So while looking for rear light to go with B+M Luxos U, facing with the lack of post-mount options, I thought, why not make my own?
With no electronics experience, the idea is to piggyback on factory made lights, just to permanently and securely connect them to a power source i.e. the Out ports on the Luxos U via existing USB charging port. If that works it will benefit from hours of stand light with a substantial internal battery. Having read elsewhere here about I think the new multicolour COB leds will be useful in the fog.
A new case may be needed but tempering of the electronics should be largely avoided. Once soldering is done, everything can be encased in epoxy etc (with access to button) to make it watertight. The other end of the cable will be similar to the one from the dynamo to the light, waterproofed with good connectors and heat shrink tubes.
Of course Luxos like most other dynamo lights output 6V to the rear light, while the USB charging is 5V - can the 1V difference be safely ignored - the very cable should probably lower the voltage a bit? Another concern is if the internal battery would age super fast with constant "charge through"
I am quite sure something like this has gone from people's mind here - any advice?