battery backup easily replaceable electronics reduced operating and ownership costs reduced heat output greatly reduced electrical power cost to operate for same luminous flux increased comfort level no or little hazardous material no light or dark spots more consistent light quality over time and simplified relocation over conventional fluorescent lighting fixtures an embodiment of the present invention advantageously provides for integral and automatic battery backup in the event primary power is lost an embodiment of the present invention also provides for a sealed battery powered led based mobile lighting fixture that can be used in wet moist or potentially explosive locations in one embodiment as illustrated in fig1 cool tube u2122 led technology includes a light fixture module consisting of an extruded aluminum core 100 containing an integral heat sink 110 multiple linear arrays of leds 200 with an attached light diffuser 300 the light diffuser shape 310 internal surface treatment 320 and external surface treatment 330 are optimized to maximize light transfer efficiency from the led arrays to the tube 39 s exit radiation cone diffuser surface treatments include but are not limited to mico lens embossing and prism light guiding plate in combination with an optical film u201c trt u201d as described in u s patent application publication serial no 2006 0268418 entitled method of making and using optical films to kim u s patent application ser no 11 417 172 the diffuser 300 is sealed 340 to the core 100 an extruded aluminum core is preferred over a core manufactured using other processes such as aluminum casting because of the.