This peak racing power plant 4000 mah 3S 11.1 volt lipo battery features a hard shell battery case which is essential for safety purposes so the battery cannot be easily punctured. These batteries feature high-quality cells to ensure the best possible performance and long life. Equipped with "Deans" style connectors and a balance port to ensure the most complete and safest charging, these batteries have been the choice of experienced enthusiasts who value quality and understand that the cheapest battery isn't always a wise investment. The peak racing line of lipo batteries are among the best available for just about any RC car, ranging from the "fun" class of products, up to the more serious performance machines that need the extra power capacity needed for RC vehicles with powerful motors. Cheap batteries often have lower overall power output, which means that the lower price you paid will limit the acceleration and top speed in the applications where more battery power is needed to feed the motor for maximum performance.