Energizer 500W InverterThe most interesting aspect of this inverter is that it has a pair of USB ports. After reading more about it, it appears to be 2.1A shared between the 2 ports and is advertised as being iPad compatible. I know that my BlackBerry 9900 is a finicky smartphone that can only be charged using the included BlackBerry charger, Samsung S3 charger, PowerGen, or Motorola Droid2 chargers from my experience. The BB 9900 will not take a charge from any Belkin charger even if it is rated at 1A, 2A, etc... So I always include the BB 9900 in my charger tests.This Energizer inverter will not charge the BlackBerry using the USB port, although if you plug a charger into the A/C socket it could probably do it. The inverter's USB ports also charge my Samsung Galaxy S3 in USB mode, which means it isn't wired properly to charge in AC mode. My PowerGen and Belkin car chargers all charge the S3 in AC mode, so Energizer should have fixed that in their inverter from the get-go. The USB charging mode is limited in current output, while the AC charging mode is the full 1A current output that most adapters provide.The inverter only operates in 100W mode when plugged in via the cigarette lighter, mainly because most lighters are fused/rated for 10A-12A operation which at 13.2 VDC, ranges from 132-160W maximum and it is a safer idea to de-rate that down to approximately 100W. In order to get the full 500W capability, the Energizer inverter has to be clamped directly to the car's battery terminals. Energizer includes brackets and screws that could be used to permanently install the inverter somewhere in your vehicle. For example, a RV or camper with an auxiliary battery where you could tap into the inverter at your convenience.This inverter is also SIGNIFICANTLY larger than other typical inverters. It's about 2-3 times as thick which makes it bulky to pack.Overall: 4/5 stars, it would be 5 stars if Energizer fixed the USB ports so they would charge smartphones in AC mode as well as charge up some of the picky smartphones like the BB 9900.