diff --git a/README.md b/README.md
index 7399e1a..7206ab6 100644
--- a/README.md
+++ b/README.md
@@ -202,6 +202,15 @@ the following libraries:
 - [NimBLE-Arduino](https://github.com/h2zero/NimBLE-Arduino)
 - [TinyGPSPlus](https://github.com/mikalhart/TinyGPSPlus)
 
+# Known Issues
+- depending on your perspective, battery life is anywhere from reasonable to abysmal
+   - with an active BLE connection, the ESP32 consumes around 50mA
+      - an M5StickC Plus2 would last around 4 hours
+      - an M5StickC Plus would last around 2.5 hours
+      - an old M5StickC would last less than 2 hours
+   - if battery life is crucial, and form factor is not, consider an M5Stack Core2 with the 1500mAh module
+      - this might last 30 hours
+
 # Things To Do
 - error handling is atrocious (it'll probably crash, then restart, which is OK,
   the M5StickC boots quickly)