So instead of calling esp_deep_sleep_start() directly, I do some preparations first. I’ve seen various bug reports claiming that this doesn’t always turn off the WiFi or Bluetooth radio before going to deep sleep. However, I found that this is not sufficient to keep energy consumption to a minimum. In case you don’t know how: you configure a wakeup timer and then start the deep sleep mode: // How many minutes the ESP should sleepĮsp_sleep_enable_timer_wakeup (DEEP_SLEEP_TIME * 60L * 1000000L )

When running an ESP32 on a battery, you’ll want to keep it in deep sleep for as long as possible. In Arduino it’s just a one-liner: setCpuFrequencyMhz ( 80 ) Tip 5: Turn off everything in deep sleep Reducing the default clock speed from 160MHz to 80MHz can drop the energy consumption another 20%! If you can get away with a single-core ESP32, chances are you can get away with running that core at lower clock speeds. The same thing can be said for slower cores. Power consumption of the ESP32 according to Espressif Tip 4: Reduce the clock speedįewer cores consume less power.

The difference between dual-core and single-core? Well, a regular ESP32 will consume between 27-44mA when running at 160MHz while the single-core consumes about 30% less, coming in at 27mA-34mA. Yet the ESP32 has a dual-core processor.Ĭonsider buying a board that uses the single-core version of the ESP32 ( ESP32-SOLO-1). Most IoT devices are relatively simple and don’t require a lot of computing power. Tip 3: Pick the right ESP32 board (single-core) I also tested some LIPO batteries with a voltage of 3.7V, which seems to do the trick just fine. The ESP32 needs an input voltage of around 3.3V, so pick a battery that delivers a voltage close to this.Ī LiFePO4 would be perfect since it provides 3.2V. Still my favorite! Tip 2: Use the right battery Although these boards are discontinued, you can still find many alternatives online. These boards have ME6211 regulator that consumes just 40uA. These boards likely use a much more efficient LDO voltage regulator. Want to increase battery life? Then pick an ESP32 board that has a built-in battery connector. This was not tested with esp-idf directly. In this post, I’ll outline how I got an ESP32 to run for over 15 weeks (and counting) on a single 1000mAh battery.īefore we begin: the code samples shown in this post are for use with the Arduino framework.

The chip is a powerhouse, and with power comes great responsibility. Running an ESP32 on a battery is a tricky operation.

Battery drain wifi vs bluetooth