我用bq76920做了一个检测3节电池的方案,当电池总电压为3.5v(每节单电池是通过电阻分压来接入的) 或更低的时候显示就出现较大的偏差:
9.2V的电压打印如下:
i= 0-------CellVoltage = 3061
i= 1-------CellVoltage = 3065
i= 2-------CellVoltage = 49
i= 3-------CellVoltage = 48
i= 4-------CellVoltage = 3050
Battery_Patch_Voltage = 9295
3.5V的电压打印如下:(0,1相差快200MV)
i= 0-------CellVoltage = 1211
i= 1-------CellVoltage = 1068
i= 2-------CellVoltage = 48
i= 3-------CellVoltage = 48
i= 4-------CellVoltage = 1208
Battery_Patch_Voltage = 3587
3.0V的电压打印如下:
i= 0-------CellVoltage = 1049
i= 1-------CellVoltage = 771
i= 2-------CellVoltage = 48
i= 3-------CellVoltage = 48
i= 4-------CellVoltage = 1047
Battery_Patch_Voltage = 2967
2.0V的电压打印如下:
i= 0-------CellVoltage = 714
i= 1-------CellVoltage = 48
i= 2-------CellVoltage = 48
i= 3-------CellVoltage = 49
i= 4-------CellVoltage = 1226
Battery_Patch_Voltage = 2088
1.5V的电压打印如下:总电压都相差200MV了
i= 0-------CellVoltage = 563
i= 1-------CellVoltage = 48
i= 2-------CellVoltage = 48
i= 3-------CellVoltage = 48
i= 4-------CellVoltage = 655
Battery_Patch_Voltage = 1366
日本客户要求能检单节0.5V
用万用表实测各个点的电压是对的,为什么读出来的值相差这么大?电压高就不会出现这个情况
还有如果我吧第二节不接到VC2,8v的时候显示
i= 0-------CellVoltage = 2680
i= 1-------CellVoltage = 746
i= 2-------CellVoltage = 48
i= 3-------CellVoltage = 48
i= 4-------CellVoltage = 4618
Battery_Patch_Voltage = 8044
实测VC1电压是对的,VC2电压有2.22v ,没接电池进来怎么还有这么高的电压
这些个是没有打开cell banlance的,
以上的这些情况要怎么处理啊,谁帮指导下!