BBS01B 36V 250W - trying with higher voltage [success]

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

BBS01B 36V 250W - trying with higher voltage [success]

Post by Wizzeros » Apr 30 2018 7:34am

Hello everyone,

I tried in a different forum, but did not receive any help, so I would like to ask you.

Is it possible to make my motor BBS01B 36V 250W to work on 52V with standard controller (if not 52V, then 48V?)? I know about "error 07 - overvoltage protection", but everything else looks identical inside the controller like in 48V version (let's say BBS02 types). Also, If 48V version works perfectly fine with 52V battery, what is the highest voltage level for 36V version?

I tried to find anything about HVC deactivation, but without succcess. Does enyone know something more about how to do it? I mean if there is a way of doing it in the hardware, like resolder parts inside controller, it would be also great.

If you have any information about this and can help - many thanks!

It is really, really hard to find anything close to this matter instead of "buy different controller", or "put 36V battery back" info. As long as the insides seems to be the same like in other controllers (but it is also hard to find any info about it so I can be wrong), then the HVC is one of the only things preventing it to work.

Thank you for all the help!
Last edited by Wizzeros on Jul 02 2018 8:36am, edited 1 time in total.

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » Apr 30 2018 9:02am

The parts on the controller are rated for 63v, so you can go with a 52v (14s Liion) maximum.
The Low Battery Protection voltage can be configured in the software using a laptop and programming cable.

Yes, there is a way to change it with hardware but a little challenging. You would need to build a "voltage dropper" circuit and place it in series with the B+ line going to the display. The display will then "see" a lower voltage than what's going to the FETs.
"One test is worth a thousand opinions"

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » Apr 30 2018 9:37am

Thank you fechter!

That's exactly what I was thinking, but apparently sometimes people have "error 07 - overvoltage protection" but I found only examples where it appeared along with 36V batteries for some unknown reason, like it was a problem with something else than battery itself.

I could not find any review where someone intentionally tried to connect 52V battery do bbs01 36V 250W.

The programming cable is on the way to me. I have also separate BMS in my battery pack, so I could just rely on it and turn off LVC in motor controller/display.

Do you think error 07 won't appear without hardware tweaking?

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » Apr 30 2018 9:46am

Wizzeros wrote:
Apr 30 2018 9:37am

Do you think error 07 won't appear without hardware tweaking?
I have never tried it on a BBS02, only a BBSHD but they are essentially the same other than the FET count. You don't get the error until it reaches 63v.

Try it and see what happens. There could be differences in the firmware.
"One test is worth a thousand opinions"

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 01 2018 2:34am

Thank you fechter,

I will try to connect the 52V battery as you adviced. If it works, then the heat generated in controller and motor winding shall be lower than in the 36V version (regarding riding with the same power consumption), because of the lower amperage. That's why I do not worry about the durability of such a setting. I am aware about a higher cadence, but I don't mind unless it works properly.

However, is it possible to add another set of transistors in parallel to the existing ones? It would divide the heat from the current ones and make the controller more robust. For now, it is just a thought, but it is worth considering in the future.

I will let you know if it works with 52V!

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » May 01 2018 8:02am

Wizzeros wrote:
May 01 2018 2:34am
However, is it possible to add another set of transistors in parallel to the existing ones? It would divide the heat from the current ones and make the controller more robust. For now, it is just a thought, but it is worth considering in the future.

I will let you know if it works with 52V!

Probably not, as there isn't enough room, but it is possible to replace them with better ones. Stock are mostly 75NF75 but at some point they started using IRFB3077s, which are significantly better in terms of heat production. If your controller isn't potted, you could see which ones are installed. There are even better parts out there. Keep in mind that replacing the FETs is pretty difficult and it's easy to damage the board when removing the old ones but several people have done it.
"One test is worth a thousand opinions"

User avatar
eCue   10 kW

10 kW
Posts: 632
Joined: Nov 03 2017 5:14pm
Location: Vancouver Island , Canada

Re: BBS01B 36V 250W - trying with higher voltage

Post by eCue » May 01 2018 4:23pm

My KT controller ( 22A kt z variety ) works with both 36 & 48v+ batteries via a setting plus it has custom adjustable voltage cut off points set via the lcd5 display. Its likely the bafang display does this as well.

The little 350w 36v mxus xfo7 reaches around 40 kph with a 14.8 amp limit on the 48v pack. A 52v pack would be a better/ faster choice :)
Solar charge station on wheels join the Revolution

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 17 2018 2:40am

Thank you for all your help. Yesterday, I finally managed to assemble a new 52V battery pack, so I think this weekend I will make a first try. I hope everything will work with this setup!
Attachments
1.JPG
1.JPG (76.72 KiB) Viewed 6420 times
2.JPG
2.JPG (36.47 KiB) Viewed 6420 times
3.JPG
3.JPG (39.23 KiB) Viewed 6420 times
4.JPG
4.JPG (30.9 KiB) Viewed 6420 times

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 17 2018 1:57pm

I tried today to connect the battery, and there is Error 07H on the screen, like in the photo. Maybe someone knows about any way of getting rid of it without lowering the voltage?
Attachments
Przechwytywanie.PNG
Przechwytywanie.PNG (238.22 KiB) Viewed 6395 times

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » May 17 2018 2:50pm

Bummer. Normally it takes 62-63v to trigger that error. Do you know what voltage is the trigger point?

It should be possible to drop the voltage a little going to the display unit but keep the voltage to the main wires at a higher level. I tested this on a BBSHD. We first need to know how much the voltage needs to drop to make things happy. Then make a "voltage dropper" circuit that goes in series with the brown wire going to the display. Just getting to the brown wire is a pain since it's buried in the potting, but it's not impossible.
"One test is worth a thousand opinions"

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 17 2018 5:48pm

Thank you for the reply Fechter. That sounds like it might work, but under the error there is another line at the screen, which makes me think that it could be controller firmware. It says "Controller Report", and to be honest, I have no idea if it really could be the case.

However, can I get to the brown cable other way than in the controller? Maybe like in the cable going to the screen?

Now I am trying to discharge the battery a little to see if it would work with the voltage from range of 13s battery.

Also, I found an yt video showing reprogramming the microcontroller inside BBSHD, using some external files with firmware (theoretically, it would be possible to upload a firmware of BBSHD to my BBS01B if they both have HZXT SZZ9 boards with IAP15F2K61S2, correct?). Maybe someone knows if is possible to get them somehow? The video

https://www.youtube.com/watch?v=6fvJVz30LU8

Thank you very much again!

Tats   1 kW

1 kW
Posts: 419
Joined: Apr 17 2014 9:51pm
Location: NOR Perth, worlds best kept secret, Australia

Re: BBS01B 36V 250W - trying with higher voltage

Post by Tats » May 17 2018 11:17pm

I tried my 36v BBS02 with 52v - over voltage error. I have the programking cable and there does not appear any way to change the HVC :(

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 18 2018 7:07am

Tats, I think that is because you also has 36v controller, so it is probably programmed the same way like mine. If there was a way of reprogramming it (or letting the controller to see dumped voltage, like 26V instead of 52V), then I think it would work. The question is how to do this. The app that most of the people uses to change only some of the values is not the only tool to reprogram the microcontroller, I think. While watching the video from the previous link, I found a software for reprogramming microcontrollers called STC-ISP. I think you could wipe clean the whole flash memory using it, as well as writing a completely new/different one. I think I should take a closer look on that.

Fechter, I don't know how high the trigger point for high voltage protection is, because it seems that it cannot be checked even using dedicated programming cable with the well known bafang software. However, I just left the battery running with the screen to let it discharge slowly and I hope to see when the error message will disappear.

In case that it is not possible to reprogram HV trigger point, I would like to check which new controller I can buy to use my 52V battery. I will start researching the forum, but maybe someone could give me some hint about this? Best if it could work with DPC-14 screen. I would be grateful!

I am also wondering if there is any open source firmware to use for BLDC motor controllers. I will try to take a look on that also.

EDIT:
I just found a way how to check if the error 07H is caused by the display itself or the entire controller. If it is a screen, then it should work fine without it. Do you think this is a reliable test?
Attachments
5.JPG
5.JPG (49.02 KiB) Viewed 6338 times

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » May 18 2018 8:40am

I believe the overvoltage detection happens in the controller, but not sure about that. I don't know of any way to change the firmware in the controller. There is a spot on the board for the ISP, but have not ever seen the software. Bafang won't let it out.

Putting a jumper across the pins on the display cable will turn the controller on, but it will default to PAS level 1 and you would have no way to change it. If the voltage detection happens in the controller, this wouldn't help anyway.

Pack voltage goes from the controller to the display unit on the brown wire and the power on/off switch is in the display. You can intercept the brown wire anywhere along this path. The display unit is glued together, so might be hard to take apart without damaging. One option is to find an extension cable for the display and cut that up so you don't have to cut into any of the original wiring. Cutting into the existing display cable is also an option. If you are careful, you can remove the jacket from a spot without cutting the wires inside, then only cut the brown wire.

There are several versions of "voltage dropper" circuits. The simplest is just a big TVS diode (or several in series) to get the desired drop. This will need to dissipate heat, so depending on the drop we can do the math on how hot it will get. There is a low voltage cutoff point in the software too, so the dropper should be set for the least amount of drop that doesn't trigger the over voltage error.

Using the voltage dropper will make the battery meter even less useful than it already is. A separate voltmeter or CA might be a good idea. I like the TK15 Coulomb Meter (around $25 on eBay).
"One test is worth a thousand opinions"

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 21 2018 4:07am

Thank you Fechter for all the information.

I think I will just go for the TVS diode, as this sounds the simpliest. For now, I am still waiting for the voltage to go below trigger point, but after that I may need some help in deciding which diode will be the right one. About the low voltage protection from the screen, I hope I won't need it, as my battery has its own BMS for 14s battery, so I think I can rely on that.

Now the battery is 54.2V and the error is still there. I will let you know when the motor starts spinning.

Bombus   10 µW

10 µW
Posts: 5
Joined: Aug 03 2016 4:46am
Location: Wellington New Zealand

Re: BBS01B 36V 250W - trying with higher voltage

Post by Bombus » May 24 2018 4:47am

Hi Wizzeros,
I had the same issue. I found that the cadence on my 350 watt was too slow on 36 volts. I added a additional cell making it 39.6 volts nominal run on a bypass switch. If it was fully charge the high voltage cut the motor out. on 90% charge it was OK.
In the end just bought a 48 volt controller, replacing the 36 volt controller and run it on 52 volts, now it is a different beast.
It is the controller that controls the high voltage cut out.
Hope this helps

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » May 30 2018 2:01am

Hi Bombus,

Thank you for the information. With Fechter support, I just tried to connect some diode to lower the voltage for the screen, and it worked! Hovewer, I just tried it yesterday and limited the current, just to be safe. this weekend I want to check if I can use the full potential of my battery using the 36V controller, as I saw some settings of it, like throttle voltage, not going high enough. I think the max seting is 50V, while I would like to use 58,8V. I will try to investigate.

However, could you tell me which controller did you buy? Is it from BBS01 or BBS02, but 48V version? Is there a 48V of BBS01B controller that fits straight from the box? I think I read somewhere that the BBS02 controller won't fit to BBS01B. I would be grateful for such information!

Edit: As I read about the throttle voltage, I realize that it is the voltage only given by the thumb throttle device, not the voltage going to the motor. Also, according to some web pages, it is best to set it between 1,1V-4,2V. I keep investigating other things.
Last edited by Wizzeros on Jun 26 2018 9:43am, edited 1 time in total.

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » Jun 05 2018 9:18am

Hello everyone,

I finally mounted TVS diode within the brown cable, and it works! There is no error and the bike is riding, yes! The screen shows now 43V when the battery is fully charged. I checked the trigger point with some resistors, and 45V was already with an error, so iI think the TVS diode is quite well chosen (ON Semiconductor P6KE15CA TVS-diode DO-15 14.3 V 600 W). I lowered LVC to 28V using the programming cable, and it seems that this is the minimum value possible. I think it could be lower though (I also have BMS within the battery pack, which did not triggered LVC).

On saturday I made around 85 kilometers on one charge (around 53 miles), with some pedaling, and at the end, when I tried to ride with more power, it started to cut off the power for several seconds, then bringing it back again. The voltage seen on the display went below 28V indeed every time before the cut off. On lower assist levels (with less current consumption) it was still working ok, but I was not certain about when it could cut off for good. I checked the battery voltage at home, and it was still 46,7V, so according to my calculations, it could be discharged by 8.9V more. I wonder if this is normal characteristic of discharge?

2.7V * 14S = 37.8V
46.7V - 37.8V = 8.9V

I know that during discharging, battery voltage drops, but can you tell me what level of voltage is in your batteries after you decide not to ride anymore?

Anyway, I also checked the max speed and it seems to be around 55kph on flat surface, which is a little more than 34mph. I am very happy about that, considering that this is just BBS01 motor! Later, I will try to provide more detailed bicycle specification, as I know performance depends on many factors.

Thank you for all the help! Now I am able to commute, at least :)

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » Jun 05 2018 2:22pm

Glad it worked out. Your bike goes faster than my BBSHD.

Your low voltage cutoff is probably not bad as it can damage the cells if you go too low. I notice the sag under load gets worse as the pack gets more discharged. I generally stop when my pack is reading around 46v at rest but I also use a TK-15 amp-hour meter to really tell where the pack is at.

If you really want to take the pack lower, you could use a fixed voltage regulator instead of the TVS diode but this would make the display voltmeter read a constant value (useless). There is also a way to make a proportional voltage regulator so the display reads exactly 10/14 of the input but this is quite a bit mored complex.
"One test is worth a thousand opinions"

Tats   1 kW

1 kW
Posts: 419
Joined: Apr 17 2014 9:51pm
Location: NOR Perth, worlds best kept secret, Australia

Re: BBS01B 36V 250W - trying with higher voltage

Post by Tats » Jun 18 2018 11:17pm

Interesting - are you saying that all that was required is the TVS-diode and some resistors to bring the voltage down between the controller and display and this prevents the HVC error?

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » Jun 19 2018 8:26am

Tats wrote:
Jun 18 2018 11:17pm
Interesting - are you saying that all that was required is the TVS-diode and some resistors to bring the voltage down between the controller and display and this prevents the HVC error?
Just a TVS diode. At higher voltage differentials, the TVS diode will dissipate more heat, so you have to pay attention to cooling. Current is roughly 40mA so you can do the math. The TVS diode can be inserted anywhere between the display and the controller.
"One test is worth a thousand opinions"

Drum   100 W

100 W
Posts: 257
Joined: Dec 29 2013 1:20pm
Location: Otaki New Zealand

Re: BBS01B 36V 250W - trying with higher voltage

Post by Drum » Jun 19 2018 6:07pm

Wizzeros, one possible solution to your issue with Low Volt Cutoff being activated early with the TVS diode in line would be to install a switch to bypass the diode. When the pack is full charged the switch can be open, letting the diode drop the voltage, then close the switch when the pack is half discharged, so there would not be any voltage drop, returning the battery indicator and LVC to their proper function.
Obviously this has disadvantages.. another piece of hardware, another thing to remember.. but could be an easy way of getting your system working both at fully-charged and nearly empty voltages.

User avatar
fechter   100 GW

100 GW
Posts: 14648
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: BBS01B 36V 250W - trying with higher voltage

Post by fechter » Jun 20 2018 8:30am

It would be possible to use a fixed voltage regulator instead of a TVS diode. This would keep the voltage going to the display constant regardless of the pack voltage. The downside of this would be the battery meter and LVC would be useless.

It would also be possible to make a proportional voltage regulator that would output a fixed percentage of the pack voltage. This would be ideal as the stock battery meter would function normally along with the low battery cutoff. This circuit would be a bit more complex and require a connection to the ground wire as well as being inserted in line with the display power.
"One test is worth a thousand opinions"

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » Jun 26 2018 4:10am

Hello everyone,

I have been testing my bike for a couple of weeks, and it is great! I have been playing with the options (programming cable), also relubricated the IGH (Nexus 7), but the result is that it is a little slower now, around 48-50kph max speed. I also killed IGH's ball bearings, so currently waiting for the parcel with new ones. They were already very old, so I am not sure if the high torque is the cause. After replacing bearings, inflating tires to the max, and setting up the software better, I will check the max speed again, but to be honest, I will use it very rarely, because 40kph is totally enough for commuting. It is very stable 40kph, like rock solid. Of course, to elongate the range, I am cruising 25-35kph most of the time, using PAS. It is really like cruise control! I like it. Everyone does, even those skeptical ones (most of people), after first ride, change their minds.

Tats, yes, just TVS diode, like Fechter adviced. Works great. I got used to lower voltage displaying on the screen, and I still have clue how much energy I have left. And it is quite accurate. Of course, when it drains energy, the voltage drops then, but when you know this, you can rely on the voltage measurement while not draining the power from the battery.

Drum, your idea is a next step which I will take, i think, but for now, the TVS diode is almost perfectly dimensioned, so that I don't know if i really need the bypass. Also, when the battery is 46-47V, the LVC already works, so I would still need another TVS diode to dump at least 3-4V from it. Anyways, the cell can go down to 2,7V, right? It makes the voltage of 14s battery, like 37,8V. that could give me quite a lot of extra range, but not discharging it lower than 46V will elongate the battery life. So I think I will end up with a switch, switching between healthy discharge level and emergency one :) On the "healthy" mode, I already did 85km on the first long trip, still with some power left, and never had to ride that far again.

Let me repair the IGH and I will let you know about more details!
Last edited by Wizzeros on Jul 05 2018 2:55am, edited 1 time in total.

Wizzeros   1 mW

1 mW
Posts: 18
Joined: Apr 25 2018 11:09am

Re: BBS01B 36V 250W - trying with higher voltage

Post by Wizzeros » Jul 02 2018 8:01am

I would like to post my bicycle's specs for everyone looking for such information in the future. I hope it will help some people in their research:

Bicycle: Giant Adelaide (city bike)
Frame size: L (57-58cm)
Frame type: Hard tail
Front suspension: RST 802-7
Wheel diameter: 28”
Tyre size imperial: 28 x 1 5/8 x 1 3/8
Tyre size metric: 700x35C
Brakes: Roller brakes, Shimano Nexave BR-IM50 (front and rear)
Bike’s overall weight: 28.5kg
Motor: Bafang BBS01B 36V 250W
Cells: 56x Panasonic NCR18650B 3400mAh Li-Ion
Battery pack: 14s4p 52V 13.6Ah in Hailong shark case
Fully charged max wattage (at 58.8V and 20A): 1176W
Almost empty max wattage (at 37.8V and 20A): 756W
Front sprocket (crank side): 48T
Rear sprocket (IGH side): 18T
Sprockets’ ratio: 2.67
Rear Gearset: Shimano Nexus SG-7R46 Inter-7 (7 gears with ratios: 1- 0.632; 2- 0.741; 3- 0.843; 4- 0.989; 5- 1.145; 6- 1.335; 7- 1.545)
Extra info:
My weight: ~80kg
Max speed (fully charged): 53.5kph
Range: I think up to ~100km (didn't try to go so far yet on one charge)
More aggressive ride range: ~50km
BBS01's internal gearing ratio: 1:21.9
Brake sensors: front only
How HVC was disabled: Battery voltage that is seen by the display is damped using TVS diode (ON Semiconductor P6KE15CA TVS-diode DO-15 14.3 V 600 W) to suppress controller’s overvoltage error (HVC). Actual voltage that goes to the motor is not affected, therefore it has more power than it thinks.
Lights: Front hub dyno for front light, rear light with batteries. Light sensor - both auto-on when dark.
Bafang config tool settings: see attachments
Attachments
bafang1.JPG
Basic tab
bafang1.JPG (87.8 KiB) Viewed 5755 times
bafang2.JPG
Pedal assist tab
bafang2.JPG (74.91 KiB) Viewed 5755 times
bafang3.JPG
Throttle handle tab
bafang3.JPG (61.2 KiB) Viewed 5755 times
img1.jpg
img1.jpg (200.2 KiB) Viewed 5750 times
img2.jpg
img2.jpg (153.58 KiB) Viewed 5750 times

Post Reply