diff --git a/Input-Calibration.md b/Input-Calibration.md
index 5f134fc..af66e5b 100644
--- a/Input-Calibration.md
+++ b/Input-Calibration.md
@@ -91,6 +91,8 @@ It also identifies the type of input and checks if it can be protected (ADC only
 * Release potis to the resting position
 * Press the power button to confirm or wait for the 20 sec timeout
 
+⚠ FOC firmware might not pick up the button press if the voltage is too low.
+
 ### Input type identification
 If you haven't moved one of the inputs, if it's floating or is grounded, it will be identified as inactive and ignored(type=0).<br />
 If min and mid values are close, the inputs will be identified as normal potis(type=1).<br />