Bafang 750w too powerful?

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wesblog   1 mW

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Bafang 750w too powerful?

Post by wesblog » Aug 31 2017 11:48pm

I am used to riding a TSDZ2 500w bike with a 10AH 48v battery.

I recently built a BBS02b 750w bike with a 14ah 48v battery.

My problem is that the Bafang seems to provide power in large short segments. While the TSDZ2 was more of a smooth ride with power equally provided as I pedaled, the Bafang will jerk me forward with 800w of power then quickly slow down. When I am riding on flat ground it delivers 800w for a few seconds then delivers <50w for a few seconds. As my speed begins to slow, back up to 800w.

Even at assist level 1 I can't get the bike to deliver a smooth level of power. Is there an eco mode or some way to make the BBS02b ramp up and down more slowly?

craneplaneguy   10 kW

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Re: Bafang 750w too powerful?

Post by craneplaneguy » Sep 01 2017 9:06am

You need a programming cable and the knowledge to use it, which I don't have but I know others here do. You should be able to get in there and fine tune things, it's a common issue. One simple thing I did was when I found out my display could be set to have 10 levels of PAS instead of 5, I went to 10 levels, now my #1 setting is not too powerful, and I didn't have to mess with the programming thing. More then anything though, I just use throttle, while pedaling, it's an infinitely variable pedal assist and once you learn how to "feather" it in, it makes, for me anyway, PAS passe.

docw009   100 kW

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Re: Bafang 750w too powerful?

Post by docw009 » Sep 01 2017 9:47am

I also went to 9 PAS levels from the default on my BBS02. Gives more granularity in pedal assist. I can mope along at 12 mph in PAS 1. At that speed, I prefer PAS 0 and occasional throttle blips, but I'm not sure all BBS02's will run throttle at PAS 0.

I doubt you can ever pedal with power assist under 10 mph unless you reprogram the actual motor assist for each power level, like craneplane says. I did not want to get into reprogramming so I don't have the cable/software.

tommie   10 W

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Re: Bafang 750w too powerful?

Post by tommie » Sep 01 2017 11:36am

wesblog wrote:I am used to riding a TSDZ2 500w bike with a 10AH 48v battery.

I recently built a BBS02b 750w bike with a 14ah 48v battery.

My problem is that the Bafang seems to provide power in large short segments. While the TSDZ2 was more of a smooth ride with power equally provided as I pedaled, the Bafang will jerk me forward with 800w of power then quickly slow down. When I am riding on flat ground it delivers 800w for a few seconds then delivers <50w for a few seconds. As my speed begins to slow, back up to 800w.

Even at assist level 1 I can't get the bike to deliver a smooth level of power. Is there an eco mode or some way to make the BBS02b ramp up and down more slowly?
Ok, easily solved!
First get yourself the programming cable, readily available from most ebike dealers and Ebay, Amazon etc.
Now go here https://penoff.wordpress.com/2016/01/13 ... #more-1538 and download the programme for the Laptop. You will find various .el files with which to program into the controller, try them and you`ll find one which suits you.

neil.b   1 mW

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Re: Bafang 750w too powerful?

Post by neil.b » Sep 01 2017 11:48am

Make sure you backup your original settings as well, just in case you need to return it to standard for any reason. ;)

wesblog   1 mW

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Re: Bafang 750w too powerful?

Post by wesblog » Sep 01 2017 5:44pm

Thanks for all the great replies guys!

I like to tinker with things so I may order a cable. But I'll try the 10 levels of assist too.

2old   100 kW

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Re: Bafang 750w too powerful?

Post by 2old » Sep 01 2017 7:44pm

I don't want to "learn" programming either and with nine levels of assist, my system seems to operate perfectly. Seldom am above level three and very infrequently employ the throttle for a severe (to me) part of an ascent. Also using the Luna 30 tooth ring with 11-17-28 cassette in 8-speed spacing.

d8veh   100 GW

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Re: Bafang 750w too powerful?

Post by d8veh » Sep 02 2017 4:57am

2old wrote:I don't want to "learn" programming either and with nine levels of assist, my system seems to operate perfectly. Seldom am above level three and very infrequently employ the throttle for a severe (to me) part of an ascent. Also using the Luna 30 tooth ring with 11-17-28 cassette in 8-speed spacing.
You don't have to learn anything. Programming the controller is a simple procedure. It's no more difficult than cleaning your bike or fixing a puncture.

2old   100 kW

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Re: Bafang 750w too powerful?

Post by 2old » Sep 02 2017 12:48pm

d8, thanks; my system is operating very well for me now; it's nice to know that it can be modified if needed.

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fechter   100 GW

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Re: Bafang 750w too powerful?

Post by fechter » Sep 02 2017 4:08pm

There seems to be a bug present in some BBSHD controllers that causes some serious surges in power when the PAS engages. I had it in mine, and have heard of others with the same problem. I solved my problem by disabling the PAS permanently and I only use the throttle. Others have solved the problem by replacing the controller.

On mine, if I pedaled when using the throttle, it would do a launch and practically throw me off. PAS was sort of full blast or nothing. I tried changing all sorts of settings and used profiles known to be good from others but nothing solved the problem.

Not sure if this is what yours is doing, but it sounds similar. Try tweaking the settings first.
"One test is worth a thousand opinions"

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Rassy   10 MW

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Re: Bafang 750w too powerful?

Post by Rassy » Sep 03 2017 11:45am

I had a 48V 500W BBS02 on each of my trikes and recently switched both of them over to 48V 750W BBS02. I believe the controllers are all the same except for the max amp settings.

Both of the 500W Bafangs operated about the same. PAS was smooth but constantly altered the power up and down which made the speed vary by a few miles per hour. This was noticeable, but not too bad. Both would "Launch with a jerk" when using the throttle unless I first fully engaged the drive train using PAS. Once everything was running under throttle, with or without pedaling, adjusting the speed to suit was smooth.

With both of the 750W Bafangs the PAS system ramps up a little slower and when cruising along at a constant speed there is very little pulsing, in fact you wouldn't even notice it if you didn't see the speedometer speed changing a little. However, on one of them the throttle is very smooth and easy to feather up and down as desired, and on the other one the throttle doesn't kick in until almost the half way point and then is very difficult to feather, constantly jerking on the chain as the power surges on and off, but works fine at the top end. I don't use the throttle much anyway, but plan to switch the two throttles to see if the issue is with the throttle or the controller. These are the same throttles that were on the trikes with the 500W Bafangs, but I might not have noticed the issue with the lower power unit, plus I only used the throttles to accelerate quickly across an intersection or make a faster run to get off a shared road quickly.

I don't have a programming cable and not too keen to start making controller changes. I have heard that some values are critical and you can destroy the controller if setting them wrong.
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

d8veh   100 GW

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Re: Bafang 750w too powerful?

Post by d8veh » Sep 05 2017 6:09am

Every BBSxx seems to be programmed differently. Many of them have diabolical settings - in particular, the keep current. You should get a programming cable to see what you have.

hemo   100 W

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Re: Bafang 750w too powerful?

Post by hemo » Sep 05 2017 7:32am

My 350w bbs01 was a bit strange the 'Keep current' was a meagre 20% and the start current was at 100%.

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Rassy   10 MW

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Re: Bafang 750w too powerful?

Post by Rassy » Sep 05 2017 9:49am

d8veh said:
Every BBSxx seems to be programmed differently. Many of them have diabolical settings - in particular, the keep current. You should get a programming cable to see what you have.
Good advice and a good reason to get the programming cable and software even if I never make any changes to the initial default settings. Thanks
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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Rassy   10 MW

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Re: Bafang 750w too powerful?

Post by Rassy » Sep 17 2017 7:41pm

Bit the bullet and downloaded the Penoff software and purchased the interface cable from Luna. There were only two differences. On the smoother operating system the Slow Start Mode was set at 4 and the Current Decay was set at 8. On the other system the Slow Start Mode was set at 3 and the Current Decay was set at 4. I currently have no idea what these settings are for, but I changed the "jerky" system to match the smoother one and there was an improvement. However it's raining here now, so the ride was pretty short.

Also set the Max Amps down to 18 on the tadpole since it just has a 10AH Ping battery.
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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Rassy   10 MW

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Re: Bafang 750w too powerful?

Post by Rassy » Sep 17 2017 7:55pm

Here are all the controller settings from my system that cannot be changed directly from the display buttons:

Bafang Controller Configurations: (Hardware V1.1, Software V2.0.1.1, 48V, 25A Max)

BASIC:...................Tadpole Trike................Delta Trike
Low battery Protection.....41...........................41
Current Limit..................25...........................25
Assist Current Limit %s:
0.....................................1............................1
1...................................10...........................10
2...................................20...........................20
3...................................30...........................30
4...................................40...........................40
5...................................50...........................50
6...................................70...........................70
7...................................80...........................80
8...................................90...........................90
9..................................100.........................100
Assist Speed Limit %s:
0......................................1............................1
1...................................100........................100
2...................................100........................100
3...................................100........................100
4...................................100........................100
5...................................100........................100
6...................................100........................100
7...................................100........................100
8...................................100........................100
9...................................100........................100

PEDAL ASSIST:
Designated Assist Level--------By Display Command-------
Start Current %.................10.........................10
Slow Start Mode..................3...........................4
Start Degree.......................4...........................4
Work Mode................Undetermined.........Undetermined
Stop Delay........................25..........................25
Current Decay.....................4............................8
Stop Decay.........................0............................0
Keep Current.....................60..........................60

THROTTLE HANDLE:
Start Voltage......................11.........................11
End Voltage........................35.........................35
Mode.............................Current...................Current
Designated Assist Level..........9...........................9
Start Current %...................10.........................10

EDIT: Since my delta trike runs smooth as is, I made the following changes to my tadpole trike, which also resulted in smooth operation, mainly when transitioning from PAS to throttle usage. No long rides yet due to weather.

Made the two changes where differences were noted: Slow start mode = 4 and current decay = 8.
Changed current limit to 18A because the tadpole only carries a 10AH LiFeP04 battery. In conjunction with this change I added 5% to each of the assist current limits 1 through 5, mainly so in assist level 1 the motor wouldn't be starved for amps. (18A x 15% - 2.7A).

After some more rides I may or may not try some more fine tuning. Many thanks to all that encouraged me to get the programming cable and download the Penoff software. It was easy to download and use, and well worth it.
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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Rassy   10 MW

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Re: Bafang 750w too powerful?

Post by Rassy » Sep 22 2017 6:20pm

I think I now understand why one of my new 48V 750W Bafang BBS02s is smooth when going from pedaling in any PAS level, including 0, to applying throttle and the other one is jerky. The jerky one apparently has a dedicated Gear Sensor (There is an extra unused wire coming from the controller).

In reading comments at the end of "A Hacker's Guide to Programming BBS02 & BBSHD" on "Electric Bike Blog.com":

https://electricbike-blog.com/2015/06/2 ... the-bbs02/

I found this statement:
Abd Alrahman Swidah June 3, 2017 at 1:04 am
Hi Thomas,
I guess your motor has a dedicated gear sensor. I have a BBS02 which was manufactured last year july, it was perfect until I decided to give it to my friend and buy my self a new BBS02 with dedicated gear sensor. The problem is not solvable, Bafang’s new programming made the pas override the throttle, except when the throttle is 100% which is not smooth at all and may destroy the internal parts. It just feels wrong, I want to pedal with the motor in pas 0 in a smooth way. I just replaced the controller to my old one, and it solved my problem :D.
So here are my symptons:

When pedaling along at any cadence in any gear in any PAS level the throttle will not engage until at least half throttle, at which time it comes on strong and jerky. If not pedaling, or I stop pedaling, the throttle works normal and smooth as it should. Is there any solution to this problem, short of installing a new controller without the gear sensor?
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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fechter   100 GW

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Re: Bafang 750w too powerful?

Post by fechter » Sep 22 2017 9:29pm

That sounds exactly like the problem I had. Nice to know why it's happening at least. I don't know of any way to correct it other than replacing the controller. I gave up and disabled the PAS.
"One test is worth a thousand opinions"

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Rassy   10 MW

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Re: Bafang 750w too powerful?

Post by Rassy » Sep 25 2017 8:04pm

fechter wrote:
That sounds exactly like the problem I had. Nice to know why it's happening at least. I don't know of any way to correct it other than replacing the controller. I gave up and disabled the PAS.
I just received a reply from Luna and they confirmed that using the throttle while pedaling no longer works on the new models because of programming changes Bafang made to support the gear sensor feature. The replacement controller Luna currently advertises has the gear sensor feature so I have asked if they have a replacement controller that fits the new units and does not have the gear sensor feature.

Anyway, I really enjoy just using the PAS system most of the time and normally just use the throttle to quickly cross a wide street or get off a shared stretch of road. The transition from pedaling along using PAS to getting quick acceleration using the throttle is very smooth if I stop pedaling at the exact same
time that I hit the throttle. If trying to accelerate quickly from a stop I like to apply hard pedal assist along with the throttle, at least until I can't keep up with the cadence, and I'll just have to refine my technique and remember which trike I am riding.

In looking at other blogs, etc. this change caught a lot of us unawares. I don't know how to spread the word, but it seems the vendors should make sure their customers are aware of the change and what they are buying.

EDIT: I purchased and installed a new controller, manufactured 09/14/17, that does not have the Dedicated Gear Sensor/Cable, and it also has the problem with not being able to pedal with normal throttle usage. So the conclusion I have to make is that Bafang made some other change to the controllers that doesn't have anything to do with the Gear Sensor.

Edit: There is another thread discussing this problem here:

https://endless-sphere.com/forums/viewt ... 28&t=91306
-Rassy-
One Tadpole Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 28&t=69419
One Delta Trike equipped with a Bafang BBS02
https://endless-sphere.com/forums/viewt ... 0#p1291260

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