d8veh,d8veh wrote:I'm not too sure where that figure comes from, but when I rode a bike with the Ananda crank-drive, it wasn't more powerful than the 250w Bafang CD., which means gutless!t3sla wrote: For contrast the Ananda mid drive systems does 100N.m, with only 5A......dat gearing!
The TMC unit is similar to the Bafang one. It has about the same power(riding experience). I increased the current from rhe standard 15 amps to 24 amps, but it didn't make much difference to performance. It just made the motor get hotter.mwkeefer wrote:jk1,
If I can increase current by 1/3 maximum and nominal it would produce 638w at 16.88 A and 48.13v by adding a shunt and increase the maximum to perhaps 22.45A as main battery maximum current for a total at 48v of 1082.925 watts and 68.15 ft lbs of torque.
Based on your description / experience it sounds like somewhere between the two values there simply isn't enough mass or copper and the eddy currents begin to flow making a wonderful heater? I think my default on this is 16.8A with maximum of 17.08A. Using a piece of excercise equipment late at night and dialing up the resistance will alllow me to test with 1A increment at a time to find the absolute sweet spot between performance, economy and top speed.
I must ask how did you increase your current, if they are similar (or copies) then the controller is inside the drive? Just curious
I was thinking about this - it seems current wise this motor is just below saturation at 17.08 A Stock and want's 13S Lipo or 48v nominal to attain 88 RPM at the crank.
Unloaded @ .83A and 112.2 RPM
Max efficiency should be 82.6 @ 10.37A @ 413 watts and 37.1 NM Torque or 327.48 in lbs or 27.29 ft lbs
(*** This is equal or exceedings the torque provided by a stock 9C front hub with 36v and 22A Infineon Controller)
Max power should be at 638w or 16.88 A and produce 68.7 N.m. or 50.670519655329905 ft lbs.
Max torque will be at 554.19w or 17.08A and would be equal to 90 N.m. or 66.38059343493 ft lbs
(*** This maximum torque is 10 Nm higher than even the bosch drive system and with I believe a retail between 600 and 800.00 depending on parts included and longevity of the product - well that is seriously on par with hub motors but I've got a few hills most people walk up with their bikes...
Please feel free to examine my numbers, without replacing the stock controller or beefing it up I wouldn't exceed 15S or 55.5v nominal or 61.875 hot off the charger, it works with most stock controllers and should work with this one too... wish I could adjust the voltage divider but.. I can try it at 15S and pray the caps are 63v.
If anyone has gotten this model apart yet, please let me know the process please
BTW: Once I'm done testing this unlimited (no speed limit, throttle not linked directly to pedalec, works independent) on a bike or two I will be receiving my own sample units, 2 of each including the tool and programming adapter and software so I can configure these with physical speed limits, etc - They will be available for 36v and 48v but I will only stock a few until the 750w unit comes out and is made available through import channels.
This sample unit will be available within about a week (mostly bench testing, probably put about 10 miles on road tests) and I won't be testing at 18S due to the likely 63v caps... I will be offering it along for my cost (it wasn't cheap) + postage (Likely around $13-$18.00 priority mail. PM me if your interested the price I paid was $650.00 USD, first come first serve order
To be perfectly honest:
I just couldn't wait to test the units Ive already ordered for samples, they take weeks - this was available in the USA and with EMS shipping from china it's exactly what sample units would cost in single units, so for anyone else wishing to evaluate the Bafang Bottom Bracket 350w drive with LCD Control Dash, Internal Controller, 48.1v nominal pack - which provides 88 RPM loaded at the torque specified above or elsewhere but peaking at 90 N.m. on the stock controller with 48v at 17.08A and outputting 504 watts in stock format with the internal controller... that's pretty strong (stronger than the bosch and many other mid drive kits) and with the rear derailleur setup for 7 speeds (stronger chain) and tuned index shifters - this thing should be able to climb just about any mountain in the proper gear.
I can wait to punish a setup on the road when I get my own samples and can program the on board controller - (I do want to test any temp difference between having the controller onboard vs external lyen or methods or ecrazyman or sensorless RC controller like ICE HV40 - it may be a way to squeeze a few more amps in without generating as much heat.within the motor casing.