addition to new energy vehicles, is very suitable for outdoor power applications.
Compared with the traditional 18650 battery and 21700, the power of Tesla's 4680 electrodeless battery is 6 times that of the traditional electrodeless battery, and the electrodeless technology also reduces the internal resistance of the battery, reduces the loss of the battery in charge and discharge, which is equivalent to improving the discharge efficiency of the battery, which is 16% higher than the traditional electrode battery The battery life,It also has a stronger fast charging capacity,This time,The charging head network got the 4680 battery cells launched by BYD,According to the existing information, it is impossible to judge whether this BYD4680 battery cell is the same as Tesla4680 with electrodeless lug design,The following charging head network will fully analyze the performance of this battery from charge and discharge、Internal resistance、Temperature test。
As usual, let's take a look at the appearance of this cell first.
BYD 4680 battery cell cylindrical design, using green cell sleeve film color, and the sleeve film color can be adjusted according to requirements to meet the diverse needs of customers.
One side of BYD 4680 battery cell has a code:
Model 4680, capacity 15000mAh" and "+" positive and negative pole identification.
Nominal Capacity: 15000mah@05c；
Nominal voltage: 32v；Nominal energy: 48wh;
AC internal resistance: 8m.
The contact surface of the negative electrode of BYD 4680 battery cell is made of alloy metal and treated by anodizing process, which is durable and anti-corrosion.
The positive contact surface of BYD 4680 battery cell is still made of alloy, with a pressure relief valve and factory code.
Measured with plastic calipers, the cylindrical height of BYD 4680 battery cells is about 80mm.
Measured using plastic calipers, the diameter of BYD 4680 battery cells is about 462mm。
The weight of BYD 4680 battery cells is about 3347g。
Compared to the diameter of a one-dollar coin.
It can be seen that compared with conventional cells such as 18650, BYD 4680 cells are 3-4 times larger.
BYD 4680 battery cells have an obvious sense of weight in the hands of adults.
After looking at the appearance, let's get to the point;The following will be 02c、0.5C rate for charge and discharge test.
The charge test will be 02c、0.5C rate for constant current and constant voltage charging, and the total time consumption is counted.
Draw a line chart with a current of 3000mA, 02C is to charge BYD 4680 cells, and the charging cut-off voltage is 365V, it takes about 5 hours and 15 minutes.
Draw a line chart with a current of 7500mA, 05C is to charge BYD 4680 cells, and the charging cut-off voltage is 365V, it takes about 2 hours and 11 minutes.
Plot the test data as a line chart, 0. in the charging testIt takes 5 hours and 15 minutes to charge 2C to fully charge, 0It takes 2 hours and 11 minutes to fully charge at 5C.
In the discharge test stage, a constant current discharge will be used to calculate the total time consumed, as well as the discharge capacity and energy values.
Draw a line chart with a current of 3000mA, 02C is the discharge of BYD 4680 cells, and the average voltage is 324V, put to the cut-off voltage of 20V, it takes about 5 hours and 12 minutes, the discharge capacity is 15644mAh, and the release energy is 5064wh。
Draw a line chart with a current of 7500mA, 05C is the discharge of BYD 4680 cells, and the average voltage is 318V, put to the cut-off voltage of 20V, it takes about 2 hours and 04 minutes, the release capacity is 15624mAh, and the energy is 4962wh。
Summarizing the test data into **, it can be seen that the battery cell is discharged at two magnifications, and the shortest discharge time is 05C discharge, the discharge time is about 2 hours and 4 minutes. The longest discharge time is 02C discharge, the discharge time is about 5 hours and 12 minutes.
The test data is summarized into a histogram, and 0. can be seen in the discharge testThe 2C discharge energy is 5064wh，0.5c discharge energy 4962wh；The overall gap is not large, and the highest discharge energy is 02C discharge gear, discharge energy up to 5064Wh, both sets of magnifications exceed the nominal energy.
Let's take a look at the difference in the capacity of each gear, and plot the data as a graph, and you can see 0The discharge capacity of the 2C discharge gear is 15644mAh, 0The 5C discharge capacity is 15624mAh.
In the internal resistance test part, the charging head network will use the internal resistance test instrument to test the full power internal resistance and empty power internal resistance respectively.
Summing up the test data to **, you can see that the fully charged internal resistance voltage is 365V, the air resistance voltage is 20V, the nominal internal resistance of BYD 4680 battery cell is 8m.
Draw out the histogram and you can see 3The internal resistance of 65V is 444m with an internal resistance of 449m, neither of which exceeded the nominal internal resistance, and the difference between the two sets of data was small;Outstanding performance.
In the temperature test part, the charging head network will measure the temperature of each charge and discharge rate after 30 minutes.
The BYD 4680 battery cell is 02C rate for 30 minutes, the maximum surface temperature is 272 or so.
The BYD 4680 battery cell is 0Charge at 5C rate for 30 minutes, and the maximum surface temperature is 294 or so.
The BYD 4680 battery cell is 0The discharge was carried out at 2C rate for 30 minutes, and the maximum surface temperature was 287 or so.
The BYD 4680 battery cell is 0Discharge at 5C rate for 30 minutes, and the maximum surface temperature is 317 or so.
This BYD 4680 battery cell, the charging head network is at 02c、0.Tested at 5c magnification, 0The 5C rate charge can be charged in 2 hours and 11 minutes, and 0The 2C rate discharge capacity is 15644mAh, and the discharge energy reaches 5064wh；All exceeded the nominal parameters.
In terms of temperature, the temperature is tested after 30 minutes of charging and discharging at three different rates, and the charging temperature is in the range of 27-30;The discharge temperature is in the range of 28-32, the overall temperature rise is small, and the calorific value control is excellent.
4680 battery is a standard product, after a large number of **, the product quality and delivery time are more competitive than the traditional small-size cylindrical battery. The 4680 battery can also be matched with the housing to simplify the battery holder design, reduce the internal battery fixing parts of the outdoor power station, simplify the housing design, and free up the internal space.