I am from the great state of Texas, and am building a high power E-Bike. I am going to detail the build in this post hopefully with lots of pictures.
Of course as true with everything else here, Everything is Bigger in Texas, this E-Bike is not an exception.
Coming in with an estimated weight of ~75kg with batteries, the specs for this bike are:
(570) Panasonic NCR18650PF Recieved
(1) Kelly KBL72501E, 72v 500A
Kelly KEB72121E 72v 550A Recieved
(1) Enduro Ebike Frame (Cheap Chinese one with 140mm width) Recieved
(1) QS 273 v3 Hub Motor Recieved
(1) DNM USD-8 Forks
Going to a Marzocchi 380 CR Recieved
(1) RockShox Kage RC Rear Shock
Ended up going with the DNM Burner Recieved
(1) Domino Throttle Recieved
(1) Cheap Thumb Throttle for Regen Recieved
(2) 22" OD Rims and Tires? Recieved
(1) 73Kg Me
In addition to this, I am implementing an arduino based cycle analyst replacement. The CA-V3 seems great but its pricey and I think I could do it better. I am going to be using adafruit neopixels to display power meter in much the same way you see a tesla do so, with a current meter and a orange color during regen. I will also use this with the temperature probes to monitor and display battery, motor, and controller temperature. I couldn't figure out a way to get around floating point calculations in this code (I'm not very good at it) so am using a separate arduino forthrottle filtering
and mapping for separate power levels. Using a digital throttle inhibitor is far to much work for an amateur like myself, and would require a low-pass filter that either introduces inaccuracy or latency, neither are desirable for a throttle response. I will instead use an analog voltage divider circuit for different power levels.
The battery is going to be 560 Panasonic PFs in 20s 28p, to get a peak 20kw. It will be a tight fit, but In a render I was able to get 546 cells in there, and I didn't account for some of the curves on the frame, if I can't fit them all no biggie. Everything I read says these cells can do 10a continuous, but I don't think that would do well so I won't peak over that. I am going to weld 2 layers of 8mm*.1mm nickel strip onto these cells with an arduino built spot welder, as I can't seem to buy a JP Spot Welder anymore. According to posts here that is acceptable for ~10amps, right where I will peak per cell. I am going to use 2 AWG Wire for all the connections between battery/controller/motor up till the closest point on the swingarm.
The QS 273 V3 will require widened and reinforced dropouts which I am going to machine at a local shop. Fun physics tells me that an Approx 350nm (258ft/lbs) of torque with a 22 inch wheel, is theoretically 309lbs of force, or 1375N. Me +the bike will be about 150 kg. 1375/150 ~= 9m/s^2 of acceleration, provided I don't flip over. I am only half way through Physics so if this is wrong feel free to correct me.
As for charging this pack, I realized that even if I only used 4.5kwh per round trip it would still take me 15 hours with a quality 300w charger such as the ones from lunacycle. I have decided to build a meanwell knockoff charger with (7) 12v 30a chargers in series. This should be able to charge the (theoretical) pack in less than 3 hours, or 9 hours at 10a which is a more realistic rating for the cheapo chargers. I only have one on order right now to see if I can figure out how to current limit it as well as disconnected the negative terminal from ground to avoid having them short.
Going with the BMS battery S2500 2100w charger. Even with the $85 shipping (total rip off) it was about the same price as a meanwell abomination + the work required for it. I ordered it with the 240v option.
I will be waiting for batteries for a month at best, so I am going to find a auto battery for me to test my spot welder with.
Once I resize them I will upload them here, but full res images are in this imgur album: http://imgur.com/gallery/myski