I like my B&M 4D senso.. 2AA, use what battery you like. German, rack mount.

Only blinks in tunnel mode .ie On but light sensor leaves it off, in senso mode, but enter a dark tunnel it blinks .

then off again in daylight. at night in that mode motion sensor turns it on , then off again when you have stopped
for more time than if lust at a stoplight.

Features a 3 position switch .. Off - On - and senso. B&M 4D senso Plus runs off the hub dynamo in the off mode
but goes off when I stop, (unlike newer lights with the capacitor stand lights)

so running in the daylight it just uses the Battery in the On Position
whether the Plus or not.. the 4D 'permanent' is on/off.