MC33774A Pause balancing feature

[MarkFan]

Hi ,

      When I enable the cell balancing function, the battery measurement voltage becomes unstable, So I referent the datasheet and enable  auto pause .

CfgRegOffset = 0x1400, CfgReg = 0x7d3

CfgRegOffset = 0x1401, CfgReg = 0x7fff => 0xffff

but when I enable auto pause  PAUSEBAL in ALLM_APP_CTRL, All cell voltage become max value 5046mV, disable  PAUSEBAL, measurement function no problem,  don't know why?

thanks for any help.

Best regards,

Mark 

[MarkFan]

Hi Tomas,

     Thanks for your reply, I try to print out the register config than auto-balancing working fun.

     I found add debug message as below could get the cell voltage 

     Phy_774a_SpiSendTpl3Msg RegAddr = 0x1400, RegData = 0x7d3
     Phy_774a_SpiSendTpl3Msg RegAddr = 0x1401, RegData = 0xffff
      Phy_774a_SpiSendTpl3Msg RegAddr = 0x1401, RegData = 0xffff 

     Once I remove the debug message,  the all cell voltage become 5046.

      Don't know why? even add delay 1ms after send TPL command.

      And no need to add debug message while turn off the auto-balancing feature.

      Thanks for any help.

Best regards,

Mark

[TomasVaverka]

Hi Mark,

Two other questions to better understand what is going on.

1. Can you check what is CT register value: is 0x8000 or 0x8001. Then calculate result is 5046 as mentioned as below?

Once I remove the debug message, the all cell voltage become 5046.

2. The pause time is 5ms according to your configuration, and the interval between two APP commands must at least 9ms. Maybe invalid values are obtained due to insufficient delay.
The second APP command needs to restore the balance.

Phy_774a_SpiSendTpl3Msg RegAddr = 0x1401, RegData = 0xffff
Phy_774a_SpiSendTpl3Msg RegAddr = 0x1401, RegData = 0x7fff

BRs, Tomas

[MarkFan]

Hi Tomas,

     Thanks for your reply.

1. Can you check what is CT register value: is 0x8000 or 0x8001.  

 Ans: 0x8000.

2. I am referencing the measurement sequence from the S32K358 EVB, without understanding the details. anyway, I can get cell voltage correctly.

Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1400, RegData = 0x7d3   => SOC
Phy_665a_Schedule_Time(drvConfig, 100U);
Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1401, RegData = 0xffff       => ? config after SOC
Phy_665a_Schedule_Time(drvConfig, 4000U);                                     => delay how to config timer? why 4000?
Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1401, RegData = 0xffff       => ? why need to send again?
Phy_665a_Schedule_Time(drvConfig, 300U);                                        => delay? 
Bcc_774a_NOP_Msg();

I enable the auto-pause feature, the sequence as below as you  suggestion, however I still got 5048 for my cell voltage.

Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1400, RegData = 0x7d3
Phy_665a_Schedule_Time(drvConfig, 100U);
Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1401, RegData = 0xffff
Phy_665a_Schedule_Time(drvConfig, 4000U);
Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1401, RegData = 0x7fff   => 0xffff -> 0x7fff
Phy_665a_Schedule_Time(drvConfig, 5000U);    => add delay
Bcc_774a_NOP_Msg();

Don't why I add debug message to print out the message after Phy_774a_SpiSendTpl3Msg(),

could get cell voltage correctly under auto-pause config.

Thanks for any help.

Best regards,

Mark

[TomasVaverka · Accepted solution]

Hi Mark,

I think the delay time is not enough, try out the process I suggested below:

Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1400, RegData = 0x7d3
Phy_665a_Schedule_Time(drvConfig, 100U);
Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1401, RegData = 0xffff
Phy_665a_Schedule_Time(drvConfig, 9000U); or  check  until  PRMM_MEAS_STAT. APPRDYVC==1
Phy_774a_SpiSendTpl3Msg : RegAddr = 0x1401, RegData = 0x7fff   
Phy_665a_Schedule_Time(drvConfig, 300U);    => add delay
Bcc_774a_NOP_Msg();

BRs, Tomas

[MarkFan]

Hi Tomas,
Thasnk for your help.
I check the RMM_MEAS_STAT. APPRDYVC==1,
It fixed the problem. much thanks again.

Best regards,
Mark

[TomasVaverka]

Hi Mark,

We have not encountered this issue before. Please share your software code flow, register configuration and hardware details.

BRs, Tomas