Other than halogen lamps, LEDs are highly effective even at low power, i.e. when run below the nominal power/ its rated capacity. This is the reason why dynamos no longer need to be build in a way for them to reach full power at the lowest possible speed. Therefore, SONdelux is smaller and lighter than a hub dynamo for halogen lighting (SON 28).
No-load power input drops by about 30 - 35% compared to SON 28. But SONdelux equals SON 28 concerning durability and outstanding quality.
Unfortunately includes only the SON28 and SON20 and not the SONdelux.