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BQ4050EVM-561: 关于bq4050电量学习

Part Number: BQ4050EVM-561

在evm板上,对单节电池进行了电量学习,并拿到GPC_CEDV文件。

现在将4节电池串在一起,然后根据《TI电量计应用指导》文档,修改了EMF和EDVR0的值。4节串联的电池充满电后,放电到3.1V,甚至放到2.8V后,EDV2和EDV1都没有亮红色,这是为什么呢?

单节电池满电放电后,EDV2会亮红色:

单节电池的学习报告:

7652.GPC_CEDV.txt
GPC CEDV tool, rev=60		
Configuration used in present fit		
ProcessingType=1		
NumCellSeries=1		
CellTermV=3000		
LearnSOC%=10		
FitMaxSOC%=12		
FitMinSOC%=6		
ChemType=1		
ElapsedTimeColumn=0		
VoltageColumn=1		
TemperatureColumn=2		
CurrentColumn=3		
		
CEDV parameters resulting from the fit. If EDVV bit is set to 1, EMF and EDVR0 have to be multiplied by the number of serial cells when written to data flash		
		
EMF	3582	
EDVC0	132	
EDVC1	0	
EDVR1	992	
EDVR0	484	
EDVT0	609	
EDVTC	11	
VOC75	3935	
VOC50	3808	
VOC25	3752	
		
		
Recommended SOC deviation tolerance at EDV2 point is  < 5% for low temperature and <3% for room and high temperature		
		
Deviations for this set of parameters are given below for each file		
		
file	SOC error, %	pass
roomtemp_lowrate.csv	-0.118295471881373	1
roomtemp_highrate.csv	-0.310936483014437	1
hightemp_lowrate.csv	0.103482113199268	1
hightemp_highrate.csv	0.978585026499113	1
lowtemp_lowrate.csv	0.377752707353737	1
lowtemp_highrate.csv	-0.713995294834259	1
		
Deviations are within recomended range. CEDV parameters are suitable for programming the gauge		
		

根据《TI电量计应用指导》来修改 EMF 和 EDVR0 值:

但电池放电电压在3.1V,甚至2.8V后,出没有见EVD2或EVD1亮红色:

请问,这是什么原因呢?

  • 您好,请确认您放电电流是否正常。

  • 学习过程中,是利用电子负载的,设置为400ma。4节串联电池放电到12V(平均每节电池到了3V),此时,电池还能稳定地放400ma的电流。

    目前,GPC_CEDV文档写到单节电池上,是可以正常学习电量的;主要问题是4节串联时,它会一直放电,直到shutdown了,也看不到EDV2变红色。

    CEDE_cfg参数的EMF 和 EDVR0 值,也根据《TI电量计应用指导》来修改 EMF 和 EDVR0 值:

    单节电芯的值为:

    EMF = 3582 和 EDVR0 = 484

    4节串联的值为:

    EMF = 3582*4=14328  和 EDVR0 = 484*4=1936

    是不是还有其它地方没有设置对?CEDV Gauging Configuraion里,设置如下:

    EDV_PACK是不是要设置为1?

  • 您好,建议将EVD_PACK 使能,EDV_PACK=0,那么写入data flash时EMF和EDVR0不需要乘以串行单元的数量?

  • 当EDV_PACK=1时,充满电(FC=1),当放电时,EDV2 和EDV1会立刻会红色,怎么会这样的呢?

  • 您好,

    "When EDV_PACK is 1, the gauge will multiply each EDVx with the number of cells to get the threshold so for the customer’s case, they’d have to multiply EDV2 (if compensation was not enabled – if it was, then the gauge will adjust this also for temperature and load) by three and compare this with the total pack voltage to know when the 7% point was reached."

    Based on these descriptions which are describing how the code calculates the EDVx, it seems to be pack-based when ADV_PACK = 1. I hope this helped clarify it for you.