BQ27426: BQ27426: Question about AVG I/P LAST RUN

Wang Dong

Intellectual 600 points

Part Number: BQ27426

Tool/software:

Hello there.

I have some questions regarding the previous case's responses.

Please help me answer them.

1、Does Load Mode/select = 0x81 correspond to the AVG P LAST RUN register?

2、When Load Mode/select = 0x81, is AVG P LAST RUN used for FCC and RM simulations?

3、Regarding the difference between Load select = 0 and load select = 1, my understanding is as follows:
When load select = 0, the fixed values of the existing AVG I/P LAST RUN are used for simulations. These two registers will not be updated during the discharge period.
When load select = 1, after the discharge lasts for more than 500 seconds, these two registers will be updated, and the values in these two registers will be used for simulations.
Please confirm whether my understanding is correct?

If there are any errors, please tell me the specific differences.

4、In the TRM, regarding the update conditions for AVG I LAST RUN and AVG P LAST RUN, my understanding is that：

continuous discharge (with the discharge current > [Dsg Current Threshold]) for more than 500 seconds is required.

Only after that, the average calculation of I and P will be carried out at a cycle of 1 second, and AVG I LAST RUN and AVG P LAST RUN will be updated after the discharge ends.

Please confirm whether my understanding is correct?

If there are any omissions or errors, please tell me the detailed update conditions.

5、The unit of AVG P LAST RUN is 0.1h rate. After calculating with the formula Design Capacity/(AVG P LAST RUN * 0.1), is the unit mA? Why isn't it mW?

6、If the unit of the calculated AVG P LAST RUN is mA, then how does this register simulate FCC and RM in the Power model?

Hello there，针对之前case中的回复，有一些疑问，请帮忙解答下。

1、Load Mode/select=0x81,对应的寄存器是AVG P LAST RUN吗？

2、Load Mode/select=0x81,是使用AVG P LAST RUN进行FCC、RM仿真吗？

3、Load select=0和load select=1的区别,我的理解是:

load select=0时，使用已有的AVG I/P LAST RUN的固定值进行仿真。在放电期间不会去更新这两个寄存器。

load select=1时，放电超过500秒后，会更新这两个寄存器，并使用这两个寄存器的值，进行仿真。

请确认理解是否一致？如有错误，请告知具体的区别？

4、在TRM中，针对AVG I LAST RUN和AVG P LAST RUN的更新条件，我的理解是：需要连续放电(放电电流>[Dsg Current Threshold])，超过500秒以后，才会按照1秒的周期对I和P进行平均计算，并在放电结束后对AVG I LAST RUN和AVG P LAST RUN进行更新。请确认理解是否一致？如有遗漏或错误，请告知详细的更新条件？

5、AVG P LAST RUN的单位是0.1h rate，使用Design Capacity/(AVG P LAST RUN*0.1)的公式计算后，单位是mA吗？为什么不是mW？

6、如果AVG P LAST RUN计算后的单位是mA，那么该寄存器在在Power model下，如何对FCC、RM进行仿真？

6 months ago

0 Dominik Hartl11 6 months ago

TI__Guru 61186 points

#1: Depending on setting, the gauge will either use Avg I or Avg P Last Run for capacity predictions.

#2: Yes.

#3: No. Avg I and P Last Run will update whenever the gauge has enough discharge data to calculate a reasonable average. This is independent from Load Mode setting.

#4: The understanding is correct in principle.

#5: You need to use the Design Energy if you use Load Mode = 1, not Design Capacity. See TRM, table 7-9.

#6: It's not mA. It's cW (in native gauge units).

0 Wang Dong 6 months ago in reply to Dominik Hartl11

Intellectual 600 points

HI dominik,

Thanks for your support.

1、How is AVG P LAST RUN used for the simulations of FCC, RM, and RA Table? What are the formulas?

My understanding is as follows: First, use AVG P LAST RUN and the current voltage to calculate the current(Calc_i), and then conduct the simulation through the formula "V(DOD[i],T) = OCV(DOD[i],T) - Calc_i x R(DOD[i],T)".

Is my understanding correct?

Dominik Hartl11 said:
#2: Yes.

2、Based on your response, the differences between Load Select = 0 and Load Select = 1 were not mentioned. Let me re-describe the question:

2.1 When Load mode = 0 and Load Select = 0, how is AVG I LAST RUN updated? What parameters are used by the Fuelgauge IC for FCC and RM simulations?

2.2 When Load mode = 0 and Load Select = 1, how is AVG I LAST RUN updated? What parameters are used by the Fuelgauge IC for FCC and RM simulations?

2.3 When Load mode = 1 and Load Select = 0, how is AVG P LAST RUN updated? What parameters are used by the Fuelgauge IC for FCC and RM simulations?

2.4 When Load mode = 1 and Load Select = 1, how is AVG P LAST RUN updated? What parameters are used by the Fuelgauge IC for FCC and RM simulations?

Dominik Hartl11 said:
#3: No. Avg I and P Last Run will update whenever the gauge has enough discharge data to calculate a reasonable average. This is independent from Load Mode setting.

3、When Load mode = 1, is my understanding correct that the calculation formula for AVG P LAST RUN is Design Energy / (AVG P LAST RUN * 0.1), and its unit is mW?

Dominik Hartl11 said:
#5: You need to use the Design Energy if you use Load Mode = 1, not Design Capacity. See TRM, table 7-9.

1、AVG P LAST RUN是如何用于FCC、RM、RA Table仿真的？公式是什么？

我的理解是：先使用AVG P LAST RUN和当前的电压，计算出电流CalcI，再通过"

V(DOD[i],T) = OCV(DOD[i],T) - CalcI x R(DOD[i],T)"进行仿真。

理解是否正确？

2、根据您的回复，没有提取到Load Select=0和Load Select=1的区别。重新描述下问题：

2.1 Load mode=0，Load Select=0时，AVG I LAST RUN是怎么更新的？FuelgaugeIC的FCC、RM使用什么参数进行仿真的？

2.2 Load mode=0，Load Select=1时，AVG I LAST RUN是怎么更新的？FuelgaugeIC的FCC、RM使用什么参数进行仿真的？

2.3 Load mode=1，Load Select=0时，AVG P LAST RUN是怎么更新的？FuelgaugeIC的FCC、RM使用什么参数进行仿真的？

2.4 Load mode=1，Load Select=1时，AVG P LAST RUN是怎么更新的？FuelgaugeIC的FCC、RM使用什么参数进行仿真的？

Dominik Hartl11 said:
#3: No. Avg I and P Last Run will update whenever the gauge has enough discharge data to calculate a reasonable average. This is independent from Load Mode setting.

3、AVG P LAST RUN的计算公式为：Design Energy/(AVG P LAST RUN*0.1)，单位为mW。理解是否正确？

Dominik Hartl11 said:
#5: You need to use the Design Energy if you use Load Mode = 1, not Design Capacity. See TRM, table 7-9.

0 Dominik Hartl11 6 months ago in reply to Wang Dong

TI__Guru 61186 points

1: It's not quite as simple but the concept is correct.

2: Both Avg I and P are updated regardless of Load Mode / Select setting. Load Mode / Select impacts how the gauge uses this information, not how it is generated.

3: That's how you can convert the Avg P Last Run into an Energy unit, correct.

0 Wang Dong 6 months ago in reply to Dominik Hartl11

Intellectual 600 points

Hi Dominik,

Thanks for your support.

1、When the discharge lasts for more than 1000 seconds, what are the differences between load select = 0 and load select = 1 when the fuel gauge simulates FCC and RM?

Dominik Hartl11 said:
2: Both Avg I and P are updated regardless of Load Mode / Select setting. Load Mode / Select impacts how the gauge uses this information, not how it is generated.

2、What are the differences in the update conditions of the AVG I/P LAST RUN registers corresponding to Load Select = 0 and Load Select = 1?

Wang Dong said:
4、In the TRM, regarding the update conditions for AVG I LAST RUN and AVG P LAST RUN, my understanding is that：

continuous discharge (with the discharge current > [Dsg Current Threshold]) for more than 500 seconds is required.

Only after that, the average calculation of I and P will be carried out at a cycle of 1 second, and AVG I LAST RUN and AVG P LAST RUN will be updated after the discharge ends.

1、放电超过1000秒，fuelgauge 仿真FCC和RM时，load select=0 和load select=1有什么区别？

2、Load Select=0和Load Select=1，对应的AVG I/P LAST RUN寄存器的更新条件，有什么区别？

0 Dominik Hartl11 6 months ago in reply to Wang Dong

TI__Guru 61186 points

The gauge uses the average load (current or power) from the previous discharge (which caused an update to Avg I/P Last Run) to estimate capacity during a discharge, if Load Select = 0.

The gauge uses the present average load (from start of discharge) if Load Select = 1.

There is no difference in update conditions based on Load Select.

0 Wang Dong 6 months ago in reply to Dominik Hartl11

Intellectual 600 points

Hi Dominik，

Thanks for your support.

Combining all the issues in this case, the understanding is organized as follows:

When Select = 0, use AVG I/P LAST RUN for simulation. Update AVG I/P LAST RUN after the discharge stops.

When Select = 1,

if the discharge time is less than 500 seconds, use AVG I/P LAST RUN for simulation.

If the discharge time is more than 500 seconds, use the average current/power from the start of the discharge until now (NOW AVG I/P) for simulation.

Update AVG I/P LAST RUN with the average current/power (NOW AVG I/P) after the discharge stops.

Is the above understanding correct?

Wang Dong said:
4、In the TRM, regarding the update conditions for AVG I LAST RUN and AVG P LAST RUN, my understanding is that：

continuous discharge (with the discharge current > [Dsg Current Threshold]) for more than 500 seconds is required.

Only after that, the average calculation of I and P will be carried out at a cycle of 1 second, and AVG I LAST RUN and AVG P LAST RUN will be updated after the discharge ends.

当Select=0时，使用AVG I/P LAST RUN进行仿真。放电停止后，对AVG I/P LAST RUN进行更新。

当Select=1时，放电<500秒，使用AVG I/P LAST RUN仿真，放电>500秒后，使用放电开始到现在的平均电流/功率(AVG I/P)，进行仿真。当放电停止后，使用平均电流/功率AVG I/P对AVG I/P LAST RUN进行更新。

上述理解是否正确？

0 Dominik Hartl11 6 months ago in reply to Wang Dong

TI__Guru 61186 points

The gauge will use Avg I/P at the start of discharge for simulations for both Load Select 0 and 1. It will switch to present average discharge during a discharge, depending on Load Select. The 500s are about Avg I/P updates after a discharge.

0 Wang Dong 6 months ago in reply to Dominik Hartl11

Intellectual 600 points

Hi Dominik，

Sorry, I still don't understand your response.

1、Regarding the update conditions for the AVG I/P LAST RUN register: After the discharge lasts for more than 500 seconds, will the register be updated during the discharge or after the discharge ends?

2、When select = 0, is the AVG I/P LAST RUN register used for simulations?

3、When select = 1, is the AVG I/P LAST RUN register not used for simulations? Instead, is the average value from the start of the current discharge to the present used? Is it independent of the discharge time?

4、If statement 3 is incorrect, please tell me what values the Fuelgauge IC uses for simulations when Select = 1 and its relationship with the discharge time？

5、If statement 3 is correct, does it mean the response to question #2 at the beginning of this case is wrong?

Wang Dong said:
2、When Load Mode/select = 0x81, is AVG P LAST RUN used for FCC and RM simulations?

抱歉，对您的回复还是不理解。

1、AVG I/P LAST RUN寄存器更新条件：放电超过500秒后，在放电期间更新还是放电结束后更新？

2、select=0时，使用AVG I/P LAST RUN寄存器进行仿真？

3、select=1时，不使用AVG I/P LAST RUN寄存器进行仿真。而是使用本次放电开始到当前的平均值？与放电时间无关？

4、如果3错误，请告知Select=1时，FuelgaugeIC使用什么值进行仿真？与放电时间的关系？

5、如果3正确，那么之前的回复是错误的？

0 Dominik Hartl11 6 months ago in reply to Wang Dong

TI__Guru 61186 points

1. Avg I/P last run will be updated after discharge stops.

2. Load Select = 0: The gauge uses Avg I/P last run for simulations.

3. Load Select = 1: The gauge uses Avg I/P last run for the initial simulation at start of discharge (and during relax). Once discharge starts, the gauge starts calculating the present average discharge load and it will use this for subsequent simulations during the discharge. Note that the gauge will not update Avg I/P last run with the present average discharge during the discharge. These two parameters update after discharge.

0 Wang Dong 6 months ago in reply to Dominik Hartl11

Intellectual 600 points

HI Dominik

I understand，Thans。

1、When load select = 1, how much time is needed from the start of discharge to calculate the current average discharge load?

2、When load select = 1, is there a corresponding register in the Fuelgauge IC to obtain the current average discharge load?

3、If there is no corresponding register for #2, then how can the current average discharge load be calculated? Is it the integral of current * voltage?

1、load select=1时，放电开始-->计算出当前的平均放电负载，需要多久的时间？

2、load select=1时，当前的平均放电负载，有没有对应的寄存器可以获取？

3、如果#2没有对应的寄存器，那么如何计算当前的平均放电负载？电流*电压的积分？

0 Dominik Hartl11 6 months ago in reply to Wang Dong

TI__Guru 61186 points

#1: It starts immediately.

#2: No.

#3: It's effectively the passed charge / time

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BQ27426: BQ27426: Question about AVG I/P LAST RUN