The 11 and 13 foot Bliss Mobil units come with a single battery pack as standard. If your unit has the right layout, an additional 400Ah/24VDC battery pack can be placed in the seating area underneath the couch. Placing a second battery pack effectively doubles your battery capacity to 800Ah or >20kWh, increasing the potential of your electrical system even further. 

Since the battery pack is a fully independent functioning pack with its own completely independent functioning Battery Management System, it also offers redundancy in case of unexpected and highly unlikely failure of one of the battery packs.