Check the new battery technology breakthrough in BYD DENZA N7 car.This N7 car BYD uses CTB technology.
1.Denza N7 car CTB introduction
As an intelligent luxury hunting SUV, Denza N7 has launched a total of 6 models. Using the latest CTB technology, its volume utilization rate has increased to an astonishing 77% (you must know that Kirin Battery claims to have the highest volume utilization rate of 72%). The total energy package reaches 91.392kWh, which can meet the cruising range of more than 700km for the long-range version and 630km for the four-wheel drive version. In everyone’s impression, the power of LFP batteries in the passenger car field has increased from about 40~50kWh in 2019 to about 60kWh in Tesla Model 3; and then increased to about 77kWh in BYD Han EV through blade battery technology. With the introduction of CTB technology and the upgrade of battery core materials, Seal has further increased the charge capacity to 82.56kWh. This time, relying on ultra-high volume utilization, Denza N7’s LFP blade battery has a charge capacity of 91.392kWh. In Seal, An increase of more than 10% based on the
2.Battery technology for electric vehicles Denza N7
Although Denza N7 has launched 6 models, the battery power is 91.392kWh. Due to the adoption of BYD’s latest CTB technology, its volume utilization rate is as high as 77%.
Seal’s battery cells are divided into four partitions by cross beams and longitudinal beams. This is different from the Han EV with CTP technology. The latter does not have longitudinal beams, but uses the battery cells themselves as beam structural members.
Seal is divided into two energy versions, the one with a range of 550km is 61.44kWh, and the one with a long range of 700km is 82.56kWh. It is worth mentioning that the battery pack outer envelope of these two models is the same, only the low-end model has an expansion space, its battery cell capacity is 150Ah, which is an upgrade from the original 135Ah battery cell, with a size of approximately 9609013.5mm; the number of strings of battery cells determines the charge capacity of the battery pack: the low configuration is 128 strings, and the high configuration is 128 strings 172 strings (for comparison, BYD Han EV has 178 strings and a total energy of 85.44kWh).
Denza N7 has a charged capacity of 91.392kWh, which is about 11% higher than Seal’s 82.56kWh. If the same battery core is used, the number of strings will increase from the current 172 to 1721.11=190 strings, and its total energy will be 190 3.2V150Ah=91.2kWh. Analyzing whether it can accommodate 190 batteries in terms of body size, the length, width and height of Denza N7 are 48601935*1602mm, and the wheelbase is 2940mm.
The length, width and height of Seal are 4800 x 1875 x 1460mm, and the wheelbase is 2920mm. The length and wheelbase have not increased much, but the width has increased by 60mm. Considering that the thickness of the battery core is about 13.5mm, 8 more batteries can be accommodated. Battery cells (180<190) are more difficult to arrange. Taking into account the volume utilization rate of 77%, maybe the N7 cancels the crossbeams and longitudinal beams. Since its wheelbase and width are relatively close to those of the Han EV, it can adopt a layout similar to the Han EV. Even so, it will only be 178 strings at most. 190 strings is still a long way off.
In addition to benchmarking Seal and Han EV, since Denza N7 is a hunting SUV, its body height of 1602mm is 142mm higher than Seal’s 1460mm. If the battery cell height can be upgraded, its charge capacity will also be greatly improved. . For example, although the 2022 Tang EV has a wheelbase of only 2820mm, its body height reaches 1725mm, so it uses a 96013.5102mm battery cell. Since the height has increased by about 11.3% from 90, the capacity has been upgraded from 150Ah to 170Ah. If Denza N7 uses 170Ah batteries, to achieve 91.392kWh, the number of strings is 168. Considering that Seal has achieved 172 strings with a width of 1875mm, it should be relatively easy to achieve 168 strings for the Denza N7 with a width of 1935mm.
Coincidentally, 1683.2V170Ah=91.392kWh is exactly the same as the official value. It is very likely that Denza N7 uses the same 170Ah blade battery as Tang EV. On the other hand, the D9 pure electric version of Denza Motors has a charged capacity of 103.36kWh, uses a 170Ah battery cell, a rated voltage of 608V (obtained from the nameplate information), and the number of strings is 608/3.2=190 strings.
Since the D9 is an MPV model with a longer body length, it can achieve 190 rows. Two cars of the same brand use the same battery cells, which also facilitates cost reduction. This also confirms the speculation that the N7 uses 170Ah blade batteries.
3.lifepo4 battery kwh on EV sum
Although the LFP blade battery of Denza N7 has exceeded 90kWh, the maximum charge capacity of the LFP battery is still “other than that of another car”, which is the 2022 BYD Tang EV. There are two versions. The low-end version has a charge capacity of 90.3kWh, and the high-end version has a charge capacity of 108.8kWh, which has exceeded 100kWh.
You must know that before the emergence of CATL Qilin batteries, many models with high specific energy ternary batteries (single energy density 250Wh/kg) only had a charge of 100kWh (such as ZEEKR 001 and NIO ES6, both of which are CATL Custom-developed Ni55 high-voltage batteries (the former is 246Ah and the latter is 281Ah), Tang uses LFP batteries with a specific energy of 180Wh/kg to exceed 100kWh, which shows the amazing volume utilization of blade batteries. Similar to Seal’s high- and low-end models, both Tang EV’s batteries are 170Ah, but the number of strings is 166 and 200 respectively.
It is worth mentioning that BYD does not have its own charging piles, so its models all use the currently popular public charging piles to charge. The total voltage must be less than 750V to charge at more than 90% of the piles. The maximum voltage of 200 strings is 3.65*200=730V, which is close to the upper limit of 750V. Therefore, judging from the current infrastructure, the upper limit of the amount of electricity charged by LFP passenger cars may be 108.8kWh for a long time. Unless the material system is updated, for example, it is recently rumored that CATL’s M3P battery will be installed in the new Model 3, and the energy will be increased from 60kWh of LFP to 66kWh, an increase of about 10%. In that case, BYD’s LMFP blade battery is expected to achieve 120kWh Charged.
According to the size parameters of the model, Tang EV’s wheelbase of 2820 is the shortest, more than 100mm shorter than other models. However, its vehicle height of 1725mm is leading, so the height of its blade battery may be appropriately increased to meet the 170Ah capacity. In fact, due to factors such as vehicle platform development and cost reduction and efficiency improvement, the current blade battery size standard has been locked at 96013.5(14)90(102)mm, and the cell voltage is stable at around 3.2V. According to the above analysis results, the height of the 170Ah battery cell is increased to 102mm based on the 90mm height of the 150Ah battery cell, with a height increase of 11.3% to increase the capacity.
4.BYD TANG EV compare with Denza N7 battery
Although the Tang EV has a charged capacity of 108.8kWh, its comprehensive range is only 730km. This is because the Tang EV has a larger curb weight, reaching 2440kg. Although the Denza N7 only has 91.392kWh, its curb weight is 2320kg, which is 120kg lighter. Considering The system energy density is about 150Wh/kg. The 17.4kWh added by Tang EV requires a mass of 116kg, which is relatively close to 120kg.
It can be seen that by simply stacking batteries, although the energy has increased, the weight of the vehicle has also increased. In addition, Tang is a medium and large SUV, and the wind resistance is larger (0.3 or more), so its battery life is 702km longer than that of the Denza N7. It’s not big, and it’s not a big upgrade compared to the 715km of the 2022 Han EV (the Han EV has a power capacity of 85.44kWh, a curb weight of 2100kg, and a wind resistance of 0.233).
In addition to energy consumption, another thing worth noting is that the energy density of the Denza N7’s battery system has been reduced, to 140.6Wh/kg. This may be because the CTB takes the body structure mass into account. After all, after subsidies are withdrawn, the energy density of the battery system itself is no longer so important (previously, subsidies were linked to both system energy density and energy consumption), and there is no need to pursue this indicator too much in the reporting parameters. The use of CTB technology to combine the battery pack upper cover with the car body floor increases the available height space. With the blessing of blade batteries, a volume utilization rate of 77% is achieved. Then the charging capacity is increased by stacking batteries, thereby achieving High energy and long battery life are the unique features of N7.
You can know more about the LPF low temp solution from BYD self heating.
5.Sum from Vehiclethermal for Denza N7 CTB battery
BYD has always been an industry pioneer in stack batteries. The early e5 and e6 were stack batteries that exploited every opportunity, and the volume utilization rate was not high, even lower than 50%. It was not until the advent of the blade battery in 2020 that there was a real leap forward in technology. The battery volume utilization rate of the first-generation Blade in 2020 was 60%, which was astonishing. Later, with the support of CTB technology, the utilization rate increased to 66%, which is even more popular. Now, the volume utilization rate of Denza N7 has reached an astonishing 77%, exceeding the 72% of CATL Kirin battery. It has helped the LFP blade battery to increase the charge capacity to 91.392kWh, which is gradually breaking the ceiling of LFP passenger car charge capacity.
At present, Tang EV has achieved a charged capacity of 108.8kWh. With the continuous upgrading of blade batteries and CTB technology, using LMFP materials in the future, it is close to achieve 100kWh for cars and 120kWh for SUVs. Recently, the CEO of Lucid, a new American car-making brand, said in an interview with the media that electric vehicles are expected to achieve ultra-low energy consumption of 10kWh/100km in the next 10 years, so 100kWh is still expected to achieve a range of thousands of miles. Based on the current volume utilization rate of 77%, let us wait and see whether the blade battery can break through the near-limit number of 80%, and then install more batteries.