How to improve the battery life of electric motorcycle lithium batteries in winter

As electric bicycles and electric motorcycles become more and more popular, consumers have also put forward higher requirements for the endurance of battery packs. Extending the battery life time can allow the vehicle to travel farther without frequent recharging is also the current consumer demand. In our daily life, we all want to have a longer battery life when using electric bicycles or electric motorcycles, especially in power. The cold environment reduces the battery activity and the battery life time is relatively reduced. How to improve it in winter What about the battery life? Here we talk about how to implement this method. We can try to improve the endurance of lithium-ion (Li-ion) battery packs through the following two methods: increase the total battery capacity or improve energy efficiency. Increasing the total battery capacity means using more or better battery cells, which will significantly increase the overall cost of the battery pack. And energy efficiency can provide planners with more available power without increasing capacity. There are two ways to improve energy efficiency: improve the accuracy of the state of charge and/or reduce current consumption. To get a longer battery life, the battery needs to release more energy; but if it is over-discharged, the battery will be permanently damaged. In order to prevent the battery from being over-discharged, it is important to accurately understand the battery capacity or state of charge. There are three ways to accurately measure the state of charge: The voltage measurement method is the simplest test method, but it also has low-precision overload conditions. Coulomb counts and integrates current over time. However, to complete the better accuracy of the charged state, it is necessary to perform regular full-idling learning cycles and calibrations, and the accuracy of the state will be affected by the current of self-discharge and standby. Low temperature and aging batteries will reduce the accuracy of the charge status. The battery capacity calibration technology developed by electronics can directly test the influence of discharge rate, temperature, life span and other factors after learning battery impedance. Therefore, even if the battery is aging and the temperature is too low, it can provide very accurate accuracy of the state of charge. The figure below shows the test results of the discharge status. The second way to improve energy efficiency is to reduce current consumption. As shown below. Bias power diagram of the entire system The 100 V LM5164 is a wide input, low quiescent current step-down DC-DC converter, which can protect the system from the potential transient effects of a nominal 48V battery, and is a 3.3 V microcontroller ( MCU) and BQ34Z100-G1 power supply. The input of LM5164 is controlled by two signals: REGOUT from BQ76940 and SYS from MSP430™ MCU. Either of these two signals is high, which will turn on Q1 and enable the input of the LM5164-thereby enabling the MCU power supply. When the circuit board has just been shipped from the factory and the battery management circuit board is powered on for the first time, it is in the factory state. Except for the BQ76940, the entire system is not powered on, and the current consumption is as low as 5-μA in the factory form. Press button S1 to set REGOUT to high level and turn on the system power. When the MCU is powered on, it will set SYS to a high level. Regardless of whether the BQ76940 is in the off mode or the normal mode, the entire system has a stable power supply. The user needs to turn on the MCU power to complete all the battery pack functions of the electric bicycle in standby mode, including charger connection/disconnection and load connection/disconnection. Q1 should be energized. To reduce the current consumption in standby mode, BQ76940 is set to shutdown mode through I2C command. Therefore, SYS is high, keeping Q1 in an energized state. LM5164 is set to low switching frequency to reduce switching loss, while MSP430 MCU is in a low power consumption form. All charger connection/disconnection and load connection/disconnection tests are completed by firmware. The standby current consumption is generally 50μA, as shown in the figure below. Standby mode current consumption Factory mode current consumption statement: The articles published on this site are all from the Internet and do not represent the views of this site. If there is any infringement, please contact to delete WeChat: Statement: Some pictures and content of articles published on this site are from the Internet , If there is any infringement, please contact to delete the previous article: Technology Sharing-How to Improve the Temperature Measurement Accuracy in the Battery Management System.