Li-Ion Battery Charger solution using the MSP430
Harman Grewal MSP430 Products
ABSTRACT
Rechargeable batteries are now widely used as the power supply source in many portable electronic equipments such as Laptops, cell phones and digital cameras.Charging circuits depend on the batterys chemistry and the most popular rechargeable batteries are Nickel-Cadmium (NiCd), Nickel-Metal-Hydride (NiMH), and Lithium-Ion(Li-Ion). This application report discusses the method to charge a Li-Ion battery using the MSP430 microcontroller.Li-Ion is rapidly becoming the chemistry of choice for portable applications because of its high capacity-to-size ratio and a low self discharge characteristic. There are a variety of battery charging solutions such as power management ICs, MCU controlled or even logic devices. The MCU controlled charging method offers its advantage as a safe charging, time efficient and low cost solution.Battery capacity, C, expressed in mA hours, is a measure of battery life between charges. Battery currenthas the units of C-Rate. For example, a 500 mA-h battery has a C-Rate of 500mA. The current corresponding to 1C is 500 mA and for 0.1C is 50 mA.A Li-Ion battery charging process consists of three stages:
MSP430微控制器讲座:
锂离子电池充电器的解决方案
作者:雷奥
摘要
可充电电池目前广泛使用的电源供应来源在许多便携式电子设备,如笔记本电脑,手机和数码相机.充电电路取决于电池化学和最流行的可充电电池是镍镉(镍镉) ,镍氢化物(镍氢电池)和锂离子( Li - Ion ) 。本应用报告讨论的方法,收取锂离子电池使用的MSP430 微控制器.锂离子电池正迅速成为化学便携式应用的选择,因为它的高容量的大小比例和低自放电特性。有各种各样的电池充电解决方案,如电源管理芯片 ,微控制器控制,甚至逻辑器件。与其它几种方法相比较,利用MCU微控制器设计、控制实现的锂离子电池充电器具有充、放电安全、效率高、功耗低和可现场升级等优点。电池充电率决定于容量。例如,一个500mA的电池的1C充电率为500mA,1C对应充电电流为500mA而0.1C对应50mA,锂电池的充电过程包括以下步骤:
缓慢充电阶段:预充电阶段充电电流为0.1C。
快速充电阶段:恒流充电阶段的电流为1C。
恒定电压充电阶段。