Introduction to battery-management systems- COURSERA WEEK 04 FINAL QUIZ

 Introduction to battery-management systems- COURSERA WEEK 04  FINAL QUIZ

1.

Question 1

Which of the following detection mechanisms could protect a battery pack from overcurrent? Select all that apply.

1 point

Contactor

Thermal fuse

Electronic protection

Resettable fuse

2.

Question 2

Suppose that a small passenger vehicle expends energy at a rate of 220Wh/mile while driving. If this vehicle's battery pack is charged at a 6.6kW rate, what is the rate of range added to the battery in "miles (of range) per hour"? Round your answer to the nearest "mph".

1 point

3.

Question 3

Suppose that a positive-electrode material has $\theta_{0\%}^{\rm pos}=0.99$ and $\theta_{100\%}^{\rm pos}=0.49$. If $\theta_k^{\rm pos}=0.59$, what is the present cell state-of-charge (in percent)? Round to the nearest percent.

1 point

4.

Question 4

Suppose that a lithium-ion cell having total charge capacity $Q=10$Ah is discharged at a rate of 2A for 30min. What is the net change in the cell's state of charge (in percent)? Round to the nearest percent.

H​int: I am looking for a signed quantity.

1 point

5.

Question 5

Consider the battery pack drawn below, where one cell has state-of-charge of 0% and the other cell has state-of-charge of 100%.

Which of the following statements is most accurate regarding the battery pack's state of charge?

1 point

Battery pack state of charge is 0% because we cannot discharge the battery pack without damaging the cell having state of charge of 0%

Battery pack state of charge should be the average of the two cell states of charge (i.e., 50%)

Battery pack state of charge is ill-defined, and the term should never be used

Battery pack state of charge is 100% because we cannot charge the cell having state of charge of 100%

6.

Question 6

Consider a cell having nominal voltage $v_{\rm nom}=3.8$V and total charge capacity $Q=25$Ah. If the BMS is designed to keep the cell's state of charge between 5% and 95%, and if the cell's present state of charge is 80%, what is the approximate remaining total energy in the cell (in Wh)? Round your answer to the nearest Wh.

1 point

7.

Question 7

Consider the HPPC test depicted on slide 3 of lesson 1.4.5 for $\Delta T=10$s and $I_{\rm chg}=I_{\rm dis}=20$A. If the cell voltages at times {0, 10$^+$, 20$^-$, 30$^-$, $30^+$, 40$^-$, and 50} seconds are {3.8, 3.42, 3.4, 3.79, 4.15, 4.19, and 3.81}, what is the HPPC charge resistance $R_{{\rm chg},\Delta T}$ of this cell (in m$\Omega$)? Round your answer to the nearest m$\Omega$.

1 point

8.

Question 8

Consider a cell having open-circuit voltage of 3.9V at its present state of charge, operational voltage limits of $v_{\rm min}=2.5$V and $v_{\rm max}=4.2$V, HPPC resistances of $R_{{\rm chg},\Delta T}=0.005\Omega$ and $R_{{\rm dis},\Delta T}=0.004\Omega$. What amount of discharge power (in W) does the HPPC method predict? Round your answer to the nearest W, and report a positive number.

1 point

9.

Question 9

A battery is built from four series-connected lithium-ion battery cells, where each cell has operational voltage limits $v_{\rm min}=2.0$V and $v_{\rm max}=4.15$V. If the present signed charge current limits of the four cells, computed via the HPPC approach, are {-95A, -91A, -93A, -92A}, what is the overall battery-pack absolute charge power capability (in W)? Round your answer to the nearest W and report a positive number.

1 point

10.

Question 10

Consider a two-cell series-connected battery pack where cell states of charge are $z_1=0.52$ and $z_2=0.49$ and where the cells have total charge capacity $Q_1=25$Ah and $Q_2=24$Ah. If $z_{\rm min}=0.1$, what is the maximum value of $z_{\rm low}$ (that is, what is $\max_{j}(z_{{\rm low},j})$) for this battery pack (in percent)? Round your answer to the nearest percent.

1 point

11.

Question 11

Consider a two-cell series-connected battery pack where cell states of charge are $z_1=0.52$ and $z_2=0.49$ and where the cells have total charge capacity $Q_1=25$Ah and $Q_2=24$Ah. If $z_{\rm min}=0.1$, and the cells can be considered to have constant OCV of 3.7V, what is the total battery discharge energy for this battery pack (in Wh)? Round your answer to the nearest Wh. (Note that this configuration is the same as in question 10, which might save you some math.)

1 point

12.

Question 12

Which of the following estimates attempts to estimate present capacity fade and/or power fade of the battery-pack cells?

1 point

State of power (SOP)

State of health (SOH)

State of life (SOL)

State of charge (SOC)