Hello Tom R. Thank you for your feedback. We are sorry to hear about the experience you had with the 80V 4Ah battery. Greenworks, renewed 80V battery is backed by a a 90-day warranty. The battery life span will be determined by storage and care which is located inside the owner’s manual. When the battery is not in use, we suggest storing it indoors, in a cool dry area - away from direct sunlight. Leave the charger unplugged and the battery disconnected from the charger unless it needs charging. It is recommended to store the battery at full charge, and if it is being stored for a period where no use is expected, to check on the charge every couple of months. If you notice the charge has dropped, we advise charging the battery back up to full before returning it to its safe storage place. Following these steps will ensure you receive most of the battery life.
Should you have any further questions or warranty needs, contact us through Live Chat on www.greenworkstools.com or call Greenworks Pro toll-free helpline 1-855-345-3934. So, our experts can discuss your experience; please have your unit, battery and charger with you along with the model and serial number to complete troubleshooting to ensure quick resolution is provided.