Enter IoT Power Inputs
Example Data Table
| Scenario | Voltage (V) | Battery (mAh) | Active mA / s | TX mA / s | RX mA / s | Sleep mA | Cycle (s) | Fleet |
|---|---|---|---|---|---|---|---|---|
| LoRa Soil Sensor | 3.7 | 2400 | 8 / 3 | 120 / 2 | 14 / 1 | 0.02 | 900 | 50 |
| Asset Tracker | 3.7 | 3000 | 18 / 8 | 180 / 4 | 20 / 2 | 0.06 | 300 | 200 |
| Smart Meter Node | 5.0 | 5000 | 25 / 5 | 220 / 1.5 | 30 / 1.5 | 0.10 | 60 | 500 |
You can paste any example values into the form and compare battery life, fleet energy, and operating cost.
Formula Used
Sleep Duration = Cycle Length − (Active Duration + TX Duration + RX Duration)
Average Load Current = [(Active Current × Active Time) + (TX Current × TX Time) + (RX Current × RX Time) + (Sleep Current × Sleep Time)] ÷ Cycle Length
Average Source Current = Average Load Current ÷ Regulator Efficiency
Average Power = Supply Voltage × Average Source Current
Energy per Cycle = Voltage × Current × Time, summed across all states and adjusted for efficiency losses
Daily Energy = Average Power × 24
Effective Battery Capacity = Rated Capacity × Derating × (1 − Reserve)
Battery Life (hours) = Effective Battery Capacity ÷ Average Source Current
These formulas assume a repeating duty cycle, a stable supply voltage, and the same operating pattern throughout the selected year.
How to Use This Calculator
Enter the device supply voltage and rated battery capacity first. Add derating, reserve, and regulator efficiency to reflect real deployment losses.
Fill in current and duration values for active, transmit, and receive states. Enter the sleep current and full cycle length in seconds.
Set fleet size, annual operating days, electricity price, and carbon intensity. These values help extend the analysis from one node to the entire deployment.
Press the calculate button. The page shows the result above the form, a detailed output table, and a Plotly graph for daily state energy.
Use the CSV button to export tabular inputs and outputs. Use the PDF button to save the visual summary for reporting or design reviews.
FAQs
1. What does this calculator measure?
It estimates average current, energy per cycle, daily energy, battery life, annual fleet usage, cost, and emissions for connected devices using repeating duty cycles.
2. Why are active, transmit, receive, and sleep states separated?
Each state draws different current. Splitting them gives a more realistic average than using one current value for the whole operating cycle.
3. What is battery derating?
Battery derating reduces rated capacity to reflect temperature, aging, discharge limits, and field uncertainty. It helps avoid overly optimistic runtime estimates.
4. Why include a battery reserve percentage?
Reserve keeps part of the capacity unused. That buffer supports maintenance planning, protects battery health, and lowers the risk of unexpected shutdowns.
5. What does regulator efficiency change?
Poor efficiency means the source must deliver more current than the load uses. The calculator adjusts source-side current and energy to include that overhead.
6. Can I use this for mains-powered gateways?
Yes. Enter a large effective capacity or focus on energy and cost outputs. Battery life matters less, but power and annual consumption remain useful.
7. How accurate are the results?
Accuracy depends on the current values, durations, and assumptions you enter. Use measured lab or field data for stronger planning decisions.
8. What does the graph show?
The graph shows how much daily energy each state consumes. It makes it easier to see whether radio activity or sleep leakage dominates power use.