Seen one or two a while back but havn't seen any for a while.
Personally, i have seen some what appears to be ridiculous conversions, massive motors, 48v batteries that claim 30mph plus but it seems a bit shortsighted if a buyer doesnt realise the drain that is going to have on the battery...or the time such a big battery is going to need to recharge...and the lifespan of said battery is surely going to be significantly shorter...and very expensive to replace.
Seems to me people just see the extra speed benefit, but the drawbacks look significant.
Voltage is not a indicator of power. Only when current and voltage are multipled to give power capabilities.
Using a higher voltage reduces current demand to give the same power, thus reducing heat build up in the Motor windings
Batteries will last along time if you care for them and dont overcharge or run flat
My battery is protected by minimum voltage on the controller, so the system will shut down before batteries get too low
I use a 52V battery and use open software to tweak the motor power delivery for increased range. I have limited max current availability to the motor drive thus keeping temperature in control.
Dont get me wrong, if I were to stupid, I could set the motor to run at 750W constant and at speed over 25 mph- I dont.
It allows my wife to do long rides upto 50 miles at my pace which averages out around 14 mph. She can however destroy me on any incline by selecting a higher power setting. Her bike is a shopper with panniers, full time dynamo lights, we carry picnics, chairs when going for a ride out.
Folks can use ebikes with responsible attitudes