How To, 50A BBSHD Controller Mod

Some pictures of my mosfet swap out. The new IRFB4110 from is rated 100V. Found very good information about it here https://electricbike-blog.com/bbs02-controller-mods/

Very important to not have used the controller for some time before soldering shunts, mosfets and so on, or there will be shortcuts and sparks since the caps can hold electricity for a long time. To get rid of the old mosfets I found out the best way to do it without any damage is to wiggle them carefully back and forth one by one, until the legs of them snapped, and then clear the holes afterwards. I cut the legs of the new mosfets at the right length, screwed them on slightly on the heatplate, inserted them all in the PCB and solder all the legs. As pointed out before, soldering them to the PCB without attached to the heatplate will make it impossible to screw them on later (the hole of the mosfets and the ones in the heatplate will not line up). Now I am only waiting for the caps to arrive. :)
 

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Epyon said:
A big thanks to you guys. I swapped out my shunt resistors and capacitors.

A bit off topic, but does anyone here know where the ROM/EPROM chip that contains the firmware is located on the PCB? Perhaps it is possible to replace that chip with the one on my faulty controller with the old firmware to make trottle override PAS. :?: :?
 
BBSHD processor chip.jpg

Well, it's right there. It would be very challenging to replace the chip. I don't think you could get a new chip from anywhere either.
What would be easier would be to re-flash the firmware on the chip, but that is something only Bafang has and they are not likely to give you a copy. Possibly you could send them the controller and have them re-flash the firmware and send it back, but I doubt they would be willing to do that.
 
fechter said:
BBSHD processor chip.jpg

Well, it's right there. It would be very challenging to replace the chip. I don't think you could get a new chip from anywhere either.
What would be easier would be to re-flash the firmware on the chip, but that is something only Bafang has and they are not likely to give you a copy. Possibly you could send them the controller and have them re-flash the firmware and send it back, but I doubt they would be willing to do that.

Several resellers have the firmware, perhaps someone will pony up...
 
fechter said:
BBSHD processor chip.jpg

Well, it's right there. It would be very challenging to replace the chip. I don't think you could get a new chip from anywhere either.
What would be easier would be to re-flash the firmware on the chip, but that is something only Bafang has and they are not likely to give you a copy. Possibly you could send them the controller and have them re-flash the firmware and send it back, but I doubt they would be willing to do that.

Thanks for the info! Seems hard to replace that chip with the old one, but so is a re-flash. How can it be done? Bth, my caps has arrived, but as E-mil has pointed out, the small board on the PCB (for the 6V Headlamp cable), make the 1000µF impossible to fit. Is it possible to remove the small board from the pcb to make it work?? (The old controllers didn´t have these "headlamp cards" but the PCB had holes prepared for it.)
 
To re flash the firmware, you need an ISP interface (sort of easy) and the software (not so easy).
Generally you can re-write the firmware, but there is no way to read it from the chip. This is to keep people from copying or hacking it. The software part would need to come from Bafang.
 
Daxxie said:
How to do this 50A mod to a Bafang Ultra drive?
Should be easier. Controller is not potted.
I have a standard one that I would like to upgrade.

It's not so easy. Just getting the motor apart can be a challenge. The shunt is located on the controller board next to where the negative battery terminal attaches. This is under the mezzanine board, which needs to be removed to get access. Due to the board being recessed in the housing, I think you'd need to completely pull the board out to tweak the shunt. Use some thermal grease when you put the board back into the housing.

Shunt location 1.jpg
 
It's not so easy. Just getting the motor apart can be a challenge.

Well I have a Ludicrous version but I also bought a standard Ultra.
It looks pretty different from your picture.
This is how my Ludicrous version looks.

bf6.jpg

bf2.jpg
 
Yes, it does look a lot different, but similar.

The shunt is located here:

Ultra Motor Controller - Shunt Location.jpg

It looks pretty easy to attack. It's 5 milliohms, so with some math you can figure out what to place in parallel with it to get what you want. To double the current limit, use another 5 mOhm. I've simply stacked another one on top before and it worked OK. It will get hot if run near the limit for long. Ideally, you'd want to place two side by side so they are both in contact with the board, but maybe not worth the work. You could also completely remove the stock one and replace it with a different value. I got a bunch of 3 milliohm ones from Mouser that are the same physical size.

That board will require a lot of heat to solder on the shunts because it's aluminum. Use a big iron.

And I have never found a datasheet for those FETs. Mystery part number. EZ85NF12
 
" I got a bunch of 3 milliohm ones from Mouser that are the same physical size."

For the Bafang Ultra, to swap out the 5mOhm and replace it with a 3mOhm, can you please tell me what is the part # from Mouser?

Is it Mouser #: 660-PSIDTEB3L00F
https://www.mouser.com/ProductDetail/KOA-Speer/PSIDTEB3L00F?qs=sGAEpiMZZMtlleCFQhR%2fzdSx607k3xJbQqATOmV1HfQ%3d

Thanks!
 
dalysea said:
" I got a bunch of 3 milliohm ones from Mouser that are the same physical size."

For the Bafang Ultra, to swap out the 5mOhm and replace it with a 3mOhm, can you please tell me what is the part # from Mouser?

Is it Mouser #: 660-PSIDTEB3L00F
https://www.mouser.com/ProductDetail/KOA-Speer/PSIDTEB3L00F?qs=sGAEpiMZZMtlleCFQhR%2fzdSx607k3xJbQqATOmV1HfQ%3d

Thanks!

I think the ones I got are these:
https://www.mouser.com/ProductDetail/Bourns/CRE2512-FZ-R003E-3?qs=sGAEpiMZZMtlleCFQhR%2fzSJLNHPYVlBI%252ba1P%2f%2fAfFR8%252bPjReNe2kZA%3d%3d

Physical size is 2512.
 
A question, how are the 50A BBSHD mods holding up? I saw on FB that one had darkened the motor wires (insulation changed color) and destroyed the small gear. Not suddenly, but over time. How common is this? Does it happen even at 30A or are we pushing a bit into getting it too hot? Any other issues folks are seeing on these, or are they pretty reliable??
 
Sounds like excessive motor temperature. I haven't tried 50A, but at 30A you can certainly overheat the motor if you try hard.
 
Sorry guys, don't want to go too much off-topic here.

But I just received another Bafang Ultra wich I bought of Aliexpress from a "reliable" company.
Price was quite good.
It arrived today and I opened it up immediately to compare it with my Luna Ludicrous version.
The Ludicrous is a 1.3 version and the new one I got from China has "version 1.5" stamped on it.
Controller looks a bit different but I noticed the Hall sensors were not connected.
The connector is missing? WTF I don't think this will work.

bf13.jpg

bf9.jpg

bf17.jpg

bf183.jpg



And to my surprise the "cheap" chinese version has a steel gear, where the Ludi has a nylon gear.

bf15.jpg

bf16.jpg
 
We should have a separate thread for the Ultra motor.

I heard some versions of these used a sensorless controller, which could explain the hall sensors not being used. At some point in time they switched to the metal gears also. Seems Bafang keeps making changes, which maybe indicates the earlier designs had some problems.
 
fechter said:
I heard some versions of these used a sensorless controller, which could explain the hall sensors not being used. Seems Bafang keeps making changes, which maybe indicates the earlier designs had some problems.

Well I didn't hook it up yet.
So maybe it could work without this connection?
Gonna try that.

I heard from Luna they are currently not offering the Ludicrous version anymore.
"Too many reliability issues from users"
 
fechter said:
We should have a separate thread for the Ultra motor.

I heard some versions of these used a sensorless controller, which could explain the hall sensors not being used. At some point in time they switched to the metal gears also. Seems Bafang keeps making changes, which maybe indicates the earlier designs had some problems.
Changes without data or notification. Argh! And forget about tying changes to serial number, double ARGH!
 
Sorry for the interference, but isn't "Ludicrous" version just a Luna internal name for a controller where they switched out the shunt (and maybe also replaced aluminum case IIRC)?
 
racingame said:
Sorry for the interference, but isn't "Ludicrous" version just a Luna internal name for a controller where they switched out the shunt (and maybe also replaced aluminum case IIRC)?

Yes. It may also have a steel gear instead of the plastic one.
 
Does anyone sell Ludicrous type controllers or provide a service to upgrade an original? I'd try the modification myself, but that would be an expensive waste if I screwed it up,LOL!
 
Just wondering would the display show the correct amount of watts being used? running the bbshd @ 52v nominal / 45 amps (shunt mod)
 
Daveograph said:
Just wondering would the display show the correct amount of watts being used? running the bbshd @ 52v nominal / 45 amps (shunt mod)

No. If the shunt is modified, the current on the display will read lower than actual. If you are getting an actual 45A, then the meter on the display will probably show 30A. 30A will always be the highest reading.
 
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