Controller question

[Sappho1949]

I have a Bafang bbs02 48v 750w, with UART protocol. I need a new controller, having trouble finding one specific to the UART protocol. Can the controller from a bbs02 motor with CAN protocol be used as a replacement for the motor that I have with UART protocol? The new versions of the controller all have connections for a headlamp, which my motor doesn’t have, as it seems to be an older version. It was purchased new from Bafang around 2016 or 2017. Any help would be appreciated!

 

[harryS]

Here you go. Website says it's in stock.

https://www.johnnynerdout.com/product-page/bbs02-replacement-controller

 

[RunForTheHills]

No, the canbus won't work with your display. But it doesn't seem that hard to find a UART controller. This one says it will work with BBS02's newer than 2015. You don't have to use the light connector. https://www.amazon.com/BAFANG-Contr...8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

 

[PedalUma]

I have only used a light kit once in the last eight or nine years. What I do is chop the light connector, strip off 5mm of outer insulation, pull the three wires back, and seal it with marine grade 1/4" heat shrink. It makes it neat and prevents a battery draining short. On those motors there is no good way to completely hide it. Maybe a slim zip tie around the entire base of the wires at the controller to prevent it from flopping. Some motors have a small hidden compartment with a cover plate for things like that. The second photo is a BBS02 build. The weird wire to the left is the dropper.

 

[Sappho1949]

No, the canbus won't work with your display. But it doesn't seem that hard to find a UART controller. This one says it will work with BBS02's newer than 2015. You don't have to use the light connector. https://www.amazon.com/BAFANG-Controller-BBS02B-Connector-Sensor/dp/B0B5CX11RX/ref=sr_1_1_sspa?adgrpid=185181074566&dib=eyJ2IjoiMSJ9.spunZQBey0PEQXiC34VfGcT2kyanfRrof7AJmRh4neFZI0XZhQksaSKY-3dgPZzZCjBZEzxyg2HLmi3JhPNW-ITPnRh9Ik9ixttgaPqWt-MXcjsQuKrkX5-U3qs57FTmyS2vDySyR071-VLrKcYpBLViAEDAAlRXvtRDRRT9sAaamJeWcMFnoYU4k8o44A4NdoY06URQxsFy1ARCkDSwUOQvD7dpJmn089L6HPrQKkk.ZU7F6gitTzfMvf_SzpB2hdy361x3AYvbVUtoMGcKC-I&dib_tag=se&hvadid=779658733888&hvdev=c&hvexpln=0&hvlocphy=9061321&hvnetw=g&hvocijid=8856691201474717868--&hvqmt=e&hvrand=8856691201474717868&hvtargid=kwd-299219630829&hydadcr=2425_13459543_2133693&keywords=bafang+bbs02+controller&mcid=6554d2c2f2313c61baa9e6bd90512cb9&qid=1769541893&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

Thank you for the info., very useful.

 

[JL0256]

You generally can’t swap a CAN controller onto a UART BBS02—the protocol (and usually the wiring/display system) won’t match, so it won’t communicate or run correctly.The “headlight” lead on newer UART controllers is normal and optional. Your older motor can still work fine with a newer UART controller; just leave that headlight wire unused.What you need is a 48V 750W BBS02/BBS02B UART controller that matches your existing harness/display connectors. If the plugs don’t match, you may need the matching harness (and possibly display) as a set.

 

[PCeBiker]

The weird wire to the left is the dropper.

Cool !!!
Dropper Forks !!??
I didn't know that there was such a thing ?

I've got a remote lockout for my air forks, but I didn't connect it.

I got to thinking about it, and I could use my remote speed lock just like a dropper seat post.

I would just have to lock my forks when they are compressed to "drop" them, but that's kinda hard to do.

It's easy to do with a dropper seat post because the post only has enough spring tension to lift the seat but not the rider.

It would take a pretty big push on my handlebars to compress my forks, but at least with the remote lock-out, I'd have both arms and hand pushing on the handlebars together to get a bit of compression before I lock it out.

PS,.. Are dropper forks compatible with my new UART BBS02B motor or will I need the CANBUS version?

 

[PCeBiker]

I have a Bafang bbs02 48v 750w, with UART protocol.

I just bought the same motor and had to spend $100 more for the UART version.

They're getting hard to find now, but I knew that I didn't want a CANBUS motor.

 

[PCeBiker]

Here you go. Website says it's in stock.

@harryS
I'm just wondering if it's possible to hook up a KT controller and display to a BBS02B?

My new motor is UART, but that's probably irrelevant?

Would I just gut the old controller housing and splice into the wiring harness?

 

[PedalUma]

That wire is for the seatpost. See that phone bag with the llama aps? That is where the connectors are tucked. I made a small slice and shoved them in. In other words I cheated to make it appear clean. It is still a BBS02 with all the wires and connectors.

 

[PCeBiker]

That wire is for the seatpost.

So you're saying that this is NOT a remote lock-out for the forks?

It's the brake line?
On the wrong side of the forks?

What the Hell??


And this is a dropper seat post??

Does it pivot forwards or backwards when it drops?

 

[harryS]

@harryS
I'm just wondering if it's possible to hook up a KT controller and display to a BBS02B? My new motor is UART, but that's probably irrelevant? Would I just gut the old controller housing and splice into the wiring harness?

The motor has three phases and Hall sensors, so you could spin it with any controller. The wires for the cadence sensor also come out. The KT controller would give you wacky speed readings. When coasting, it would use wheel sensor and wheel size. Should be correct there. Under power, you can only set the P1 number for one gearing combo.

I wonder if the much touted current based system used by the KT controller feels any different in a mid drive.

 

[PCeBiker]

The motor has three phases and Hall sensors, so you could spin it with any controller. The wires for the cadence sensor also come out.

I've already had the motor up and running with just the display, throttle, and a battery connected with no PAS or speed sensor.

The KT controller would give you wacky speed readings. When coasting, it would use wheel sensor and wheel size. Should be correct there. Under power, you can only set the P1 number for one gearing combo.

The speedometer was reading Zero, and I wouldn't bother connecting the speed sensor, but I need to Not go over 32 kph, so I have to connect it to limit my top speed.

I'd have to figure out what gear gets my motor at ~100 rpms at ~32 kph and choose that one.

Maybe I'll set P1 to my 44T chainring and my 34T freewheel so that I get full power at 5 or 10 mph to use during Hurricane season.

I wonder if the much touted current based system used by the KT controller feels any different in a mid drive.

Bafang BBS motors have Always has a choice of current based or speed based.

I bet that you could adjust the KT power delivery curve (throttle power for me) to feel just like a Bafang mid-drive or vice versa?

I haven't ridden my ebike yet, but I did reduce first throttle gear (or whatever Bafang calls it?) to ~4% from 10% start power.

10% was too much power for first gear start power.

I don't want to Slam my gears or break anything, but I'm not going to totally neuter my ebike.
I'm still gunna dump up to 30 amps into the motor for short bursts, (my batteries have 30 amp BMS's) and that's over 1500 watts.

My hub drive motor controller tops out at ~18 amps but they do have a 30 amp KT controller for less than $100

So for two hundred bucks I can replace both of my controllers and toss 60 amps total at up to 54.6 volts into my E-bike!!

That would be Fun !!

 

[PCeBiker]

You don't have to use the light connector.

@RunForTheHills ,..
My BBS02B came with the light output connector.
Is what @PedalUma said true in that a short circuit simply drains the battery?

My KT controller has a separate daughter board inside the controller to power the headlight.
It's rated 0.2 amps at battery voltage (10 watts) and a short circuit will blow up the daughter board.

Does my BBS02B simply drain the battery slowly with the light output shorted?

 

[RunForTheHills]

Not usually. If you shorted it with a resister or some kind of load, maybe. The BMS could shut the battery down. If you have a fuse inline, that may blow. Most likely, with thin wires used for lights, the wire will melt or that board could be damaged. That's assuming the light function is turned on though.

 

[RunForTheHills]

Back when I was in college, I had a VW Bug. The battery was under the back seat on the driver's side. I had dinner fork slip under the seat and short the battery to the frame. It melted the fork and burned a hole in the seat.

 

[PedalUma]

Okay, it was a while ago. That could be the fork lock remote. The main thing is that it is not a regular thing. It is an odd extra wire I couldn't hide.