Solar Radiosonde Power Budget

Configure parameters, analyze power usage, and simulate battery capacity over time

System Power Architecture

Solar Panel BQ25570 Power Management Boost Charger Buck LTO Battery 4.4V Microcontroller LoRa Radio GPS SHT31 0.5V, 50mA Charges Regulated 3.0V Bus

Block diagram showing power distribution: All components (MCU, LoRa Radio, GPS, SHT31) powered from the regulated 3.0V buck converter output of the BQ25570.

Operation Sequence Diagram

MCU GPS SHT31 LoRa TX LoRa RX -2s -1s 0s 1s 2s 4s 6s 8s 10s Sleep Active Sleep for remainder of cycle 2s 20ms 400ms 2s Wake Fix Data Start SHT31 Data Send Data Wait for Response Response Received MCU enters sleep mode

Swimlane sequence diagram showing the operation flow: Initial idle period (-2s to 0s), MCU wakes at 0s and activates peripherals in sequence (GPS → SHT31 → LoRa TX → LoRa RX), remaining active until all operations complete before entering sleep mode.

System Configuration

Battery Properties

3.0-5.5V range for 2S LTO configuration
Severe capacity reduction at -50°C
High impedance at -50°C

Energy Harvester IC (BQ25570)

Overall harvesting circuit efficiency
Continuous

Solar Panel

Per panel

Total: 1.0V @ 50mA (50mW)

Microcontroller

Wio E5 (includes LoRa radio)

GPS Module

SHT31 Sensor

LoRaWAN Transmission

Actions

Make changes to any parameters and click the button to recalculate.

Power Budget Summary

Component Average Current (mA) Daily Energy (mAh) Percentage

Power Consumption Distribution

Battery Capacity Over Time

Battery Voltage During One Cycle

Showing voltage droop due to internal impedance (2000mΩ at -50°C) during active operation

Note: This shows the voltage droop caused by the high internal resistance at extreme cold temperature. The 2Ω internal resistance creates significant voltage sag during peak current operations. The power budget calculation does not account for this voltage drop, which may cause components to behave unpredictably if voltage drops below minimum operating thresholds.

Weight Budget Summary

Component Weight (g) Quantity Total (g)
Total System Weight 0.0 g