From d1e4e6f17e3034f62d3c9dab0ce413ea871e199c Mon Sep 17 00:00:00 2001 From: Jannik Beyerstedt Date: Mon, 5 Apr 2021 20:53:35 +0200 Subject: [PATCH] [DOC] add real-life battery endurance --- README.md | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index b8e843a..fd53f45 100644 --- a/README.md +++ b/README.md @@ -26,7 +26,7 @@ tar -xzf xtensa-esp32-elf-osx-1.22.0-80-g6c4433a-5.2.0.tar.gz rm xtensa-esp32-elf-osx-1.22.0-80-g6c4433a-5.2.0.tar.gz ``` -Prepare toolchain (Debian, Ubuntu) (ubuntu devel vm): +Prepare toolchain (Debian, Ubuntu): ``` sudo apt-get install git wget make libncurses-dev flex bison gperf python python-serial @@ -82,8 +82,9 @@ You would probably have to adapt the `UPLOAD_PORT` in the `Makefile` or set it v ## Battery Life The hardware was designed with two options to drop the battery voltage to a level, which can be fed to the ESP32: A voltage regulator or a simple diode. -A test with increased data rate (for a shorter test duration) showed, that the voltage regulator leads to a slight battery life benefit. +A test with increased data rate (for a shorter test duration) resulted in a slightly better battery life using the voltage regulator. Using a measurement interval of 30 seconds and a WiFi connection interval of 3 minutes, the 2500mAh LiIon (3.7V) battery lasted 30 days with the diode and 36 days using the voltage regulator. +In real-world application, a battery life of about 9 months can be expected (with good WLAN reception). The selected voltage regulator has a quite low drop-out voltage and more importantly a low leaking current during the deep-sleep phases, which have a very low current needed by the ESP32. In comparison a diode has no leaking current at all, but a more or less fixed voltage drop.