The 4 Ah battery quit and was flashing red and then off. According to what I read on posts, it was remotely possible that the battery overheated even though it was a cool day and I was not using the leaf blower on the turbo setting until it "failed" and shut off the blower. It would not charge, flashed red and then showed a full charge. The next day, I put it in the refridgerator for 2 hours at 34 degrees F. Then it charged normally to a full charge and the "malfunction" disappeared. The battery is a little over 3 years old and I have always kept it fully charged, take it off the charger when charged and placed it on a shelf in the basement. It appears that I just saved between $206 and $239 for a new battery! I hope this will help someone else with the same problem. I will update this post if the battery fails again.