Bafang E-bike Conversion Kit Design Deficiency

Its been about a year since I built my Bafang conversion e-bike and I still enjoy riding the bike. I am impressed with how powerful the 750 watt motor is and the range the 840wh battery provides. However, the Bafang conversion is missing one key feature that I’ve become very used to on my Bosch e-bike. That is a continuous range estimate on the control display. Without a range estimate provided by the e-bike system, you have to guess the range left in the battery based on your experience.

So it finally happened. I ran out of juice while riding the Bafang. I must admit it came as a surprise. I started the ride with 3 out of 5 bars displayed on the battery indicator. Three out of 5 bars means I should have somewhere between 40-60% of the battery’s charge left. However, after about a mile into my ride the battery dropped to 2 out of 5 bars meaning I had a 40% charge. Still, I wasn’t worried sine I was planning an out and back ride. I simply planned to turn around when, or before, I reached 1 bar. My plan was to use 1 bar going out and 1 bar to return. However things didn’t go as planned.

To my surprise, about 10 miles (16 km) out while climbing a hill the battery dropped to 1 bar. Only 10 miles (16km) on 1 bar? That was unusual. Still I wasn’t worried. I just turned around and headed home. If I used 1 bar going out the remaining bar should get me home. Right? Wrong! Only a few miles more while climbing a short steep hill the battery indicator started flashing empty. No way! I should get more than 15 miles (24 km) on a battery that was at least 40% charged when I started. Was the Battery Management System saving power to protect the battery from completely discharging? There was no way to tell. Not willing to take a chance on damaging my battery, I shut off the power and started pedaling my dead e-bike home unassisted. Luckily it wasn’t as hard as I expected. The motor didn’t add much drag and the additional weight was only noticeable on climbs. About half way home I turned on the system again. What was happening? The display showed 1 bar again and I was able to make it home on assistance level 1. In my opinion, not having a continuous range estimate is a BIG DESIGN DEFICIENCY in the Bafang system, especially when for some unknown reason the first half of a charged battery provides a lot more miles than the last half of the charge.

Ken Whittaker


How to program the Bafang BBS02 Controller

As I mentioned in my post Thumbs Up to Bafang!, one of the outstanding features of the Banfang BBS02 conversion kit is that it’s configurable by the user. Many changes like configuring the bike as a class 1, 2, or 3 and other basic features of the bike can easily be configured from the display.  However, with a laptop computer, a special USB programing cable and the Bafang Configuration Tool Software the Bafang motor controller can also be reprogramed by the user  to  improve the usability and performance of the e-bike.

My goal here is to only make you aware of the possibility of reprogramming capabilities of the Bafang controller.  Detailed instructions can  be found from other sources below:

  • However, be warned that reprogramming your Bafang system is not without risk. You can destroy the controller if done incorrectly.  So, read the guides  and do not attempt to customize your settings if you don’t fully understand what you are doing.  Proceed at your own risk.

Ken Whittaker


Build or Buy an E-bike?

Have you every wonder if it would be better to buy or build an e-bike? I have. So I built an e-bike using an old Cannondale road bike and a Bafang conversion kit. After I was done building the conversion bike, I used the lessons I learned to buy the most cost effective high quality e-bike that I could find at the time. Here are the results.

Cannondale Road Bike Conversion to E-bike with Bafang Kit

Conversion Kit

Motor: Bafang 750 watts

Class: Configurable as a class 1, 2, or 3

Battery: 840Watt Hour

Chainring: 1X 52T

Display: Bafang C961 LCD Display

Cost: $1,100 + Cost of Bicycle

Pros:

Prices – A Bafang conversion is a fraction of the cost even if a new bike is purchased for the conversion

Configurability – The Bafang can be configured as a class 1, 2, or 3 e-bike.

Power: The Bafang has a much larger motor and battery.

Factory Built Cannondale Synapse Neo 1 E-bike with Bosch Motor and Battery

Factory Built

Motor: Bosch Active Line Plus 350W

Class: Class 3 e-bike

Battery: 500Watt Hour Bosch PowerTube

Chainring: 2X 50/34T

Display: Bosch Purion

Cost: $3,799 – MSRP $4,725

Pros:

Gearing – The 2X Chainring with a 50/34T is a game changer for me. It gives a wide range of gears like my traditional bicycle.

Quality – The bike is designed as a system and fits seamlessly together.

Appearance – Likes likes a traditional bike.

Final Analysis: I’ve put hundreds of mile on both bikes and both are great e-bikes. So let your budget be your guide. The Bafang kit is very affordable but does need a little tinkering once in a while. The Cannondale Synapse Neo 1 with its Bosch system is a quality e-bike but considerably more expensive. In retrospect I should have used a bike with wider tires and disc brakes for the Bafang build considering its power, weight and speed.

Ken Whittaker