Hello Notsure.
Thank you for sharing your experience. We understand how frustrating it is when a battery does not deliver the runtime you expect, especially right out of the box. Based on what you described, the red temperature indicator you encountered is typically tied to the battery’s built-in protection system. Lithium-ion batteries are designed to temporarily shut down if they become too warm (or too cold) during use in order to prevent damage, and this can result in shorter initial runtime or the need to let the battery rest before charging again.
There are a few things that may help improve performance moving forward. Ensuring the battery is fully charged and properly seated before use is important, and allowing it to cool to room temperature between heavy use and charging cycles can make a difference. If the battery continues to overheat quickly or only provides very limited runtime after a few cycles, our succrss team can assist with further troubleshooting. They can be reached either using the online chat function, on Greenworks Tools page, accessible by clicking “Chat Now” in the bottom corner of your screen or by calling 1-888-909-6757.