Check for obstruction or misalignment in the battery port.
- Inspect the battery terminals and the mower's contact points for dirt, grass clippings, or corrosion. Clean with a dry cloth.
- Ensure the battery is oriented correctly (the Greenworks logo/button usually faces out).
- Insert the battery firmly straight in until it audibly clicks and locks. You should not be able to pull it out without pressing the release button.
IF THAT DIDN'T WORK: The plastic locking latch inside the mower's battery port might be broken or obstructed. Do not force it. This requires service.
HEADS UP: Always store and charge batteries in a dry location. Moisture in the contacts is a common cause of connection issues.