# 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

The figures below are approximate field measurements and vary with firmware, settings, and transmit duty cycle - measure your own device for an accurate number.

<table id="bkmrk-hardwaretypical-acti"><thead><tr><th>Hardware</th><th>Typical active draw (approximate)</th></tr></thead><tbody><tr><td>ESP32 (T-Beam, Heltec), no display, no BT</td><td>~40-55 mA</td></tr><tr><td>ESP32 with OLED display on</td><td>+10-20 mA</td></tr><tr><td>nRF52840 (RAK4631, T-Echo, T114)</td><td>~8-15 mA</td></tr></tbody></table>

## Power drain checklist

- Screen on all the time? Set a short screen timeout (e.g. 10-30 seconds) so the display sleeps. Note: a timeout of 0 usually means never sleep - avoid it on battery.
- 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 roughly 4x longer life on the same battery (approximate; the exact ratio depends on your settings and usage).