Display shows E3 and the mower stops or refuses to leave the docking station.

Safety first: Turn the mower OFF and disconnect the docking station from mains power.

• Clean charging contacts: Use a dry cloth or a Scotch-Brite pad to gently clean the metal charging contacts on both the mower and the docking station. Do not use oil or aggressive cleaners.
• Check alignment: Place the mower manually into the docking station. Ensure it slides fully forward and both contacts touch evenly. Adjust the base station position or ground anchors if the mower sits skewed.
• Inspect power supply: Check the low-voltage cable from the power supply to the docking station for cuts, kinks, or crushed sections. Verify the power supply LED is lit when plugged in.
• Check for debris: Remove any grass clippings, leaves, or twigs that may prevent the mower from docking fully.
• Reboot system: With everything clean and aligned, reconnect power, wait 30 seconds, then switch the mower ON and attempt to start a docking/undocking cycle.

If E3 persists, the docking station control board or the mower’s main PCB may have a communication fault and should be diagnosed with Stihl service tools at an authorized dealer.