diff --git a/README.md b/README.md
index b2404b0b2..a916b8f3a 100644
--- a/README.md
+++ b/README.md
@@ -201,6 +201,13 @@ Libraries that don't rely on low-level access to AVR registers should work well.
 Pick the correct serial port.
 You need to put ESP8266 into bootloader mode before uploading code.
 
+#### Power Supply ####
+
+For stable use of the ESP8266 a power supply with 3V3 and >= 250mA is required.
+
+* Note
+ - using Power from USB to Serial is may unstable, they not deliver enough current. 
+ 
 #### Minimal hardware Setup for Bootloading and usage ####
 
 ESPxx Hardware
diff --git a/doc/ESP_to_serial.png b/doc/ESP_to_serial.png
index 2d09ce076..9dd116be7 100644
Binary files a/doc/ESP_to_serial.png and b/doc/ESP_to_serial.png differ