Hello YANHUA,
Thank you for your feedback. We are sorry to hear the charger stopped working after only one use. Before assuming it has failed, here are a few troubleshooting steps that often resolve charging issues:
First, plug the charger directly into a known working wall outlet (avoid extension cords or power strips), and if possible try a different outlet to rule out a tripped breaker or GFCI outlet reset. Next, check the charger indicator lights, if there are no lights at all, unplug the charger for 5 -10 minutes to reset its internal protection circuit, then plug it back in and try again.
Also inspect the battery and charger contacts to ensure they are clean, dry, and fully seated. Even a slight misalignment can prevent charging. If you have another compatible battery, test the charger with it to determine whether the issue is with the battery or charger. Likewise, test your battery in a different compatible charger if available.
Make sure the battery is not too hot or too cold, as temperature protection can temporarily prevent charging until it returns to room temperature. Finally, inspect the power cord for any visible damage or kinks.
If none of these steps restore normal operation, werecommend contacting our customer support team for assistance with properly submitting a warranty claim. They can be reached either using the online chat function, on Greenworks Tools page, or by calling 1-888-909-6757.