State of Health (SOH) monitoring in EV Technology - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to read the battery voltage for SOH calculation.

EV Technology

voltage = read_sensor([1])

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Abattery_voltage_sensor

Btemperature_sensor

Ccurrent_sensor

Dspeed_sensor

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a sensor that measures current or temperature instead of voltage.

The battery voltage sensor is used to measure voltage, which is essential for SOH monitoring.

2fill in blank

medium

Complete the code to calculate SOH percentage from capacity values.

EV Technology

soh = ([1] / nominal_capacity) * 100

Drag options to blanks, or click blank then click option'

Avoltage

Bnominal_capacity

Ccurrent_capacity

Dtemperature

Attempts:

3 left

💡 Hint

Common Mistakes

Using nominal capacity instead of current capacity in the numerator.

SOH is calculated by dividing the current capacity by the nominal capacity and multiplying by 100 to get a percentage.

3fill in blank

hard

Fix the error in the SOH update function by completing the missing keyword.

EV Technology

def update_soh([1]):

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Aself

Bbattery

Ccapacity

Dvoltage

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting 'self' causes errors when accessing instance data.

In a class method, 'self' must be the first parameter to access instance variables.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps cell IDs to their SOH values above 80%.

EV Technology

healthy_cells = {cell_id: [1] for cell_id, [2] in cell_data.items() if soh > 80}

Drag options to blanks, or click blank then click option'

Asoh

Bsoh_value

Dcapacity

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names for unpacking and value.

The dictionary comprehension uses 'soh' as the value and unpacks 'soh_value' from the items.

5fill in blank

hard

Fill all three blanks to filter and map battery cells with SOH below 50%, returning their IDs and SOH.

EV Technology

low_soh_cells = [1](cell_id: [2] for cell_id, [3] in cells.items() if soh < 50)

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Adict

Bsoh

Dcapacity

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong function instead of dict(), or mismatching variable names.

We use dict() to create a dictionary from a generator expression unpacking cell_id and soh.

Practice

1. What does State of Health (SOH) monitoring primarily measure in electric vehicle batteries?

easy

A. The current speed of the vehicle

B. The remaining battery capacity compared to when it was new

C. The temperature inside the battery pack

D. The total distance the vehicle has traveled

Solution

1. Step 1: Understand SOH definition

   SOH measures how much battery capacity remains compared to its original capacity.

2. Step 2: Differentiate from other metrics

   Speed, temperature, and distance are unrelated to SOH's main purpose.

3. Final Answer:

   The remaining battery capacity compared to when it was new -> Option B

4. Quick Check:

   SOH = Remaining capacity % [OK]

Hint: SOH = battery health as percentage of original capacity [OK]

Common Mistakes:

• Confusing SOH with vehicle speed
• Mixing SOH with battery temperature
• Thinking SOH measures distance traveled

2. Which of the following is the correct way to represent SOH as a percentage in a monitoring script?

easy

A. soh = (battery_capacity / original_capacity) * 100

B. soh = battery_capacity / original_capacity

C. soh = battery_capacity - original_capacity

D. soh = battery_capacity + original_capacity

Solution

1. Step 1: Calculate SOH as a percentage

   SOH is the ratio of current to original capacity multiplied by 100 to get a percentage.

2. Step 2: Check formula correctness

   Only soh = (battery_capacity / original_capacity) * 100 correctly multiplies the ratio by 100 to express percentage.

3. Final Answer:

   soh = (battery_capacity / original_capacity) * 100 -> Option A

4. Quick Check:

   Percentage = ratio * 100 [OK]

Hint: Multiply ratio by 100 to get percentage [OK]

Common Mistakes:

• Forgetting to multiply by 100
• Using subtraction instead of division
• Adding capacities instead of dividing

3. Given the following code snippet, what will be the output?

original_capacity = 100
battery_capacity = 85
soh = (battery_capacity / original_capacity) * 100
print(f"SOH: {soh:.1f}%")

medium

A. SOH: 85.0%

B. SOH: 0.85%

C. SOH: 100.0%

D. SOH: 185.0%

Solution

1. Step 1: Calculate SOH value

   85 divided by 100 equals 0.85, multiplied by 100 equals 85.0.

2. Step 2: Format output string

   The print statement formats SOH to one decimal place, showing '85.0%'.

3. Final Answer:

   SOH: 85.0% -> Option A

4. Quick Check:

   0.85 * 100 = 85.0 [OK]

Hint: Divide then multiply by 100 for percentage output [OK]

Common Mistakes:

• Misreading decimal as percent
• Adding capacities instead of dividing
• Ignoring formatting precision

4. Identify the error in this SOH calculation code snippet:

original_capacity = 100
battery_capacity = 90
soh = battery_capacity / original_capacity * 100
print("SOH is " + soh + "%")

medium

A. Missing parentheses around division

B. Incorrect formula for SOH calculation

C. Using print without parentheses

D. Type error when concatenating string and float

Solution

1. Step 1: Analyze SOH calculation

   The formula is correct; division and multiplication order is fine without extra parentheses.

2. Step 2: Check print statement

   Concatenating string and float without conversion causes a TypeError.

3. Final Answer:

   Type error when concatenating string and float -> Option D

4. Quick Check:

   Convert float to string before concatenation [OK]

Hint: Convert numbers to strings before concatenation [OK]

Common Mistakes:

• Assuming formula is wrong
• Ignoring type conversion in print
• Thinking print syntax is incorrect

5. You want to alert the maintenance team if SOH drops below 70%. Which code snippet correctly implements this check?

soh = 65
if soh < 70:
    print("Alert: Battery SOH is low!")
else:
    print("Battery SOH is healthy.")

hard

A. The code alerts when SOH is above 70%

B. The code alerts only when SOH is exactly 70%

C. The code correctly alerts when SOH is below 70%

D. The code has syntax errors and won't run

Solution

1. Step 1: Understand the condition

   The if statement checks if SOH is less than 70, which is true for 65.

2. Step 2: Verify output behavior

   Since 65 < 70, it prints the alert message correctly.

3. Final Answer:

   The code correctly alerts when SOH is below 70% -> Option C

4. Quick Check:

   soh < 70 triggers alert [OK]

Hint: Use < 70 to check low SOH alert [OK]

Common Mistakes:

• Using <= instead of < causing off-by-one
• Confusing alert condition direction
• Assuming syntax error due to < symbol