Just for everyone's information and enjoyment I just finished converting may older Bacchetta Giro 20 recumbent to an Ebike version. Purchased the Bafang BBS02B kit a couple months ago. For the most part installation went pretty smoothly. I had to lengthen the battery power cable that came with the kit. Extender cables are available but cutting the cable and extending it was very easy. I ended up having to make a anti-rotation stop near the bottom bracket so that the motor would not rotate upwards due to the tremendous torque produced. You just can't tighten the nut on the bottom bracket enough to keep the motor from rotating. On a conventional bike this rotation is inhibited by the up tube between the bottom bracket and the head tube. The piece of 1.5 x 0.5 inch aluminum made a good mounting point for the headlight. The kit came with a very nice pannier rack with a battery compartment built in. So far so good. Getting about 40 miles/charge from the 750Wh battery.
CMac
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I like the conversion, especially the torque bar and the way you attached the headlight.
Thanks. I had seen on this forum some photos of people making a bracket that mounts to the bolts on the motor and then clamped to the main tube. The bar was a bit less effort and seems to work well. I should also mention that I had to lengthen the speed sensor cable because I decided to mount it on the rear wheel instead of the front.
Not really. The kit I bought from Amazon had everything necessary except for a power cable extension for the rear rack mounted battery and the speed sensor (I mounted it on the rear wheel). You'll have to make some sort of motor stop to keep the motor from rotating. The large amount of torque produced from the motor makes it impossible to tighten the bottom bracket nut enough to keep the motor from rotating. You can let the motor rotate up to the post that used to hold the front derailleur but then the motor wires will be facing forward as you ride. Best to have them come out underneath the motor. Good Luck and enjoy.
Installed a Bafang BBS02 750w,48v 20.3AH whale shark battery, DPC-18LCD display Set the display on 0-9 rode 41 miles in #4 started with 52.6 volts ended with 52.2. Will check mileage in a higher setting next time,do you know what voltage the motor shuts off?
Just saw your post from a month ago. Most batteries have a BLM that will shut them off automatically when the voltage gets down to a preset level. The BBS02 controller can also monitor the voltage and shut the battery down. The default value for a 48V system is 41V. However if you get the programming cable and software you can change this to suit your needs. I am attaching a PDF from Karl Gesslien at ElectricBike-Blog.com that describes how to program the BBS02 controller. BTW, the voltage you measure must be under load. A 48V system may read 52.6V when you are not riding but it will drop as soon as the battery has to put out current to the motor. As with all batteries as they discharge the voltage will drop under load. The ability of the batter to put out the necessary current to keep up a given speed will decrease as the battery drains. Once the battery voltage gets down to a preset voltage under the load conditions it will shut down.
After a few more rides the battery shut down in the middle of a ride with the voltage reading 52volts. The battery finally quit and wouldn't even charge up. Tried shipping it back but couldn't find anybody to ship the battery. Disassembled the battery and found one cell having a dark end and a voltage reading of .86 volts and the other six in parallel reading 1.1volts. The remaining 84 cell read 4.2volts One bad cell had ruined the whole battery pack. Samsung 18650-29ea cells.
That's unfortunate. I don't have the same battery pack. Where did you get your kit? If you bought it directly from Bafang USA they won't take the battery back. Their stuff is supposed to be warrantied for 90 days however they will not accept returns on batteries. Batteries are the biggest headache when it comes to ebikes. They're usually 1/2 to 3/4 the cost of the system and as you found out 1 bad cell or poor connection between the battery terminals can bring the whole thing down. I'm an electrical engineer so I wouldn't hesitate to repair the battery pack myself if I could get the same or very similar Samsung cells. These cells are 3.7V lithium ion batteries rated at 2900 mAh. You may find someone willing to repair it for you if you're not comfortable doing it yourself.
That's a large battery pack at 48V 20Ah. 13S/7P = 91 3.7V cells. At ~ $5/cell (retail) that's $455 just for the cells alone. You should be able to rebuild the battery with the good cells. You just won't have the same capacity. Make sure you check the Battery Management hardware module to make sure it's still functioning properly.
The BMS will switch your battery off when the voltage gets too low, not the controller. The bms decides what the fully charged and discharged voltages are.
You’d have to run it until it quits.
True the BMS will shut the battery down at some pre-determined low voltage. You can have the controller shut your motor assist off at a voltage of your choosing as well. This will allow you to shut your battery usage off before the BMS turns off your battery.
Just a quick update. I have a little over 600 miles on this bike conversion. After about 400 miles I decided to add a disc brake to the rear wheel. The bike originally had V brakes. The rear brake never gave very much stopping power and with the added weight of the motor and battery it was even more useless. Since the bike frame does not have mounts for disc break calipers I had to design and machine a bracket to fit using the mounting holes available on the rear dropouts. Of course I also had to buy a new rear wheel as the original one did not have a hub for a disc rotor. The results are amazing. Much more stopping power from the rear. Well worth the effort and minimal cost.
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Nyack Rider
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sweet conversion. nice job!
"A"
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Majority of stopping power is in the front wheel, with smaller wheel diameter, rim brake in the front would heat up the tube/tire much quicker than the rear brake.
I would imagine the disc brake should go to the front wheel first.
I would imagine the disc brake should go to the front wheel first.
