This 72V Battery bag has enough space to hold 6 12V 18Ah SLA Batteries. There are three compartments that have reinforced openings to the different compartments that allow ease of wiring the batteries between the compartments. The bag can be mounted on a rear bike rack. The bag comes with Velcro straps for securing the bag to the rear rack.  This bag is a must for larger batteries for extended range or for voltages greater than 48V.