Due to regulatory requirements, electric vehicles in the United States and Europe require corresponding OBD diagnostic requirements for electric vehicles. Therefore, in the United States, a data logger for Nissan LEAF can be developed based on the ELM-327 Bluetooth converter, and a LEAF Spy is produced. software. And there is such a car owner who has made a detailed record of the use of his vehicle, link: http://daveinolywa.blogspot.com/2018/06/ contains a more detailed situation of a car 1) Vehicle dashboard data 2) Diagnostic data obtained by LEAF Spy (before charging) 3) Charging process: This graph includes power (multiply the battery voltage and charging current during charging), SOC (from 20% to 70%) and battery temperature (from 23° to about 45°) 4) End of charging status After doing some statistics on some of the data he shared, I got some very interesting content. Our data includes the following content: dashboard mileage, dashboard SOC, real diagnosis SOC and remaining energy. After doing a point map, the following conclusions are initially obtained 1) Nissan’s engineers intercepted the SOC curve and converted the SOC buffer. About 10% of the SOC is hidden. As shown in the figure below, there is about 4% of the top space, which requires a total of 14% and 15% of the buffer. The above paragraph: Mainly consider the energy recovery power at different temperatures, but also consider the uniformity, fast charging can hardly reach this range The following paragraph: The buffer is left enough, so that after the vehicle displays 1% SOC, there is still a display setting of --%. At this time, the available energy is still 4.5Kwh, which to some extent gives you the anxiety of the previous mileage Some sense of security 2) The meter displays the graph of SOC and available mileage In this figure, there are some parameter changes. In the following analysis, we can see that the SOC and the remaining energy of diagnosis are dominant. A lot of temperature corrections have been made here. Due to the difference in battery temperature, the same SOC is When the battery temperature is different, there is a big dispersion. Therefore, Nissan puts a battery temperature display on the dashboard to let you understand the overall change of this value. 3) SOC and available energy value From the first figure, it is obvious that there is an intercept, which is the reserved energy, and the conversion of available energy is marked by linearity. 4) SOH situation In calculating SOH, some distinctions are made here, considering the characteristics of capacity and internal resistance, so the statistics in the following table, divided into mileage and calendar life, here are both capacity detection and internal resistance growth detection, based on these two data together Correct the value of SOH. Nissan’s specific algorithm can be further evaluated later 5) Discrete battery voltage When the bottom Soc is close to emptying, the pressure difference of 57mV, the overall situation is not bad. In the later stage of dispersion, when considering the balance, you can use this voltage diagram to see its mandatory characteristics Summary: Through this software, the basic battery status and some protection strategies for the early, mid and late battery life are still at a glance. I have time to find some old cars to see the data situation and the effectiveness of battery management. In Github, there is also a forwarding terminal made through a mobile phone, which can be processed by collecting these data on the server. UV Film,UV Screen Protector,UV Curing Screen Protector Shenzhen Jianjiantong Technology Co., Ltd. , https://www.jjtphonesticker.com
July 19, 2023