Looking for a well-documented 36V, 250W controller

MilesFinn

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Queens, USA
Newbie with ebikes, but not with electronics. I want to find a controller for a front hub motor (36V, 250W; Bafang) that comes with good documentation. Can I expect to get good documentation if i buy from Amazon?
Thanks all.
 
What specific documentation do you require?

Most don't even have a good external wiring diagram, and that's what most people would like to have, but some would like other info, sometimes including schematics, code, etc., which is simply not available for anything other than opensource projects, AFAIK (but there are a few of those).
 
Is this one of those great little bafang g311 motors? If it is, it is probably the most documented motor there is, some 250 plus post on this site including thorough testing by Grinn tech.
 
Most (90%) E-Bike components are produced in China.

My experience with any Chinese produced products indicate that there is no such thing as good Chinese documentation. Even if there was not a problem in translating from Chinese to Chinglish to English, there is always the problem where the manufacturer changes the products and neglects to tell the drop-ship vendor (who has likely never seen the product that they are selling). This includes simple things like common fasteners.

The exception are some proprietary (read as expensive) devices produced by vendors such as Bosch or Grin Technologies. In some cases (i.e. Bosch) there may be excellent documentation somewhere but it is not available to the consumer.

Example: I recently purchased some "Pre Bulbed Rivet Nut" inserts on Amazon (common name PlusNuts or CrossNuts).
https://www.amazon.com/dp/B09GXQ26V2
Common 1/4-20 rivet nut inserts require a tool with 1/2 to 5/8 of an inch protrusion on the mandrels. These require a full inch protrusion on the mandrels. I wrote the vendor asking what the proper tool for installing their product was. A week later the vendor still has no clue.

MilesFinn said:
Can I expect to get good documentation if i buy from Amazon?
Answer: Definite "No"


(For inquiring minds: the best hand tool is is an Astro Pneumatic 1450 but there are some less expensive alternatives)
 
I was hoping for a document laying out the controller's cables, including the purpose of each (e.g., + 5V, gnd, or "connect to speed potentiometer") , its color, and the connector type.

After a few hours of work, I got a Chinese controller, one that seems popular on Amazon, to work. But I've got to think that that there must be a lot of these controllers that were purchased but never successfully wired.

Is there a standard for displays, or do you need to buy a display that the controller vendor promotes?

This whole industry is in serious need of standardization.
 
MilesFinn said:
This whole industry is in serious need of standardization.

Haha, that's cute.

Figuring it out for yourself is somewhat more feasible.
 
MilesFinn said:
I was hoping for a document laying out the controller's cables, including the purpose of each (e.g., + 5V, gnd, or "connect to speed potentiometer") , its color, and the connector type.

Very very few give this info. Grin Tech at http://ebikes.ca has it for most of their stuff. It's the only seller I've got any experience with that does. EM3EV may also do this; I haven't checked them in a long while.

Some controller manufacturers like Kelly provide this kind of information, but they are the manufacturer...they are one of the few that will sell to individuals. Most only sell to OEMs; you can buy their stuff (Sevcon, ASI, Mobipus, etc) from third parties but you're pretty much completely on your own at that point (no support, no documentation, software, passwords, etc; they only deal with OEMs on that stuff, not individuals).

But I've got to think that that there must be a lot of these controllers that were purchased but never successfully wired.
That's almost certainly true. :( Certainly seen it happen enough here on ES.

Is there a standard for displays, or do you need to buy a display that the controller vendor promotes?
THere are no shared standards. Not even a guarantee that the same brand of display works on the same brand of controller; they may have different firmware versions, or even not be designed to work with each other.

There is a sort of standard in that most of the controller/display sets communicate via a serial RX/TX two wire bus, and use battery voltage and ground from the controller, and control anohter battery-voltage-level keyswitch-ignition (KSI) line back to the controller to power it on remotely from the handlebar controls. They even often use the Julet / Higo 5-pin "green" connector for the waterproof cabling sets, and may even use the same wiring of that connector.

But the serial protocol may be different, and even if it is the same, the data being sent will be different for different controllers, displays, firmware versions, etc etc.

Then there are different sellers of the same brand, who may have custom versions of them, that don't even have the same settings available in the menus, or the setting means something different in one seller's version vs another.

Then there's the stuff that comes on OEM bikes, sometimes developed by that OEM, sometimes not, that only works with itself.

Etc.

There are some controllers that work with multiple models of display, and vice-versa. But to be sure what will or won't, you'd probably have to search ES to find out if someone successfully used Controller X from Vendor A with Display Y from Vendor B. (it could make a difference where it's purchased from because some sellers do have their own versions of things).


Then there are the several Open Source FirmWare (OSFW) projects here on ES, to replace the software on various controllers and displays to *make* them compatible, and to give features the original didn't have (but which the hardware supports).



This whole industry is in serious need of standardization.
That is almost certainly never going to happen, at least partly for similar reasons that Ford parts don't fit Hondas, or Kia parts fit BMWs, etc.
 
Standards are necessary for many industries to grow. There are standards on wheels & valves (https://www.parktool.com/blog/repair-help/tire-wheel-and-inner-tube-fit-standards) , BB (https://www.parktool.com/blog/repair-help/bottom-bracket-standards-and-terminology) etc. Also this ISO standard: https://www.bike-eu.com/8946/new-iso-standard-for-bicycles-implemented

It's the same for cell phones, where e.g., the 3GPP standards are vital.
 
MilesFinn said:
Standards are necessary for many industries to grow. There are standards on wheels & valves (https://www.parktool.com/blog/repair-help/tire-wheel-and-inner-tube-fit-standards) , BB (https://www.parktool.com/blog/repair-help/bottom-bracket-standards-and-terminology) etc. Also this ISO standard: https://www.bike-eu.com/8946/new-iso-standard-for-bicycles-implemented

It's the same for cell phones, where e.g., the 3GPP standards are vital.
LOL .... Tell the Chinese that ... they will likely reply,
"So sorry disappoint you. We'll look into this and get back to you. Your understanding would be grateful."
 
MilesFinn said:
Standards are necessary for many industries to grow. There are standards on wheels & valves (https://www.parktool.com/blog/repair-help/tire-wheel-and-inner-tube-fit-standards) , BB (https://www.parktool.com/blog/repair-help/bottom-bracket-standards-and-terminology) etc. Also this ISO standard: https://www.bike-eu.com/8946/new-iso-standard-for-bicycles-implemented

It's the same for cell phones, where e.g., the 3GPP standards are vital.

If there was a need for the bikes to communicate with each other, there might eventually be a standard like that. But there's not.

What you see in ebike stuff is a bunch of competing companies that want you to buy just their stuff. So far the only "standards" any of them have widely adopted are bad things, like using the flatted-axle for torque transmission, with wires running thru a hollow axle, and various other really cheap ways of making ebike parts (like the typical extruded controller casing with FETs clamped to one side via a bar that doesn't sit flat against the side and thus has poor heat transfer, etc).

They have "sort of" adopted a color standard...yellow blue and green for the UVW phases and hall signals...but even within a company they don't use the same *order* of those wires on motors and controllers, so you can't even depend on wiring color to color (you just hope you get auto-learn function that works right).

Some other wiring color patterns tend to be used as well, such as red for positive voltages and black for grounds, but even that isn't universal--GoldenMotor, in one of their Magic Pie versions, decided to use black for battery positive, and red for ground. Eventually they started putting little stickers on them for + and -, after enough people blew up their new motors (with controller integrated inside) hooking them up...and eventually with some later version they finally went back to the way almost everyone else does it, with red for + and black for -.

But I wouldn't count on any particular thing being the same between any two pieces of equipment, even if they are from the same manufacturer, let alone same seller, or different manufacturers / sellers.

It's aggravating...but there's as much likelihood of it changing as there is of major operating system and software manufacturers listening to their users and making things actually usable and customizable to the way people actually need to use them, instead of having some marketing "genius" come up with some frocked-up idea of how things ought to work and then forcing that on everyone instead.
 
MilesFinn said:
Standards are necessary for many industries to grow.

Yet they are not necessary for you to hit the buy button, which is what the manufactureres care about. If you clicked on the buy, you clicked on reinforcing no standards.
 
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