The UL listing is for the PECC or Enersection as it's now called. UL certificate is required for devices that connect to the grid-not the battery. One important role of which is to prevent the system from back feeding into the power grid during an outage and electrocuting repair people. There was a poster, Loama319, a while back that pointed out that UL certification is not needed when the device is located behind the fence. The fence could refer to substations, power generation station, oil platforms, etc. Thus, power cube won't need UL for these applications. Unfortunately, ZBB's high powered Enersection models are just starting the UL process-although is should be much faster given that they are based upon the low power model. So in situations where another battery manufacturer needs a UL approved unit, ZBB is there to provide a battery agnostic inverter/controller solution. Battery agnostic is the key word as different storage situations dictate a variety of batteries depending upon the desired characteristics.