Hello Nelson21.

Thank you for choosing Greenworks for your lawn care needs! We appreciate your feedback and are glad you have some pros and cons to share with us. Tires slipping, can be caused by a combination of factors, including tire condition, ground conditions, and mowing technique. With practice, you can get a feel for how your mower behaves on different terrains and learn to adjust your mowing technique accordingly.
We are sorry to hear you are not happy with the runtime you are getting with the battery included. As we are not sure of the condition of your lawn, we are not exactly sure why the battery did not meet your expectations. The maximum runtime often applies to a relatively flat, open yard. Slopes and obstacles require more power, and users can expect running time to be less, if this is the case. Runtime measurements are also related to the condition of the grass and if it is well-maintained. Tall, thick grass requires more power, and you must mow it slower, consuming added runtime. Here are a few tips to ensure the max runtime is achieved. Ensure you charge the battery fully before each use, maintain the battery properly by cleaning terminals, avoid extreme temperatures during storage. Consider buying a second battery for larger lawns, this mower can be used with Greenworks 80v battery, for optimal runtime we would recommended to use all provided batteries. Mow in a straight line and choose a mower with a powerful battery suitable for your lawn size. If the grass has been left to exceed four inches, we advise that you raise the cutting height and cut no more than one-third of the length of grass at a time, wait a couple of days and do another one-third, cut when grass is dry and walk at steady pace to allow the blade to work more efficiently. As the lawn becomes consistently maintained you will see the cut and runtime improve. Hope these tips help! If you ever have specific questions or concerns about our products, contact Greenworks via Live chat on our website (www.greenworkstools.com), call Greenworks Pro toll-free helpline at 1-855-345-3934 or refer to the FAQ ask section of the tool or ask us a question, anytime.