We have a customer who owns a series of 24 and 30 unit apartment buildings. Presently on each floor as per local requirements thereare several self contained emergency lighting units. Some of these are equipped with a small 6V battery and just two low voltage lamps that aim in different directions down the hallway, while other larger units having larger batteries sometimes might have as many as six 12volt lamps wired remotely. These all are equipped with sealed lead acid rechargeable batteries which need to be replaced every few years. Two of his buildings are exceptions though and don’t have this type of lighting. In these buildings, the hallway lighting circuit is wired through an inverter system. This system, which was built by a company in Massachusetts many years ago is installed in the boiler/electrical room, and consists of two 12VDC to 120VAC 450W solid state inverters operating in parallel and two group 24 size wet cell automotive batteries. There is a built in charger and a huge contactor which drops out upon loss of AC and applies 12VDC to the inverters. Loss of AC will cause the load to toggle over to the inverter outputs and the hallway lighting circuit remains powered. Maintenance on these two buildings is minimal and his ultimate cost savings projection becomes significant when multiplying installing this type of system into the 100’s of buildings which he presently owns. He has asked me to look into finding this type of equipment for him to retrofit his other buildings. The typical load is about 400W CFL and will probably never exceed 550W. I don’t know how picky these particular 13W CFL units are to anything other than sine wave AC. I know sine wave or even modified sine wave will probably increase cost somewhat. Does anyone have any ideas for inverter systems equipment they might be able to share with me? Thanks, Lenny.