Treks Removable Integrated Battery-System looks good and is user-friendly: it is fully integrated into the frame, well-protected, easy to remove without tools, and even has space for a water bottle holder. This bike expands horizons: the top-notch Bosch system is equally suitable for daily commuting, leisure rides, and great times on the trails. The Purion controller features a Walk Assist function and an intelligent eMTB mode that automatically provides the needed power depending on the terrain. Thanks to the external charging port, you can easily and conveniently charge the battery while it is in the frame or removed.