What is the run time on the DEWALT® DCST970 Grass Trimmer? Wilson November 17, 2020 19:02 Updated Follow Using the DCB609 FlexVolt battery, you will get about 30 minutes on high speed, and 60 minutes on low speed with the DCST970 trimmer. There are other variables that may affect run time such as weather, humidity, and of course type of grass cutting. Related articles Which DEWALT String Trimmers will the DWO1DT995 QuickLoad work on? Which one does the Spool work on? Comments 0 comments Please sign in to leave a comment.