Need Advice on how to proceed

[sungod1]

BG: Tale of Typical (Danger WOT)

Late last year, I bought a folding ebike from Engwe... Typical Stuff, seemed to have good reviews. First ebike and had not had any bike for years since my last bike was stolen. Anyway... the thing worked fine for me... No really issues.. Other then it being pretty fast and finding PAS crazy if you have never used it. One day I went to check it over because some family wanted check it out and ride it on a holiday. Well... it would not start... I put in a ticket about it soon after think I was going to have to time set aside to trouble shoot blah .. blah. I got the time to mess with it.. I was stuck with 3 issues I could not isolate, the controller, display, the hub motor. I told them I need a controller and display because it is really hard to know with the display being a single point of failure what was the root cause and if any of the parts where not need I would ship them back. So.. to make it short after about a week of sending pictures to them of voltages I had already check, They agreed it was they display and the controller.

After two days of nothing... I asked them when to expect tracking. Well no USA distrubtor has the parts so... they are going to come for China. Which is 2-3 weeks if you have the parts and a good day.

So I am stuck ... Well.. I want to ride this thing. I need a controller... and a backup display which I wanted to have before I learned that you could bypass by shorting pin1 and pin2 but you need an extension higo to use as a jumper. I am not sure that would always work as the bike defaulted to pas 0 if I recall.

Anyway,.. I think you know what I discovered about the total shit fest the "market" really is.. Yeah.. the bike might not be worth putting money into...but, I am not bothered by that... The really issue is. I have no specs on most of the bike electric systems but what helpful owners have discovered and shared with others. Battery pack is good but I have zero info about the BMS and Motor is assumed functional as well but no specs on it.

So.. I was thinking, I could get a vesc and just hook up the motor my thumb throttle and my brake cut offs and just use an old cell with BT to run the tools app on. And that would get me by until the parts come in... if they every really do.

Then I see thing are not so simple, the need for breakout boards.. odd voltages and resistors to kill noise on the signal wire so the throttle will not not go all suicide mode on you. The PAS drama... the drama of open source and the issue of bad actors bending the specs on their products, the likes of which I have not seen since dealing with VARs and Software vendors.

So the goal is simple... get this bike up and running, not hack up the BS wiring too bad so OEM restore if the parts ever come might be an options.

Any advice any Ideas... Good Plan Bad plan... drop but 20 and punt?

 

[amberwolf]

By "would not start", what specifically and exactly were the symptoms, compared to normal operation? The exact symptoms may help us determine which part is more likely at fault so you can replace it.

Assuming the controller is the problem: What is the current limit on the controller, and the voltage of the system? We'll need those at a minimum to recommend a replacement controller.

If you don't know the controller current limit, then the label on the controller may list this if you post a clear picture of it. If it does not, then a link to the page the bike you have is sold from may have enough information on it to help us figure that out. If you don't have that, then at least stating the complete specifications for the bike, as they were in whatever ad you saw for it that got you to buy it, may help. If you don't have that, then a good clear picture of the overall bike, and then of the individual parts (controller, all sides, display, front and back, motor, both sides and any markings between the flanges, battery, all sides) with something else in the picture that shows scale (ruler, soda can, etc) may help us determine approximate power ratings.

The battery or it's charger should have a DC voltage listed on them somewhere, if you don't know the system voltage; a good clear picture of their labels may help us determine that.


BTW, if you also want a display with a new controller, you'll want to get that with the controller as a kit to be sure it is compatible (there are a number of different incompatible comm protocols; displays that look similar and even have same connectors won't work on controllers except those made to work with them, and vice-versa; even different firmware versions on cont/disp may make them incompatible).

If you don't want to have to use a display, you can get controllers that don't need one (but they dont' generally have adjustable levels for PAS or throttle, etc).

Depending on the connectors used for your existing controls, battery, motor, etc, you may need to buy matching connectors and splice them onto the new controller to connect it all up without modifying the stuff already on the bike, as there isn't a "standard" for that either. A number of controllers come with Julet / Higo round waterproof connectors, but they dont' always match what an OEM ebike uses either in number of pins or wiring. Otherwise you may have to cut connectors off controller, motor, controls, battery, etc., directly splice the wiring together or use your own preferred connectors.

 

[sungod1]

bike https://engwe-bikes.com/products/engine-pro

They said the replacements were approved .... KD986 display and controller ZNZK Rated 48v Max 18a Rated 6a
Throttle voltage 1.2-4.4v

This one might be deprecated because of EBS regen issues the 2022 updated model have a bigger battery pack and NO REGEN.

The issue with this is the down time I have no reason to doubt fulfillment but it could take months for them to arrive.
When support runs out.. this bike will be impossible to get parts for.

 

[sungod1]

Sorry.... to assume. So, This bike can only be started with a remote connected to the back of the display. So if the display is broken or stolen, you are dead in the water and stuck unless you know of the bypass... but you need the extension cable to make the jump unless the cable was cut or broken at that point just hack that up for the jump.

The other thing is you better hope you turned the power key off and the caps were flat when the display got broken. from what i understand there is 36v or 48v on the VCC pin so if it grounds it could damage the display or the controller or both

 

[amberwolf]

bike https://engwe-bikes.com/products/engine-pro

They said the replacements were approved .... KD986 display and controller ZNZK Rated 48v Max 18a Rated 6a
Throttle voltage 1.2-4.4v

Ok. That link shows electrical specs of

- 750W Powerful Motor
- 48V 12.8Ah/16Ah Lithium Removable Battery
- Cruise Control
- Color LCD Display

Presumably the two different capacities listed are just options. The pictures state its' a 614wh battery, which is about 12ah.

The Max 18a means that it can support that much current for a few seconds at a time, with time to cool off between (presumably it would shutdown after those seconds if that kind of load continued longer, but some dont' and instead just blow up from overload/overheating, and that could be the case here, given that you say they dont' support the regen on the newer version (which also produces high momentary loads on the system that can cause failures if it's not properly designed), though it's more common for regen to not be available because geared hubmotors that are physically incapable of regen are more common than direct drive (DD) hubmotors (which are always capable of it.

48v * 6a = is only 288w, so if it's really a 750w motor, then the controller they use is severely underpowered for it, probably so they can use a really cheap battery that has a very low c-rate (and or is made of recycled cells that may no longer be capable of supporting their original specs). Tyipcally controllers of this type are very small, smaller than a pack of cigarettes, so that they can fit inside frames or small encasements, or even inside battery packs or battery mounts. I'd guess your controller is mounted inside the frame just in front of the seat, like the very similar looking CeMoto folding bikes do.

To get 750w at 48v, it would take about 15-16a continous capability from the controller and battery. If your battery can actually handle it, you could then get a 15-16a controller, though that may not fit on your bike in the original spot. You'd likely have to mount this to the outside of the frame somewhere. (hose clamps, zipties, etc), and run its' cables externally to the frame as well, except for the battery wires which will have to thru the hole in the frame the original controller likely has just above the top of the shock, so you can connect them to the back of the bladed battery connector that's liekly in the front of that half of the folding section of the frame.

If you don't need the extra power, just a small 6-8a controller may still fit inside the frame where the original was.

If you don't want to do cutting and splicing of wires, you'll want to look at the connectors the original uses, and post clear pictures of them, so we can help you get a controller that may have the correct plugs and wiring order (might still not; cant' tell till you try them) to make it more plug-and-play.


FWIW, it's unlikely that the motor is a DD hubmotor, given the size in the pictures, and if it is a geared hubmotor then it is unlikely to be capable of regen regardless of what the controller can do, as they almost all have one-way clutches inside to make them easier to pedal without power.

If yours does actually brake the bike without the mechanical brakes, then it is probably not the same as the motor pictured at that link, and providing actual pictures of what you have may help us help you find a more appropriate controller for it (or at least figure out what you really have so you can find matching parts later when you need them).



You havent' specified if you want a display or not, what connectors everything has on the actual bike you have there, or anything else about how you want the bike to work with the replacement controller, so until that's provided it's difficult to recommend any specific controller.

When support runs out.. this bike will be impossible to get parts for.

Unfortunately true for just about any ebike product, whether it's a complete system or just part of one, regardless of manufacturer, if you need an exact replacement part to just drop in, plug and play. Not even that uncommon for them to change what's used in the middle of a run of the same model, so that parts are not interchangeable between what should be identical bikes/systems, and then to have no replacement parts for the systems at all, ever, even "under warranty". (Bafang does this all the time, without telling anyone, even their dealers!).

That's also typically true of products in general, regardless of type, for the average consumer that doesn't know how to source alternate solutions.

 

[sungod1]

I could be wrong but full charge 54v x 18a = 972w?
So you think the BMS is 18a discharge?

Only markings on the hub.. it has a bafang style connection 9pin for phase and hall and a strange white wire that I am told is speed sensor? What little I know these are only safe for up to 30a?

Yea the control is a 6mosfet little thing with mixed connect type SM2 connectors bullets for the phase wires and Deans for main I think that is what they are called but that is what I use to use for my RC stuff. Jammed in that little space where is gets no cooling.

It just all looks so under powered but I thought it moved out and had no issue going u bridges and bike trail overpasses But I am not too heavy a rider...

I remember with you hit full throttle the battery level would drop on the display until you let off that is what is call ripple current?

 

[amberwolf]

I could be wrong but full charge 54v x 18a = 972w?

Yes, theoretically, but in reality you'll never see that; the battery will sag at that current so it won't provide 54v, so you use the average voltage of 48v to figure voltage, since it will be closest to that for most of the discharge curve.

The 18a current will only be a few seconds at a time since the controller is rated 18a "max", it will only sustain 6a continuous, so that is the rating you would use for current draw.

So a power calculation for what the controller can continuously provide is only 48v * 6a, or a little over 250w.

The manufacturer may use the highest possible numbers for their sales and marketing info, but in reality you won't get those. Same thing for their range claims. Nobody uses realistic numbers for any of that stuff, which is a shame, because it too-often leaves the buyer dissatisfied and they may then assume all electric stuff will be as bad as what they bought (relative to what they expected out of it), so they go back to gas powered stuff (whcih they probably never even look at power, mileage and range figures for because it's gas and they "know" it will work).

So you think the BMS is 18a discharge?

I have no way of knowing what the BMS can do; that's in the battery and there are zero specs for the battery other than it's average voltage (48v) and it's capacity (12.6ah, 614.4wh, or 16ah (no wh stated) for the upgraded battery). To know what the BMS can do would require testing at your end, which could be destructive if the BMS does not have overcurrent or overheat protection.

What I think the cells can do without much voltage sag is probably between 6a and 12a, (or 0.5c and 1c, since it's a 12ah pack), just based on what various ebike packs I've read of here, and personally experienced, can handle.

20220227_151909[1].jpg
Only markings on the hub..

guessing based on the width of the motor and size relative to the gear cluster, that is a geared hub, which wouldn't do regen even if your controller supports it because of the internal freewheel. You can check for this by placing the bike upside down, motor wheel offground, powered off, and grab the tire with your hand, to turn the wheel forwards, then backwards. There will be the same resistance both ways for a DD hub, and less going forwards with a geared freewheeling hub than going backwards.

it has a bafang style connection 9pin for phase and hall and a strange white wire that I am told is speed sensor?

What do you mean by "bafang style connection"? There are a few types I've seen on bafang-branded motors. The most common is the Julet/higo type, like the one shown here
https://ebikes.ca/learn/connectors.html#HiGoMainSignal
from this page:
https://ebikes.ca/learn/connectors.html
but there are others.

The speed sensor is needed because a geared hub freewheels internally when not powered, so it cant' use the hall sensors in the motor to read wheel speed, as they won't get any readings unless the motor is spinning fast enough to be driving the wheel. Any other time there will be no (valid) wheel speed reading. So the white wire goes to a different sensor that detects magnets (usually six) embedded in the side cover, which always spins with the wheel.

What little I know these are only safe for up to 30a?

It says 750w in the number on there, so if like most ebike hubmotors that is it's continous rating (not peak or max), then if run at 48v, it would only be guaranteed safe to run it at 750 / 48 = 15.625a, assuming it's able to spin at full speed and isnt' bogged down to slow speed but at full power like climbing a steep hill or something (that can quickly overheat motors).

Yea the control is a 6mosfet little thing with mixed connect type SM2 connectors bullets for the phase wires and Deans for main I think that is what they are called but that is what I use to use for my RC stuff.

Deans typically look like this
https://www.amazon.com/Hobbypark-T-Plug-Connectors-Battery-Electric/dp/B01C8NWJ78
is that what you mean? If so, it's easy enough to get a matching connector to change in for the one on any new controller you buy.

By "SM2" do you mean the JST-SM connectors like these?
https://ebikes.ca/learn/connectors.html#JST-SM
that's what is on the CeMoto bike similar to yours for all the signals. If so, you can also easily enough get those and change all the signal connectors on a new controller to them, matching up the wiring at the same time. You also have to buy the proper crimper for them (they're not solder contacts, and the wrong crimper can make them either not fit in their housings, or damage the wire in crimping, or leave a loose crimp with poor or no connection).

Problem is that there's no standard wiring pattern to them so you'll need to trace out and measure stuff to find out which connectors do what, and what pins on each are which signals or supply voltages or grounds.

Jammed in that little space where is gets no cooling.

Pretty normal for regular-power-level OEM bikes; it's one reason they use such small ratings on those little controllers; there just isn't enough cooling to do much more than that. Some of them are bolted to the frames, whcih then provide some conduction of heat, but most just rattle around loose in there like the CeMoto's does, so there's nothing but stale air to slowly convect radiated heat away from the controller to the frame, which can then conduct and radiate heat away (same problem hubmotors have in cooling off).

It's not an issue for their normal intended usage; when overtaxed then it can be.

It just all looks so under powered but I thought it moved out and had no issue going u bridges and bike trail overpasses But I am not too heavy a rider...

If it works for your situation, it's not underpowered.

I remember with you hit full throttle the battery level would drop on the display until you let off that is what is call ripple current?

Voltage sag.

It's caused by the cells being unable to supply all the current that is being asked for because of their internal resistance, so the voltage drops across that resistance. Sometimes it's a connection or wiring issue, but that's rare--all the cheap cells (and batteries made from them) will have this problem, and so will any other pack made from cells inadequate to the demands placed on them.

Even a good pack will still have some voltage sag when placed in a situation where more current is pulled from it than it can handle; the way to prevent that is to overspec the pack to easily be able to supply more current than it will ever be asked to do. (this also means that it will probably still be able to supply what it's asked for even when it's old and decrepit).


Ripple current is the current in a capacitor when the voltage of the power bus it is on fluctuates (usualy in some pattern), creating current in the capacitor itself and it's leads.

 

[sungod1]

So could I set up a sensor input for the white speed sensor in Vesc Tool to plug that into?
I think I have all of the connections sorted to have at least basic control but that one,

I have on old I phone S5 I can run as a display if, If get a blue tooth board.

Looks like Just need to de-pin a few connections and get some connectors for what ever connections a Vesc that is a good fit for my shitty BMS and noname re-warp cells is using. Again the pitch on the pins looks odd on some of these. Maybe leave myself some head room to get a battery rebuild in that OEM box. I could get a 52V pack for the rack in the back if I feel the need for speed.

Stock on the old display I could hit 28-32mph But I never check it in GPS. But it went plenty fast so I doubt I ever go to 52v.

 

[amberwolf]

So could I set up a sensor input for the white speed sensor in Vesc Tool to plug that into?

Sorry, no idea, never used a vesc. Maybe someone who has can step in here and reply to that part.

Looks like Just need to de-pin a few connections and get some connectors for what ever connections a Vesc that is a good fit

Altering the orignal connectors on the bike may prevent you from using the original controller / etc that is coming (theoretically) to replace the possibly failed parts, assuming you ever want to use them. (at least, until you replace the connectors on either the bike or the replacement parts).

for my shitty BMS and noname re-warp cells is using.

Couple of things:
--I don't know the VESC, but does it actually connect to your BMS? (very very few controllers do; Adappto was the only one I know of for sure, but it actually has it's own, rather than connecting to an existing one) If so, you'll have to disassemble your battery, and alter the folding joint area of the bike (at least the panels between controller and battery compartments), to pass the wiring for these connections thru, and then deal with trying not to damage the wiring while refolding the bike each time. Could be problematic.

--Have you disassembled your battery? If not, you don't know if the BMS is shitty, or what cells are in there (much less their source or condition). If you have disassembled it, hopefully you did testing on it to verify it's operation both before and after the disassembly, to be sure it works as you need it to. If you haven't disassembled it, I don't recommend doing so unless you have a specific problem with it that requires disassembly to repair it.

If the battery is like the CeMoto's, it is pouch cells glued together and glued into the casing, so disassembly would very likely destroy it's ability to be reinstalled into the frame (and may well destroy the cells themselves, making the battery useless).

(I'm mostly trying to point out it's best not to draw conclusions before verifying and testing things, for anything you haven't already done that for. ).

Again the pitch on the pins looks odd on some of these.

Some of what? You're not posting any pictures, or giving any details of what specifically your'e talking about.

 

[sungod1]

Behold!!!! I think this configuration is know as a silverfish.... on most aili sights.



I have pulled the trigger on a flipsky vesc and a BT card...

F75100 75V 100A Single ESC Based on VESC For Electric Skateboard / Scooter / Ebike Speed Controller

now it is a race to see what parts get here first, the new or the old.

The vesc does not communicate with the bms... I was saying shitty as is seems it might only do 18a

You have been a big help... but I am still kind of stumped by this hub.. it does have some drag forward some reverse. I never really noticed it being hard to peddle on PAS0... as far as I can remember regen would work on PAS1 and PAS2 only and you have to be going pretty fast for it to kick in but you could go down a bridge that you would be doing like 40mph down abd just letting the E braking keep you under control. and you could seed -watts on the sceen when is was back feeding the battery pack.

Now I just need a small connector and pin set and get this ipad unlocked and a few more odds and ends and I am will be ready to tin and pin.

 

[amberwolf]

I was saying shitty as is seems it might only do 18a

What tests have you performed to determine that limit?

Or have you disassembled the battery to get to the BMS and found a label on it that directly or indirectly provided this info?

(There's no information from the bike manufacturer that gives any kind of BMS capability, so without doing one of those, you cannot know or even really guess what the limits of the BMS are. It's pretty important when troubleshooting or upgrading a system to actually test or find specific information before making determinations about what you have or what problems might exist (sometimes you can't find out and have to guess, but it's a last resort), and if you are working with others on it it's important to state specifically what info you have and preferably how you found it so they can properly help. It also helps if you provide complete information when talking about things, or answering questions when asked; without all the available information, it's difficult or impossible for others to provide the proper help.)



Also note that 18a is not "shitty" unless it comes with a motorcycle or some other high-power system that needs more than that. For your system, even if the BMS is limited to 18a, the controller and rest of system can't draw more than that, so it doesn't need to be any better, and would then be rated "just right" for the system.

You have been a big help... but I am still kind of stumped by this hub.. it does have some drag forward some reverse. I never really noticed it being hard to peddle on PAS0... as far as I can remember regen would work on PAS1 and PAS2 only and you have to be going pretty fast for it to kick in but you could go down a bridge that you would be doing like 40mph down abd just letting the E braking keep you under control. and you could seed -watts on the sceen when is was back feeding the battery pack.

Then that means it is actually doing regen, and that must mean your hubmotor does not have a freewheeling clutch inside; there have been a very few geared hubmotors that don't (Grin's GMAC is still in production; I have an old Fusin 350w, and others have popped up now and then).

It coudl also be a DD hub and not geared, but that's not very likely given it's very small diameter.

Now I just need a small connector and pin set and get this ipad unlocked and a few more odds and ends and I am will be ready to tin and pin.

What ipad? You haven't mentioned one before or included any pictures of one.

 

[sungod1]

What ipad? You haven't mentioned one before or included any pictures of one.

Indeed...
An Ipad is far to big to put on the cell phone holder and I have yet to verify the IOS version of vesc tool is in the beta builds bundle.
I have an old Iphone I could use as well. I would like to have USB charge port on the bike
Things I am still unclear about.

• the nature of the USB port on the controller

• the type of connectors on this model

• When I will get my hands on any parts

I am kind of stuck until I get my mits on the vesc. I dumped some volts out of my battery pack to a table lamp to get down under the voltage that the bms would allow (I don't the jargon for this) charging on the dc port and I topped it back off with the charger. Just to verify that something works.

I guess I should start thinking about the best way to test and train the controller to my hub, battery pack and IO stuff safely, with the limited amount of stuff I have.

I would think testing is needed and not to assume any of this works? A low power smoke test before going full battery pack output?

You asked about this Vesc and BMC communication and I have no idea, this is not a reference board and features could be lacking.

I am not sure that is even part of the current hardware spec.

I did watched V man himself, showing off some up coming stuff and he reads specs from every cell in a battery pack via a BMS and that exposed it for output to just about anywhere, but prototype hardware or software or both, no idea.

SO.. That would make this thing an amazing bench tool all by itself. Anyone who builds packs or salvages cells would want that kind of data. A person with a multimeter would take hrs to get that data by hand. I am sure large scale operations already have solutions in house and maybe it is common knowledge to e-bike builders.. but I was like WOW

So... error logs and scantools for your ebike? Yes Please!! Right now we can not get consensus on connectors.

The kind of stuff he was doing with his "Vesc platform" is 10K miles away from what you need for electric skate board.. and I am not sure how much cross over it gets with robotics and RC hobbies but yea.

TBH right now I am more excited about the potential here than I am about fixing my bike.