Originally Posted by
elcyc
The dynamo could be intelligently integrated into the braking system somehow ... say every time you squeezed brakes, or were coasting downhill. The "braking" load, experienced with a typical hub dynamo, from powering a phone or lights, could be used to recharge the drive-motor battery. Effectively: DIY regenerative braking ... until the all-in-one units (found in cars and locomotives) are a cost-effective option for eBikes. That's something Tesla should look into ... instead of wasting $$ with hyperloops and launching cars into orbit.
This is exactly how regen systems work now. In the brakes are switches that sense when they are touched. Not hard enough to actually apply the brakes but to switch on the regen system. But there is never any 'free lunch'. It is about a 10:1 loss at present levels of the technology. You get 10% of the energy it took to climb a hill when you regen back down. You will NEVER break even. Overnight charging of the big battery mounted on the downtube will be the go to charging paradigm for a long time to come.
But, wait, it gets better ... if you continually charge your battery to 100% overnight and run it right down the next day, your battery will need replacement in as short as two years. If you never charge it more than 80% and never run it down below 20%, the same battery could last 5 years. So, buy the biggest battery you can afford and never use more than 60% of it's potential.