- Mar 19, 2018
I wonder if your thing about the front wheel locking up from the regen in a big concern. I think a lot of other ppl do it and i havent heard that much about this issue. I believe you dont need to worry about backcurrent because there are stud diodes in the controller to prevent any backflow i think. What u need to worry about is i just found out that buying off alibaba is a pita. I was looking at shipping costs and see u have to find a shipping company and get quotes and the lowest i could find was $400 to ship this $100 ebike kit to the USA from jinsuang china. And by boat it was like $1000 because off tarriffs and import fees and customs bonds and all this sh*t. like wtf y so much money!!!! See Alibaba only works if u are buying enough to fill a shipping container. I was thinking abut mass producing these bikes in scale as a side job and now i am a little upset b/c amazon prices are a lot higher and i know that by running it through the rear wheel, thats extra time and sometimes the gear shifter and the gear cassettes don't work perfectly ie a 6speed cassette and 7 speed shifter could make a disaster if you put it in 7 at x speed.You were right actually. It was well worth checking out the Hobby King packs made for remote control devices, "drones" and r/c cars and helicopters etc. The 44,4v nominal that you get when running four of their 11.1v in series is not less real world voltage than a 48v Li-ion battery on most Ebikes, because of the high "C rating" these packs don't suffer from voltage sag when heavily loaded. On my little "250w" overvolted and 333w continuous the peak watt usage would be only barely into the figures where the high Court rating makes a big difference. On the popular 1-3kw motors that are popular in the USA the lithium polymer packs have significant advantages.
The rate of voltage drop as you use up the usable voltage of the battery is different too. The Li-poly has a higher voltage when it is "empty" so actually it's average voltage is about the same as the Li-ion which begins with a higher voltage and ends with lower.
But then there are some other considerations. If you are a beginner and you read the posts about living with these batteries it does come across that everyone is getting through multiple chargers and power supplies before they find one that lasts a while, but not forever. There seems to be no charging system that is guaranteed to work for everyone all the time. Even if you make a list of the choices that other builders finally settled on, there's someone else saying that didn't work for them. There's no consistency, no consensus to follow so you can just buy once and have reliability.
They recharge quickly but..
The batteries and chargers and power supplies should be placed in a fireplace during the charge process and must be monitored.
You have to carry a pair of server power supplies and a very large charger and the battery medic etc if you are going on a road trip. Not like the compact little chargers used for the common Li-ion "ebike" batteries.
So for me, for touring and fishing expeditions, I don't think that Li-poly is a practicable option. I need to be able to carry a small charger or two in my panniers, with a campsite electric hook up (or whatever you call them there, RV mains plug and cable), and charge my battery inside my highly flammable tent whole I sleep or on my gasoline loaded bicycle.
But I'm glad I had a look at these. They do look nice and compact and good for high power "sport" ebiking near to home.
But good luck with your build. The only real issues i think of like the ppl who buy a 3000w cyclone kit and have a 48v 20ah battery. The battery can only provide 1000w peak so u are only getting 1/3 of the motors potential or 1/3 the top speed.