It really depends on your criteria of "flood".
Most of the widest coverage lights I measured were the general type with a hotspot and side-spill/corona -
Probably not the answer you're looking for but the widest "single cell" coverage I got as in these threads -
Light Coverage - spill-diameter Pics
and
Light Coverage - spill-diameter
was actually a Ray-o-Vac floating lantern with the reticulated/orange peel reflector - it managed 122deg which is the coverage of a 12mm lens on a 35mm camera (extremeWide - almost fisheye) using a single lantern cell(!:huh: ).
As examples the measurements I got were (I do realize not all the lights are single cell) -
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All lights with front bezel 12" away from wall
Light/ Diameter/ Angle/ Lens equiv on 35mm camera
Ray-O-Vac Lantern/ 43"/ 122deg/ 12mm (extremeWide - almost fisheye)
Streamlight Scorpion/ 36"/ 113deg/ 14mm (extremeWide)
SureFire 9P/ 26"/ 95deg/ 20mm (ultraWide)
Ultra-G/ 22"/ 85deg/ 24mm (very wide)
Dorcy 1AAA/ 21"/ 82deg/ 25mm (very wide)
ArcAAA/ 15"/ 64deg/ 35mm (semi-wide to normal)
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However for a 1watt Luxeon using a single CR123 cell I really like the inexpensive
S1801 1w Luxeon 1xCR123 - it has a very wide coverage -
but
NOT what I would have called flood type beam - it managed 20.5" diameter at 12" - so using the same calculations as above -
S1801 1w Luxeon 1xCR123 / 20.5" / 81deg / ~25.3mm (very wide)
Fenix L1 v2.5 / 18" / 74deg / 29mm (wide)
MJLED drop-in for MiniMag 2AA / 24" / 90deg / 22mm (very to ultra wide)
- included as a reference - the angle measurements for the regular MiniMag 2AA unmodified with standard incandescent bulb is exactly the same.
I would not regard any of these as true flood lights - just regular type beams with central hotspots but pretty wide side-spill/corona coverage......
Hope some of this helps.