Ive been working on my own custom built ebike for a few months now..
I hear stories and see advertisements for ebikes which can go upto 50KM on one charge.
I'm currently using a custom built 72V 18AH pack.. (the pack is only designed for short bursts of high 20 amps)
thats a peak performance of 1440W with a crystalite hub motor and a 20 Amp controller.
I hooked up an AMP meter to it one day.. going up a fairly steep hill... and noticed needle on the amp meter pretty much hit max 20 AMPS.
although my battery pack can burst 20AMPs for a few seconds it cant sustain that without shortening the capacity of the batteries.
I'm curious to see what peoples opinions about Hub Motors and hills are.
I live in a rather hilly area.. and my pack can only last about 9KM with peddle assist. for a ride which is generally up hill... a very gradual climb.. with a few very steep hills in between.
Am I better off Splitting the pack in 2 and giving it twice as much amp capacity and 36V...
I was thinking of making a switch.. which could switch from 72V down to 36V on hill climbs.
Does anyone know what the peak speed of 36V is with 16inch wheels?
Has anyone done this ?
I know that Chain drive motors have the advantage over hub motors on hills.. but they are also generally less efficient on flat and make a lot more noise.
Ideally if my pack was made up of high drain batteries and I rode the ebike on a flat surface with little to know wind resistance.. then I should be able to ride for an hour on a single charge..
but still going only 20-30 KM an hour thats only 20 - 30 KM..
I just don't see how mathematically any ebike can range up to 50KM unless its going down hill with a fit rider OR it has a 40AH battery pack.
a 60-72V 40AH battery pack using NiMh would be the size of a small suitcase..the kind that might hold a laptop.
with Li-Po it would be about half the size and half - 1/3 the weight.. and of course double the cost.
and I dont see how its possible with SLA batteries as that kind of capacity would break all the spokes on your back wheel.
any thoughts ?