You need lots of lumens for daytime visibility. IMO no AA or AAA light is going to be particularly visible.
Years ago I had a motorcycle totaled out from under me on a bright daylight day and it had the headlight on and a headlight modulator installed for daylight visibility. I was running a H4 halogen headlight bulb with 40 watts low beam power draw, far more than any bicycle light made. I swear the gal looked right at me before turning in front of me. She still told the cop that she never saw me. She was not looking for a motorcycle so I never registered on her conscious brain.
Even with a daytime light you need to ride like you are invisible to auto drivers.
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Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
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