My battery drains too fast

Step 1: Measure actual power draw Use a USB inline power meter to measure real current draw. This immediately shows whether you have a software config problem or a hardware issue. Expected draw by hardware Hardware Typical active draw ESP32 (T-Beam, Heltec), no display, no BT 40-55 mA ESP32 with OLED display on +20 mA nRF52840 (RAK4631, T-Echo, T114) 8-15 mA Power drain checklist Screen on? Set timeout to 0. Bluetooth enabled? Disable if not needed. GPS polling? Disable or set a long interval. WiFi enabled (ESP32)? Disable. Position broadcast interval too short? Set to 30+ minutes on battery. Battery sizing Battery (mAh) divided by draw (mA) = hours of runtime. 1000 mAh at 40 mA = 25 hours; at 10 mA = 100 hours. Switching from ESP32 to nRF52840 hardware typically gives 4x longer life on the same battery.