Tom L
1 kW
I'm tempted to do something similar. I'm sick of the motor outpacing me with the speed set to 100%. I like an 80rpm cadence so will set the speed to 67% for PAS 2 to 8 and see how my commute goes tomorrow.
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Programming the Bafang Middrive BBS01+BBS02
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0utrider
100 W
I'm eager to hear your results!Tom L said:
darth_elevator
100 W
Good to hear!0utrider said:
Ken Taylor
100 W
There is still some interest in how to avoid damaging the controller.
With controller settings to produce constant power regardless of cadence you should see constant input power/current supplied to the motor until the phase current limiting takes effect after which input power/current should drop. This matters because electrical power supplied to a motor is turned into torque and rotational speed, measured as cadence with the BBS0x. Multiplying cadence and torque gives power out. Any difference between input and output power appears as heat inside the motor and controller. Torque increases up to a maximum and then remains constant, so as a motor slows at constant torque its power output drops in proportion to the cadence and the extra power becomes waste heat. Too much waste heat and something will get hot enough to fail. In the BBS02 it seems to be the controller FETs that fail first and all the reports I've read here are of BBS02 failures, probably because it has a higher input power, so generates waste heat faster. To test for phase current limiting, measure the input current/power, slow the motor and look for a drop. The danger in this test is in deliberately putting the motor into a situation where it will fail if there isn't phase current limiting or it stays in that state for long enough to get too hot. I tried a low power input of 83 watts, then using the brakes reduced speed gradually and plotted the data with Strava.
The 17 rpm cadence at the cross hair is far lower than anyone would ride at. It is also the lowest the cadence sensor, a Garmin GSC 10 could measure with the magnet passing the sensor every 4 seconds or so. The cadence measurement after this is erroneous but lower than 17 rpm. How much lower can be estimated from the speed trace which is better at lower speeds because the wheel rotation is faster and the magnet passes the sensor more often. The ratio of minimum speed to speed at 17 rpm suggests a minimum pedal cadence of 10 rpm. Cadence measurement is imprecise at such low speeds but to an observer it seems like the motor is barely turning. The motor ran at low cadences for about 16 seconds and there was no reduction in input power. There was a slight increase from 83 watts to 86 watts but that would be due to the imperfect constant current control. This suggested no phase current limiting. I also tried a higher power.
Again there is no sign of phase current limiting.
This testing supports the view that "you need to try and keep the cadence up to a reasonable level most of the time" and it would be better again if this could be enforced by the controller.
I previously suggested a model for the effect of Time of stop(x10ms) which I've invalidated by testing. I haven't got another yet but reducing this value did raise the minimum cadence. Setting a low enough value should ensure the motor only operates at a safe cadence under PAS.
One person lost two of them.jpo said:
Em3EV has suffered warranty claims and astmacca sums up the current, incomplete, consensushie2kolob said:
Keeping the cadence up wouldn't be necessary if there was phase current limiting in the Bafang controller which Em3EV said it didn't have and Kepler thought it probably did. I tried to resolve this uncertainty in the last series of tests.astmacca said:
With controller settings to produce constant power regardless of cadence you should see constant input power/current supplied to the motor until the phase current limiting takes effect after which input power/current should drop. This matters because electrical power supplied to a motor is turned into torque and rotational speed, measured as cadence with the BBS0x. Multiplying cadence and torque gives power out. Any difference between input and output power appears as heat inside the motor and controller. Torque increases up to a maximum and then remains constant, so as a motor slows at constant torque its power output drops in proportion to the cadence and the extra power becomes waste heat. Too much waste heat and something will get hot enough to fail. In the BBS02 it seems to be the controller FETs that fail first and all the reports I've read here are of BBS02 failures, probably because it has a higher input power, so generates waste heat faster. To test for phase current limiting, measure the input current/power, slow the motor and look for a drop. The danger in this test is in deliberately putting the motor into a situation where it will fail if there isn't phase current limiting or it stays in that state for long enough to get too hot. I tried a low power input of 83 watts, then using the brakes reduced speed gradually and plotted the data with Strava.
The 17 rpm cadence at the cross hair is far lower than anyone would ride at. It is also the lowest the cadence sensor, a Garmin GSC 10 could measure with the magnet passing the sensor every 4 seconds or so. The cadence measurement after this is erroneous but lower than 17 rpm. How much lower can be estimated from the speed trace which is better at lower speeds because the wheel rotation is faster and the magnet passes the sensor more often. The ratio of minimum speed to speed at 17 rpm suggests a minimum pedal cadence of 10 rpm. Cadence measurement is imprecise at such low speeds but to an observer it seems like the motor is barely turning. The motor ran at low cadences for about 16 seconds and there was no reduction in input power. There was a slight increase from 83 watts to 86 watts but that would be due to the imperfect constant current control. This suggested no phase current limiting. I also tried a higher power.
Again there is no sign of phase current limiting.
This testing supports the view that "you need to try and keep the cadence up to a reasonable level most of the time" and it would be better again if this could be enforced by the controller.
I previously suggested a model for the effect of Time of stop(x10ms) which I've invalidated by testing. I haven't got another yet but reducing this value did raise the minimum cadence. Setting a low enough value should ensure the motor only operates at a safe cadence under PAS.
Ken Taylor
100 W
On a slightly different note I'm finding habituation kills your judgement on the effect of assist. The first taste seems great but like a heroin addict, you keep needing more to get the buzz and withdrawal is horrible.
I ride around Lake Burly Griffin several times a week which is probably Australia's most scenic inner city cycling route. Usually I have the assist off on this route and it's mostly pleasant. Over the weekend, Lifecycle was held there which involves riding around the lake as many times as you can in 30 hours. The two best riders did 666 km and 645 km. I rode with the 645 km guy about 3 hours before the end and he was looking a bit haggard but it is a staggering distance, achieved, like the famous Cliff Young Sydney to Melbourne race by almost never stopping. He said he'd done 24 hours a few times without trouble but he was finding 30 hours tough. He was trying to make it look easy, still trying to race, but I got the impression, by 27 hours, he could barely tell which way was up. Never being far from a charger, I was liberal with the assist and still managed less than half the distance of the best unpowered guy.
Yesterday I did the route, as usual, without assist and it seemed much harder than it did last week. The modest climbs were depressingly steep and even the flats sloped upwards. The ride had become a hard grind so just a couple of days is enough to change your perception of assist, even on a route you are very familiar with. This would also change your opinion of desirable assist settings so, when setting up your controller a factor to be considered is your level of addiction.
I ride around Lake Burly Griffin several times a week which is probably Australia's most scenic inner city cycling route. Usually I have the assist off on this route and it's mostly pleasant. Over the weekend, Lifecycle was held there which involves riding around the lake as many times as you can in 30 hours. The two best riders did 666 km and 645 km. I rode with the 645 km guy about 3 hours before the end and he was looking a bit haggard but it is a staggering distance, achieved, like the famous Cliff Young Sydney to Melbourne race by almost never stopping. He said he'd done 24 hours a few times without trouble but he was finding 30 hours tough. He was trying to make it look easy, still trying to race, but I got the impression, by 27 hours, he could barely tell which way was up. Never being far from a charger, I was liberal with the assist and still managed less than half the distance of the best unpowered guy.
Yesterday I did the route, as usual, without assist and it seemed much harder than it did last week. The modest climbs were depressingly steep and even the flats sloped upwards. The ride had become a hard grind so just a couple of days is enough to change your perception of assist, even on a route you are very familiar with. This would also change your opinion of desirable assist settings so, when setting up your controller a factor to be considered is your level of addiction.
astmacca
100 W
I'd agree with you 100% on that one Ken. I keep wanting to go back and play with the Speed% settings and have to keep telling myself "nooooooooooo.....just go with these for a while and pedal you lazy git!!" Even on the settings i run there is a temptation to jack it up from 20% - 30% assist "just for a little while" on my normal commute i sometimes hear myself think.
Really, i have to get back on the other, pedal only bike every now and again to remember how nice the electric is to ride.
And thanks for the interesting quantitative stuff you have been posting.
bgt
100 W
I keep reading that everybody with a Bafang midmotor could kill its controller quite easy by using too much power=low cadence. Is this mostly true with the 48V models? Especially the 750W? I have 2off BBS-01/250W systems as we have no hills in this country(I live near the sea)..........only in the south but they are tiny compared to where most of you live, like Ken.
I use the throttle a lot, especially from standstill and like the acceleration. My motor is never hot even after a 40km ride through the dunes which are a bit hilly :lol: In the worst case my motor feels like 30C(20C outside temp.).
I use the throttle a lot, especially from standstill and like the acceleration. My motor is never hot even after a 40km ride through the dunes which are a bit hilly :lol: In the worst case my motor feels like 30C(20C outside temp.).
Kepler
10 MW
No doubt assist is addictive and it is very easy to get lazy. I employ two methods to keep me honest with the level of assist. First thing is battery size. I keep my battery capacity down to around 200 Whrs. I then adjust my riding style to suit the distance I need to travel. My typical commute is 25km to 30km and can average 30kph with this amount of battery. The small battery has the other advantage of reduced overall bike weight so pedaling with assist off or at the lowest setting becomes less of chore.
Second strategy is to ride using a heart rate monitor. Know your body and understand how hard you are working. Using the heart rate method, assist level becomes less of an issue. As long as your heart rate is within the target zone, you are are getting the exercise you need. My average heart rate is typically higher on my BBS equipped then it is on my high end carbon road bike while riding hills.
I love riding my road bike and enjoy the efficiency that comes with a lightweight and stiff platform however for commuting duties, the full suspension BBS equipped bike make far more sense both in terms of safety and comfort.
Below is a sample of my my normal work commute on the BBS equipped bike. I get to the office quicker on this bike then if I battle the traffic in my car.
Second strategy is to ride using a heart rate monitor. Know your body and understand how hard you are working. Using the heart rate method, assist level becomes less of an issue. As long as your heart rate is within the target zone, you are are getting the exercise you need. My average heart rate is typically higher on my BBS equipped then it is on my high end carbon road bike while riding hills.
I love riding my road bike and enjoy the efficiency that comes with a lightweight and stiff platform however for commuting duties, the full suspension BBS equipped bike make far more sense both in terms of safety and comfort.
Below is a sample of my my normal work commute on the BBS equipped bike. I get to the office quicker on this bike then if I battle the traffic in my car.
Attachments
tomjasz
1 GW
BBS01 350W 7 miles, WOT, zero cadence, warm never hot. On flat ground. Actually not much warmer than level 2 pedal assist at 14MPH. I'm committed to doing a better job of temp sensing but I think as and old guy grocery bike it'll never over heat. Realizing that most adapting want speed and power. For my fellow dorks this is likely one reliable rig.
If anybody is still interested in a pre-made Bafang BBS-01/02 programming USB cable, BTN on AliExpress is selling one for $50.00 plus $17.85 shipping.
http://www.aliexpress.com/store/product/8fun-bafang-center-motor-middle-drive-motor-kit-reprogram-cable/904105_1998539445.html
Kind of expensive considering you can make your own programming cable, which is what the BTN cable looks like. A USB-to-TTL cable can be ordered on Amazon for around $5 including free shipping in the US. Female-to-female jumpers cost another $5. You could connect the USB cable with the 3 female connectors, along with one additional female-to-female connector, directly to the male connector from the controller. Please be careful of your connections or you will fry your controller.
Otherwise you could make a really nice programming cable like pexio did back on July 2nd, Page 12 on this tread. You can order a Bafang BBS02 Controller Display Extension Cable (1m) from em3ev.com for $8.00 plus some amount for shipping. Just follow pexio's instructions.
On a positive note, my new Bafang 36v 500w mid-drive that I bought during the Alibaba 11/11 Sale yesterday has already shipped from BTN to Alibaba's warehouse. So I'm assuming it will be shipping to the US shortly. Can't wait to install it on my new road bike.
http://www.aliexpress.com/store/product/8fun-bafang-center-motor-middle-drive-motor-kit-reprogram-cable/904105_1998539445.html
Kind of expensive considering you can make your own programming cable, which is what the BTN cable looks like. A USB-to-TTL cable can be ordered on Amazon for around $5 including free shipping in the US. Female-to-female jumpers cost another $5. You could connect the USB cable with the 3 female connectors, along with one additional female-to-female connector, directly to the male connector from the controller. Please be careful of your connections or you will fry your controller.
Otherwise you could make a really nice programming cable like pexio did back on July 2nd, Page 12 on this tread. You can order a Bafang BBS02 Controller Display Extension Cable (1m) from em3ev.com for $8.00 plus some amount for shipping. Just follow pexio's instructions.
On a positive note, my new Bafang 36v 500w mid-drive that I bought during the Alibaba 11/11 Sale yesterday has already shipped from BTN to Alibaba's warehouse. So I'm assuming it will be shipping to the US shortly. Can't wait to install it on my new road bike.
jpo
100 mW
One does build a tolerance to speed and power. Slowing down a touch can put things in check and running out of juice anything short of the last climb can be a serious buzz kill.
As for the motor out pacing I feel this can be reasonable managed by changing assist levels even if the speed is set to 100%. It would be nice if the assist button was easier to change. I find I need to look for the button and at the screen doesn't sound like much but if navigating a busy intersection or technical trail I like to keep focused.
One thing I would like to improve on is the walking assist mode. I find the walking mode is generally too slow and pushing and holding the (-) button is not great. If the bike hits a bump in walking mode it's hard to keep the button depressed, and controlling the throttle is less that idea as well.
I was thinking I could set the speed limit really low in assist level 1 and use it as a walking mode. I have not tried this yet.
Any thoughts?
thanks
As for the motor out pacing I feel this can be reasonable managed by changing assist levels even if the speed is set to 100%. It would be nice if the assist button was easier to change. I find I need to look for the button and at the screen doesn't sound like much but if navigating a busy intersection or technical trail I like to keep focused.
One thing I would like to improve on is the walking assist mode. I find the walking mode is generally too slow and pushing and holding the (-) button is not great. If the bike hits a bump in walking mode it's hard to keep the button depressed, and controlling the throttle is less that idea as well.
I was thinking I could set the speed limit really low in assist level 1 and use it as a walking mode. I have not tried this yet.
Any thoughts?
thanks
darth_elevator
100 W
The extension cables I ordered from Tony arrived over the weekend. I wired one of them up and it's working great. So much nicer and quicker than my jumper method.tln said:
Not sure how many more Tony has, but if anyone is still looking for a display extension cable to use as a programming cable, drop him a line. I can now personally vouch for his speedy shipping and great price, as well as the fact that these are indeed the correct cables.
tln
100 W
darth_elevator said:The extension cables I ordered from Tony arrived over the weekend. I wired one of them up and it's working great. So much nicer and quicker than my jumper method.tln said:
Not sure how many more Tony has, but if anyone is still looking for a display extension cable to use as a programming cable, drop him a line. I can now personally vouch for his speedy shipping and great price, as well as the fact that these are indeed the correct cables.
I'm out of cables now. They went quick
0utrider
100 W
tln said:I'm out of cables now. They went quick
Phew! I'm one of the lucky ones!
0utrider
100 W
True!darth_elevator said:I can now personally vouch for his speedy shipping and great price, as well as the fact that these are indeed the correct cables.
skyungjae
10 kW
Well, I certainly hope I don't burn out my motor.
I'm running no throttle & only 2 PAS modes (slow & go). :?
I'm running no throttle & only 2 PAS modes (slow & go). :?
k90211lee
1 mW
tln said:I'm out of cables now. They went quick
Just saw this, If you decide to make more cables, I love get one.
K.
Somebodystopme!!
10 W
- Joined
- Dec 24, 2013
- Messages
- 72
Has anyone experienced a slow throttle response when pas is set to zero?
I just programmed my new BBS02 for this and it takes a good 2-3 seconds for the half twist throttle to get to full power. It ramps up in distinct stages. Maybe 5 or so.
I changed on my throttle handle tab, designated assist to 9, and speed limited to by display command. On the basic tab I have assit0 limit current to zero and limit speed to 100%
Does this sound familiar to anyone?
I just programmed my new BBS02 for this and it takes a good 2-3 seconds for the half twist throttle to get to full power. It ramps up in distinct stages. Maybe 5 or so.
I changed on my throttle handle tab, designated assist to 9, and speed limited to by display command. On the basic tab I have assit0 limit current to zero and limit speed to 100%
Does this sound familiar to anyone?
Here is a link from the French E-bike forum. If you open it in the Google Chrome browser it will automatically detect the language and ask if you want it translated. This link has the info on how the French are programming the BBS01/BBS02. Perhaps it may be of help.
http://cyclurba.fr/velo/765/Bafang-...rogrammation-reprogramation-programation.html
http://cyclurba.fr/velo/765/Bafang-...rogrammation-reprogramation-programation.html
Somebodystopme!!
10 W
- Joined
- Dec 24, 2013
- Messages
- 72
Here is a good source of info from Australia too.
http://www.emax-ebikes.com.au/faq.html
http://www.emax-ebikes.com.au/uploads/3/7/4/4/37442009/programming_bafang_bbs.pdf
http://www.emax-ebikes.com.au/faq.html
http://www.emax-ebikes.com.au/uploads/3/7/4/4/37442009/programming_bafang_bbs.pdf
pjgold
100 W
Somebodystopme!! said:
I have always had this issue, but I just spotted on the French forum that setting "speed limited by display command" is the culprit. I reset mine to 40kph and hey presto no more lag interesting my doesn't limit to 40kph either, no load in top gear is 58 kph.
I'll have to try the PAS now and see if they is any difference with that.
Somebodystopme!!
10 W
- Joined
- Dec 24, 2013
- Messages
- 72
Same here. Just changed it yesterday and now all is right with the world....pjgold said:
0utrider
100 W
After getting another ride in, I'm thinking I'm ok with standard programming and may only add throttle to setting 0.
I had a great time in PAS settings 1 & 2 out of 9. Fingers crossed I don't mess up anything when hooking up the progamming cables.
I had a great time in PAS settings 1 & 2 out of 9. Fingers crossed I don't mess up anything when hooking up the progamming cables.
I've been doing my best to use the information in this thread to eliminate the cogging during PAS on my 36V, 500W BBS-02. It's really jerky at low RPM!
I made a programming cable out of a genuine display extension cable and one of grin tech's usb -> ttl cables. For those who don't know, the ttl cable's green wire is RX, red is TX, and black is ground. I'm attaching a picture of the cable I made - I'm pretty sure I did it right!
I plugged this cable into the controller-side of the unit, then into my windows 7 computer, turned on the battery, and can't get the software to recognize this unit. In my "Devices and Printers", under "Unspecified", I get a FT230X Basic UART that under status says "Needs Troubleshooting" whenever the USB cable is plugged in - regardless of what the other side is connected to. Additionally, the red LED on the speedo sensor doesn't light up when I turn the battery on. However, this light doesn't initially turn on when I power up the system normally. It only lights up when the wheel starts spinning.
Any ideas on why I'm not able to connect this unit to the controller software?
1407256884 is the serial # of my unit, if that's any help.
Thanks in advance for the help - I'm blown away by the support I've received on this forum already.
I made a programming cable out of a genuine display extension cable and one of grin tech's usb -> ttl cables. For those who don't know, the ttl cable's green wire is RX, red is TX, and black is ground. I'm attaching a picture of the cable I made - I'm pretty sure I did it right!
I plugged this cable into the controller-side of the unit, then into my windows 7 computer, turned on the battery, and can't get the software to recognize this unit. In my "Devices and Printers", under "Unspecified", I get a FT230X Basic UART that under status says "Needs Troubleshooting" whenever the USB cable is plugged in - regardless of what the other side is connected to. Additionally, the red LED on the speedo sensor doesn't light up when I turn the battery on. However, this light doesn't initially turn on when I power up the system normally. It only lights up when the wheel starts spinning.
Any ideas on why I'm not able to connect this unit to the controller software?
1407256884 is the serial # of my unit, if that's any help.
Thanks in advance for the help - I'm blown away by the support I've received on this forum already.
Attachments
Tom L
1 kW
Try installing the windows driver on this page then plug the device in. If that does not work it may be a counterfeit USB device.liontail said:
http://www.ftdichip.com/Drivers/VCP.htm
That's odd. It should light up when you first turn the display on. It will go out when the magnet passes it for the first time then pulse on for each subsequent pass.liontail said:
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