Bafang G062 48V display problem

[anaka]

Hi everybody i'm new on the forum and i have a problem with my bike that is driving me crazy

some weeks ago my display died with no apparent reason and no way to bring it back to life
i had a APT 750C display, very good guy

i bought a replacement and when i did connect it to the bike i saw that it was reading my battery a little too low, it was reading 25% of charge only
i did fully charge my battery but it was already full....basically the display reads the battery with a voltage much lower than the effective one

i measured it with multimeter and i have 54 to 56 volts at the battery and as well to the connector of the display the voltage remains the same
but the display keep saying 44V or similar

i shipped back the display and bought a APT 860C that is more performant and possibly better model (it should resist to water more as well)
when i installed this new model i got exactly the same results, the battery is around 54V, the connector to the display gives the same 54V and the display reads only 44V

this means that after some Km riding the display cuts out the energy to the motor because of the battery protection for low voltage, when the battery is full

now how this is possible??
the APT guys can't explain why, we are in touch but they say it's a motor controller problem

my controller is: Bafang CR S107.1000.SN.U 3.0 F227E1V6250028

can someone help me to solve this situation?
i did test 3 different displays and they behave all the same way

 

[DieselTech]

Hi everybody i'm new on the forum and i have a problem with my bike that is driving me crazy

some weeks ago my display died with no apparent reason and no way to bring it back to life
i had a APT 750C display, very good guy

i bought a replacement and when i did connect it to the bike i saw that it was reading my battery a little too low, it was reading 25% of charge only
i did fully charge my battery but it was already full....basically the display reads the battery with a voltage much lower than the effective one

i measured it with multimeter and i have 54 to 56 volts at the battery and as well to the connector of the display the voltage remains the same
but the display keep saying 44V or similar

i shipped back the display and bought a APT 860C that is more performant and possibly better model (it should resist to water more as well)
when i installed this new model i got exactly the same results, the battery is around 54V, the connector to the display gives the same 54V and the display reads only 44V

this means that after some Km riding the display cuts out the energy to the motor because of the battery protection for low voltage, when the battery is full

now how this is possible??
the APT guys can't explain why, we are in touch but they say it's a motor controller problem

my controller is: Bafang CR S107.1000.SN.U 3.0 F227E1V6250028

can someone help me to solve this situation?
i did test 3 different displays and they behave all the same way

Did you set the new display up for your bikes battery voltage? Most of these displays I have seen, has a setting to set your battery voltage, so it displays the correct voltage/battery level.

 

[anaka]

yes i did all the settings correctly, wheel size, battery voltage, all done well

 

[Annieolnie]

Do you have an extra julet plug that can mimic what would be on your display? I'm thinking if one of the pins in your wiring harness is crushed or pushed back your multimeter might read it but the display plug might not read it fully. You could put a julet into the wiring harness and then read the voltages from the bare wires on the other side of the plug to see if the plug connections are working. What is your bike? Is it easy to get a new wiring harness? If your wiring harness is the female side, it could have easily been pushed too far in. This is just my best guess. One of these might help you test:.

 

[anaka]

that's a good idea, i can use my old broken display to check that

 

[anaka]

ok just did the test....i connected the old display after to open it's shell

checking the wires with multimeter directly on the electric board i still get the 54V so the big connection cable from the controller has no problems

so now it remains only the controller and the display

i'm wondering....could be in any way the battery responsible of this? i really don't think so but at this point anything can be involved

anyway the battery did ever work super fine and keeps generating power as for the first day

 

[Annieolnie]

This has got me stumped. Could you tell us what model controller you have and does it have a means of doing a complete reset?

 

[anaka]

here you can see my controller
it would be really good to know how to reset it if possible

Bafang CR S107.1000.SN.U 3.0 F227E1V6250028

 

[m@Robertson]

That is a Bafang brand controller, which is really unusual. They are very seldom used, but are a part of the 'new generation' of Bafang products that often include, among other things, the lack of ability to inter-operate with aftermarket products.

https://bafang-e.com/en/oem-area/components/component/controller/cr-s3071000fc
I'm willing to bet money it is indeed the controller, and the reason its a problem is because there is something quasi-proprietary in the mix here. What does your battery connection to the controller look like? Is it just two wires to, say, Anderson plugs or an XT60/XT90? Or is it instead another HIGO? What do your controller plugs look like? Are they round or do they have a pointy end to make them sort of a rounded triangle?

I think there's a good chance your controller is demanding a genuine Bafang-branded display. A 3rd-party APT750 may look the same, but internally it is not at all uncommon for a manufacturer to shift the protocols around a bit to stop you from using 3rd party products. In fact, this is exactly the reason Bafang is killing off their UART BBSHD and BBS02 motors, finally. The (very thin) story behind the discontinuation is they need to enforce absolute adherence to products being used with their motors to help them limit their liability.

EDIT: Is yours one of the Bafang Smile batteries?

 

[m@Robertson]

Whoops I should have read the link to the Bafang OEM site I gave to you above more carefully. I just read the specs and saw the protocol they are using.

The controller is CAN bus. Not UART. That tears it. You are almost certainly required to use a matching Bafang-branded part. Possibly you also need to have it dialed in 'officially' with the BESST tool, which typically means a Bafang dealer has to do it because only they have the dealer login to handshake with the Bafang server.

The HIGOs @Annieolnie is showing you are the ones most of us know by heart that are UART bus.

I don't see the 750C on the Bafang OEM site, but thats not unusual. Its often incomplete.

This is why the Bafang CAN bus is so roundly hated by the DIY community, and we all stuck to the UART motors. Even the Ultras. For years after the CAN versions came out.

 

[anaka]

hi m@ i think i have to tell the story of my conversion kit more in detail

i bought it on amazon as full kit, so motor controller battery and display
the controller is what you see above in the pictures, the display was the 750C rebranded windmile or similar
the battery was a big 20Ah from a china producer with no name....it died after 2 years only

now i have a RadPower battery 14Ah 48V and it's connected with the 2 classica wires only
the controller has 2 wires only as power input and they are the classic rounded ones, like banana connectors, with a transparent green rubber around for insulation

so the kit starts as not pure bafang and did work fine for 2 years, one year ago the battery died, some weeks ago the display died
november is a bad month for my bike maybe

 

[m@Robertson]

Well, Bafang has a reputation for building ANYTHING you want so long as the order is big enough (that is how Rad Power Bikes got a motor that is labeled 500w for anyone else to be engraved on the casing as 750w and to have the big plug for the 750w motor put onto it).

So this would be one of those, then. Your model number came up to that oem page so its that controller according to the official line, but obviously different.

If it were me I'd get rid of the controller. Since your motor is a G062, that means its got the big round plug, right? And you have a 30a peak controller. You can buy a KT controller that outputs 35a peak and it will behave MUCH better than what you have now. Attempts to fix this problem will be just shots in the dark, and you have already bought two displays trying to fix the problem so you are in deeper than you should be as it is.

For your hub, which is top of the Bafang line, I would

1. Write off the display cost but hope you can get it to work down the road (very doubtful).
2. Buy a KT controller with the big plug which matches your motor, and that has the 'waterproof' plugs (which are the round HIGO/Julets). Electrobikeworld sells a 35a sine wave one but it uses non standard throttle and PAS connectors. Instead, there is a 30a sinewave model. Here's one on Ebay. The price is about right for a sinewave unit and I know... $105 is a lot.
3. Re-use what you can of your existing parts. Since you have a Bafang controller, and most everyone is working to do Bafang compatibility on their parts, you have a good shot at this. But its not guaranteed.
4. Buy a 1T4 wiring harness for that controller whether you need it or not. Chances are good you will, and if your existing controller needs 1 wire for every peripheral, this will simplify your wiring significantly. Buying it in advance is insurance against the possibility that the existing harness will not work.
5. Do a different display. The Color version that is fully featured is the KT-LCD8H. The black-and-white version is the venerable always-faithful KT-LCD3. I personally prefer the minimalist KT-LCD4 which is also dirt cheap at around $30. Note that KT displays give you access to a couple of dozen parameters that make the bike very configurable, and a much better performer. Particularly with the simulated torque assist on the PAS.

I think it likely you will not want to do this and keep trying to fix it... until you give up and this remains the only remaining option. I think your only other alternative is to contact the original kit seller and see if they have another of their displays. If its an Amazon kit that is about as sketchy as it gets in terms of confidence that you can get it done successfully.

 

[Annieolnie]

Thank you M@. The dreaded CAN bus controller would've had me going in circles for forever.

 

[anaka]

ok M@ i will document on the components that you are mentioning
in the meantime googling online i saw the VESC controllers that are more or less same price but fully programmable and support Bluetooth with android APP

is this a good option as well? in this case which display to use with?

 

[m@Robertson]

If you go VESC this is a few levels up the ladder in terms of degree of difficulty. A KT controller is essentially plug and play. I can give you the few motor parameters needed (or you can figure them out for yourself via the Bafang motor specs page). A VESC controller on the other hand is a blank slate. Highly configurable, but you go from a software user to a software programmer. Not really, but its a good analogy to the amount of work you are going to be doing one vs. the other. If you are just trying to get your 2-wheeled transportation back up and running, going 'experimental' is the wrong choice. A VESC controller makes a lot more sense on a from-scratch, high power build with something esoteric. Resurrecting an old ebike kit that you need to get running again... not so much.

On the other hand, if you love a project and are not scared of tinkering with this sort of thing, it might be fun for you. Some place like Endless Sphere is more likely to be able to have members who can do a deep dive on VESC and get you meaningful answers to any question.

 

[anaka]

thanks M@ yes i like to do stuff with wires and soldering, i'm watching some interesting tutorials on how to pair the vesc with the G062 and they look really cool....plus i don't need any display...i can use the mobile that is a great plus and makes all cheaper as well

i'll keep studying both the solutions in those days then will decide

 

[m@Robertson]

thanks M@ yes i like to do stuff with wires and soldering, i'm watching some interesting tutorials on how to pair the vesc with the G062 and they look really cool....plus i don't need any display...i can use the mobile that is a great plus and makes all cheaper as well

i'll keep studying both the solutions in those days then will decide

I'm curious as to what it is you are looking at with regard to VESC and the G062. I have a few G060's and a brace of G020's - one of which is getting put into use in about a month - and I'd be curious to see what you are looking at.

One of my bikes has 2 G060's front+rear that used to be a daily driver but is now semi-retired. It has a 30ah battery that can handle a 90a continuous power draw from both G060's, which each have 35a controllers, dual throttles and synch'd 2-wheel PAS. For a bike I don't use anymore, it would make a fun platform for a new project.

 

[anaka]

well i have a kind of monster bike with fat tires and air suspensions both sides and i use it to carry filming equipment into the woods
the system works well but i did ever feel that the bike was under powered due to standard esc, btw i was happy cause i don't need speed more than stability

now that i realized that i have to change both display and esc i'd like to choose a solution that is less china style and more open to fixing by myself
plus if i can avoid the display using my mobile and save money at the same time it would be great

that's why VESC looks so interesting, i have all the skills to convert to vesc so why not...it sounds the perfect solution
the only thing i fear is the stability in time...hope to don't have to recalibrate the system very often due to opensource but basing on my experience with open platforms this shouldn't happen

 

[HumanPerson]

Do it and keep us informed with pictures!

 

[anaka]

about yout KT controller and display solutions....i'm interested as well to know more....if i find a solution premade that saves time and costs almost the same it can be good as well to save time

i'm from europe and it looks like i can find those models here as well so i'd like to know the name of the ESC that you would suggest for the G062 1000W 30A motor i have, i found the display already