Bafang BB02, 36 volt, 500 watt, e-bike.

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Aug 20, 2009
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494
Location
Erie, PA.
I was looking at a bunch of mid drive motor set ups and I finally decided to try the Bafang BB02. The geared motor, controller, and bottom bracket crank set come as a unit and slide into the bottom bracket. Slide might be an exaggeration. Mine required a little work with a file to enlarge the bracket slightly and I also sanded the paint off the part that fits into the BB to get it to fit. The 'throttle' is basically an on-off switch and there are 3 levels of assist. The speed at each level is: 1. 18kph-11mph, 2. 22kph-13.6mph, 3. 32kph-19.8mph. These speeds meet the federal limit of 20mph and the speed is limited electrically. The motor accelerates very briskly up to the limit and I'm sure if the governor could be bypassed/eliminated the moter is capable of at least 30mph. The earlier Bafang BB01 was a 250 watt unit, primarily designed to meet Europe's very low limit for e-bikes. The newer BB02 is available in 36 and 48 volts and up to 750 watts. The 500 watt unit I got is about 2/3 horse power, and seems very adequate. The only changes I would like to see is a analog throttle and an electrically governed speed limit that could be adjusted higher, to at least 25mph. The quality of the unit/components seems to be of a high level and I am very satisfied. I orderede the unit from tnabattery-ebike in China and paid for it through paypal. the shipping via DHL was about $80.00 US and delivery was timely, if not quick. The only piece missing was the magnet for the speed control/consol. No big deal as I had several from old Catseye speedos and they work fine. Everything was packed well and nothing broke in shipment, though the box was slightly smuched. The Bafang unit is installed on my old e-bike that was powered by an e-bikekit direct drive hubmotor with a dead controller. It has better acceleration and is lighter than the old hub motor. 001.jpg002.jpg003.jpg004.jpg
 
Cool. Do you think the bottom bracket mounted motor is worth the extra installation effort over a hub motor? What type of battery pack are you running with the Bafang motor?
 
The installation was quite easy, once I found the instruction video on youtube. The acceleration is much better than with a hub motor, and, since the motor drives through the bike chain, hill climbing is easy since you are using the bike's gears. If you are running a bike with only a single speed, then the hub motor would be simpler than a mid-mounted motor. I haven't had this Bafang unit long enough to have done a range test, I can't vouch for it, but there seems to be a general consensus that the mid-mount e-bikes should get more range per charge on the battery. I'll post about that, once I have done a long range test.

I am using a LiFePo4(Lithium-Iron-Phosphate) 36 volt, 20amphour battery from Ping Battery. I would get 35 miles per charge with a 9 Continents direct drive hub motor from e-bikekits.com.
 
It is very flat where I live, but it's not unusual to face a 25mph headwind on the commute home from work. I deplete my 24v batteries pretty quick against those headwinds.
 
Battery voltage is what makes speed. The direct drive hub motors/controllers I used before could use 36 or 48 volt batteries and, with a different controller, the motors could handle up to 96 volts. Each step up in voltage meant an increase in speed. Mine ran 22mph on 36 volts and 28mph on a 48 volt battery. The range(distance you can travel on a single full charge) is determined by the amp-hours of the battery. I could go 35 miles per charge on a 36 volt, 20 amp-hour battery, and 28 miles on a 48 volt, 15 amp-hour battery. One advantage to a center drive motor is you could gear down in a head wind, or going up a hill. It does take more battery amps to run geared down, but much much more battery running full throttle lugging down a motor under full load. It will draw max amps trying to get up to speed, pulling down the battery. Watts are a measure of work(horse power), volts are the driving force, sort of like pressure in a hose(PSI), amps are the volume of electricity being used, like the volume of water flowing in a hose(gallons per hour). Watts = amps X volts.
 
I discovered something new about the Bafang last weekend. If I turn on the unit electrically, but leave the throttle off, the unit will assist as I pedal. I didn't realize that until I stumbled upon it by accident.
 
Best way to go is simple front hub for mainly street trail and climbing a rear hub motor setup. Clean, fast and it works!
 
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