Hello Robert5832.
We are sorry to hear you are experiencing shorter-than-expected runtime with your blower. On high speed (non-turbo), runtime can vary depending on conditions such as debris load, temperature, and battery condition, but consistently dropping to around 15 minutes may indicate something worth checking. We recommend first ensuring the battery is fully charged using the included charger until the indicator shows a complete charge, and confirming the battery contacts are clean and fully seated. It can also help to test the unit in different speed settings, as continuous high-speed use will significantly reduce runtime compared to lower settings. If the issue continues after a full charge cycle and normal use conditions, the battery may require inspection. For further assistance and diagnostics, the Greenworks Tools customer succes team can help review your setup and determine the best next step. They can be reached either using the online chat function, on Greenworks Tools page, or by calling 1-888-909-6757.