Robot mower will not start mowing; display shows E01 immediately after power‑on or when starting a job.

Safety first: Power the Yarbo robot mower OFF using the main power switch and remove it from the lawn. Do not work on the unit while it is wet or charging.

• Check battery charge level: Place the mower on its Yarbo charging dock and verify that the charging indicator on the mower and dock are lit. Allow at least 2–3 hours of uninterrupted charging, then try to start a mowing cycle again.
• Inspect battery connectors: With the unit powered OFF, open the battery compartment (usually under the top service cover). Visually inspect the Li‑ion battery pack connector and the mating plug on the main control board for corrosion, bent pins, or looseness. Reseat the connector firmly.
• Cold‑weather lockout: If ambient temperature is near or below freezing, move the mower and dock indoors to a dry area (10–30°C) for several hours, then attempt charging and starting again. Low temperature can trigger undervoltage protection.
• Check for swollen or damaged pack: If the battery pack appears swollen, leaking, or has a burnt smell, do not use it. Disconnect it and replace it with a compatible Yarbo Li‑ion battery pack.

If E01 persists after a full charge and connector inspection, the internal BMS or cells are likely faulty and the battery pack should be replaced.