Villiers battery charging system ?

[R]

In the late 40s early 1950s, you could buy a basic little Villiers powered bike with direct AC lighting only.
Or, the upmarket version with 6v battery and charging system.
And the direct AC lighting was still available, selectable on the (special) Miller 4 pole headlamp switch.

I was somewhat bemused to see the battery charging system seemingly has no voltage control (?)
Or have I missed something ?   How did they get away with this ?
Does the half-wave rectified 6v output only constitute a trickle charge to the battery maybe  ?

Does the base model Villiers have the same number of lighting coils for the flywheel as the battery model ?

Jist curious, at this stage ...

[R]

Reading about, it seems that Villiers engines came with 2, 4 or 6 lighting coils.
Mine has 2,  being early postwar.

And the correct bulbs are listed as 1 amp and .75 amp
So the total max lighting output AC  is ~10 w  ?
And a half wave rectifier acting on that would be 5 watts DC for the battery. ?
So literally just a trickle charge.

The plan to just use a 6v battery and charge it occasionally at home seems solid,
its unlikely to get much (ever ?) nighttime use ...