Battery Life & Energy Estimator
Battery Specifications
Used to calculate energy in Watt-hours (Wh).
Duty Cycle Profile
Estimated Battery Life
0 Days
0 months / 0 years
Average Current
0.00 mA
Across the full duty cycle
Daily Consumption
0.00 mAh
0.00 Wh / day
Cycle Time
0 min
0 cycles / day
Note: This is a theoretical estimate. Real-world battery life may be 10-30% lower due to battery self-discharge, voltage regulator inefficiency, and temperature effects.
Understanding IoT Power Consumption
How It's Calculated
The calculator uses the duty cycle method to find the average current:
Iavg = (Iactive × Tactive + Isleep × Tsleep) / (Tactive + Tsleep)
Battery life is then simply: Capacity / Iavg
Tips to Extend Battery Life
- Use Deep Sleep: Microcontrollers like ESP32 can drop from ~80mA to ~10µA in deep sleep.
- Reduce Transmit Power: Lower WiFi/BLE TX power if range allows.
- Optimize Payloads: Send smaller, less frequent data packets.
- Hardware Choices: Use LDOs or buck converters with low quiescent current (Iq).
- Disable Peripherals: Turn off ADC, I2C, or sensors when not actively reading.
Battery Chemistry Notes
- Alkaline (AA/AAA): ~2000-3000 mAh, but voltage drops steadily. Not ideal for 3.3V MCUs without a boost converter.
- Li-ion / Li-Po (18650, etc.): ~2000-3500 mAh, flat 3.7V discharge curve. Requires a protection circuit (BMS).
- LiFePO4: ~1000-2000 mAh, safer, 3.2V nominal. Great for solar-powered IoT.
- Self-Discharge: All batteries lose 1-5% charge per month even when disconnected.
Common Pitfalls
- Ignoring Regulator Quiescent Current: A cheap LDO might draw 5mA even when the MCU is asleep, draining the battery in days.
- Peak Current Spikes: WiFi transmission can spike to 300mA+. Ensure the battery can handle the peak without voltage sagging below the MCU's brownout threshold.
- Temperature: Battery capacity drops significantly in cold environments (e.g., outdoor sensors).
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