Trouble with new Bafang Controller

[abbeswag]

Hi,

I have a Bafang M400 with a probably broken controller, so I ordered a replacement.
However, this bike is fitted with Enviolo Automatiq, and somehow the older controller had one more cable,
which the replacement controller does not, so I cannot plug in the Automatiq.

My question is, how would I power the Automatiq using the Bafang M400 controller? It needs a between 9V-55V power line,
and I just cannot find that much information. There are two loose cables from the controller, I think EB-BUS and maybe gear sensor?
Enviolo has an open-ended cable for sale, which means that it would be a matter of figuring out where to actually connect it and connect
the correct head.

The old controller came with a XTU30U-F cable

Thank you if you are able to help with this dilemma.

 

[abbeswag]

I was wrong, the free cables are the battery control cable and the gear shift cable. Is it hopeless?

If so, can it be solved using a battery? An XT30 battery, for instance.

 

[amberwolf]

Is your system supposed to automatically shift the gears in the Enviolo? If so, does your new controller have that function in the firmware, and the connection for the hardware?

If not, it may not work as it did before / as you want it to.

If you can add wiring to your new controller at it's battery input wires, you can wire up the open-ended Enviolo cable to these and whatever control inputs it requires, directly. If not, you could add the power wiring to the battery cabling (but you'll need to remember to disconnect or turn off the battery so it isn't being drained by the Enviolo when not in use).

 

[abbeswag]

I don't think they communicate, the XT30 cable seems to be only for power.

Connector: DC supply; socket; XT30; female; PIN: 4; for cable; black​

So it does not communicate data.
It does automatically shift, but this is independent from the controller if I understand it correctly.

Not sure how I would add wiring to the battery input wires, it is a regular direct connection with no extra cables.
If I have to connect it to the battery, could I buy a small external battery with a switch and use a slightly inferior solution?

Thanks for your reply!

 

[amberwolf]

If there's only battery power on there, then that greatly simplifies things.

By "battery input wires" I just mean the two main + and - wires on the controlelr board itself--you'd wire the power wires on the open-ended cable to that point.

You can certainly use a separate battery; just make sure it's capable of the current the shifter requires, and has enough capacity to last all the ride(s) you need it to. And don't forget to turn it off when not using it (or to recharge it when you need to), or it won't have (enough) capacity to do what you need it to.

 

[abbeswag]

Ah! But the controller is molded with silicon? and I would have to tear all that up to access the circuit, right? Then I could probably blook at how the other controller was wired, but I feel like there is a big risk of damaging it.

On aliexpress there is a small powerswitch for XT30, together with a battery could maybe power it. IT says 9.5-55V so a 14.8V battery could work.

 

[amberwolf]

If the controller is potted like that, it's probably a lot easier and safer to go with a separate battery. Just make sure the battery will run the shifter for the amount of time/range you need.

 

[abbeswag]

Thanks for your replies!

I contacted them and they said that one way they fix it on these controllers without cable is to either solder the old cable to the battery connector, or use a "crocodile clamp" (not sure english word for it), since the shifter can use the same voltage from the battery

 

[amberwolf]

a "crocodile clamp" (not sure english word for it),

The only thing comes to mind is alligator clip, but those aren't something you'd want to use while riding.


They're common for test equipment connections, but outside of controlled "lab" conditions they don't make great connections and there is risk of shorting things out or disconnecting them.


Sometimes the term you used is used for larger heavier duty versions of the same thing, like the ones you see on battery jumper cables for cars, or welder ground clamps, etc.

 

[abbeswag]

Hmm, well I'm not sure how to attach it. Soldering is not strong mechanically. Crimping? Attaching a small copper cable to the bullet connector from the battery.

 

[amberwolf]

. Soldering is not strong mechanically.

Depends on how you do it. There are a fair number of strong mechanical splices you can use that can then be soldered.

When I have to solder something that will be "hanging loose" or has to fit inside a small diameter, for wires with enough strands, what I usually do is slip some precut pieces of heatshrink over the wires and push them back as far as possible away from the end so they dont' shrink with the soldering heat. Then strip back 1/2" or so of insulation on eahc wire end. Then slightly fan all the strands out just a little bit, as if they were a brush, then insert the two wire ends into each other to intermingle the strands, then roll the strands together in a twist to get them mechanically tight as possible. Then solder using a high-wattage iron with a large chisel tip, so it very rapidly heats the joint and finishes the soldering so I can pull it away before the heat wicks up the wire and shrinks the HS.

Crimping is "better" as long as you have the right crimper for the splicing hardware, so that it crushes all the metal together into a single solid piece, cold-welding it all together. If you don't have that, then solder will be better, as it will be lower resistance and keep air and humidity out of the joint.

 

[abbeswag]

Well, that is truly a bummer. I managed to successfully switch controller and solder the cable.

After around 50-100km the initial error code 08 is back, hall sensor issue. It worked perfectly for the first part. Now it is broken again. What can I do?

I have found a replacement stator, but that seems to require recalibration which is not possible? You need to be a dealer to do this.
Is it possible to try to repair the stator of the motor? That the hall sensor cable is loose. Quite strange that it worked perfectly for quite a few km but then suddenly broke again.