Power Consumption by Platform

Understanding your node's actual power consumption is essential for correctly sizing a solar system. These measurements are from community benchmarks - values vary by firmware version, radio activity, and configuration. 

 ESP32-based nodes 
 ESP32 nodes have higher baseline power draw than nRF52 devices but offer WiFi and faster processing. 

 
 
 State Factory defaults Optimized config Notes 
 
 
 Idle (radio listening) ~150 mA ~40 mA WiFi off, screen off, BT power reduced 
 Active receive (packet processing) ~180 mA ~55 mA Brief peak during processing 
 Transmitting @ 27 dBm ~280 mA ~280 mA TX power draw is fixed by hardware 
 Display on (OLED) +15 - 20 mA N/A (disabled) Disable for any unattended deployment 
 WiFi active +60 - 120 mA N/A (disabled) Disable unless serving TCP bridge 
 
 

 Key optimizations for ESP32 repeaters: 
 
 Disable WiFi: largest single saving for non-TCP deployments 
 Disable display: set screen timeout to 0 
 Reduce BT TX power: sufficient for app connection at short range 
 Result: ~150 mA factory → ~40 mA optimized = 3.75× improvement 
 

 nRF52840-based nodes 
 nRF52840 devices are the preferred choice for solar and battery-only deployments due to dramatically lower power draw. 

 
 
 State Factory defaults Optimized config Notes 
 
 
 Idle (radio listening) ~25 mA ~5 mA With deep-sleep radio polling 
 Active receive ~30 mA ~8 mA Processing packet 
 Transmitting @ 27 dBm ~120 mA ~120 mA TX power draw is fixed 
 Deep sleep (between polls) N/A ~0.2 mA With Repeater role sleep scheduling 
 GPS active +25 mA N/A (disabled) Disable GPS for repeaters 
 
 

 Key optimizations for nRF52 repeaters: 
 
 Enable Repeater role sleep scheduling: radio polls at configurable interval between transmissions 
 Disable GPS module (not needed for repeater operation) 
 Disable BLE advertising when not in setup mode 
 EasySkyMesh firmware (community fork): achieves ~5.5 mA average on Heltec V4.3 - the lowest known idle current for a Heltec device 
 

 Notable hardware benchmarks 

 
 
 Device MCU Average current (repeater, optimized) Notes 
 
 
 Heltec Mesh Node V4 ESP32-S3 ~40 mA Wi-Fi + BT disabled 
 Heltec Mesh Node V4.3 ESP32-S3 ~5.5 mA EasySkyMesh firmware only 
 Heltec T096 nRF52840 ~12 µA Deep sleep; new as of April 2026 
 RAK4631 WisBlock nRF52840 ~5 - 8 mA Standard MeshCore repeater firmware 
 LilyGo T-Echo nRF52840 ~8 mA GPS disabled, e-ink refresh minimal 
 Station G2 ESP32-S3 ~45 mA High TX power option; requires 15V PD power 
 
 

 Daily energy budget calculation example 
 To size your battery correctly: Wh per day = (mA × hours) / 1000 
 Example: RAK4631 running optimized at 6 mA average, 24 hours: 
 Energy per day = (6 mA × 24 h) / 1000 = 0.144 Ah/day = ~0.53 Wh/day @ 3.7V

Battery sizing for 5-day autonomy:
 0.144 Ah/day × 5 days = 0.72 Ah minimum
 With 80% depth-of-discharge: 0.72 / 0.8 = 0.9 Ah LiFePO4 minimum
 Practical recommendation: 5 - 10 Ah LiFePO4 for comfortable 5-day margin plus TX spikes
 

 Voltage and battery type reference 
 
 Chemistry Nominal voltage Temp range Cycle life Recommended for 
 
 LiFePO4 3.2V/cell −20°C to +60°C 2000+ cycles All outdoor deployments 
 LiPo (LiCoO2) 3.7V/cell 0°C to +45°C 300 - 500 cycles Indoor/portable only 
 NiMH AA 1.2V/cell −20°C to +50°C 500 - 1000 cycles Ultra-budget temporary nodes 
 
 
 LiFePO4 is strongly recommended for permanent outdoor deployments: it handles temperature extremes, has 4× longer cycle life than LiPo, and will not catch fire if overcharged or punctured.