Budget battery life from duty cycle

Steps

Screens captured against Python 3 in your browser (JupyterLite) JupyterLite 0.6.4, Python (Pyodide) in Chromium 151, executed in browser on 2026-10-08; captureSource playwright:jupyterlite on 2026-10-08; the tool may have moved on — the text steps are the contract.

1. 1 Step 1

   Do

   Run the first code cell in the JupyterLite notebook editor and inspect the input record.

   You will see

   Synthetic Falstad model (seed 0), 5 V, 100 Hz, 20% duty. active=4.978865 mA; sleep=0.050050 mA. Energizer CR2032: typical 254 mAh to 2.0 V. Rating condition: 15 kΩ at 21 °C; ~0.2 mA load. STEP 1 inputs and their limits recorded

   Why it matters

   The capacity rating condition and measured current source limit what this calculation can claim.

2. 2 Step 2

   Do

   Run the second code cell in the notebook editor and inspect the weighted-current calculation.

   You will see

   I_avg = duty*I_active + (1-duty)*I_sleep. active share=0.995773 mA. sleep share=0.040040 mA. at 20% duty: I_avg=1.035813 mA. STEP 2 weighted current computed

   Why it matters

   A full-cycle current budget must weight each state by its duration.

3. 3 Step 3

   Do

   Run the third code cell in the notebook editor and inspect the ideal-life estimate.

   You will see

   Ideal life = rated capacity / average current. capacity=254 mAh; average=1.035813 mA. life=245.22 h = 10.22 days. continuous active life=51.02 h; continuous sleep=5074.93 h. STEP 3 ideal budget calculated

   Why it matters

   The ideal division gives a screening estimate in hours, with no pulse-load correction.

4. 4 Step 4

   Do

   Run the fourth code cell in the notebook editor and inspect the sweep table and plotted curve.

   You will see

   duty % | avg mA | ideal days 0 | 0.050 | 211.46 10 | 0.543 | 19.49 20 | 1.036 | 10.22 30 | 1.529 | 6.92 40 | 2.022 | 5.24 50 | 2.514 | 4.21 60 | 3.007 | 3.52 70 | 3.500 | 3.02 80 | 3.993 | 2.65 90 | 4.486 | 2.36 100 | 4.979 | 2.13 STEP 4 eleven-point sensitivity sweep plotted

   Why it matters

   Changing duty across eleven cases shows sensitivity beyond one nominal point.

5. 5 Step 5

   Do

   Run the fifth code cell in the notebook editor and compare the design changes.

   You will see

   baseline=10.22 days at 20% duty. half sleep current=10.42 days. half active current=19.67 days. half usable capacity=5.11 days. Capacity rating condition differs from this ~1 mA model. STEP 5 sensitivity and boundary compared

   Why it matters

   The dominant current term and usable capacity bound the decision.