DIY Newb FAQ?

E-HP

10 GW
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I think I've read through all of the stickies in the ebike forums, which provide great guidance. Yet, I see a lot a new folks getting into ebikes and posting questions that are not in the stickies, or are embedded somewhere among the existing stickies. Another observation is there are "graduating" ebikers that started with a simple kit and are moving on to another build from components, or are replacing components of their kits.

I'm wondering if there's a value to a DIY Newb FAQ, for both cases. I was thinking of a format like below. This is only showing the proposed format and some examples that may fit into it. Anyway, I thought maybe a Newb specific sticky might be helpful, and easy to find if titled that way. Is there an appetite here for something like this? I know all of this can be found with a search, but my other observation is that new folks don't use the tool as much, since you kind of need to know what to search for, or how to.

DIY Newb - General

The Parts of an Ebike System

Learn links Learn

Motor Concepts https://www.maxongroup.com/medias/sys_master/8798985748510.pdf

General: You cannot build an ebike that can go 50 MPH with a 60 mile range for "$1000" If you have a donor bike, you expect to build one with some combination of 20mph to 27mph top speed and 20 to 30 miles of range, for that investment, and speed vs. range is a trade off if your budget is fixed.

Batteries: If the deal is too good to be true, it is. A general rule, as of (Month/202#), for a pack made with name brand cell (Samsung/Sanyo/Panasonic/LG/Sony) $5 x the total number of cells in the pack is the minimum you should expect to pay. If the pack is made with generic Chinese "highest quality A grade cells", or similar description, you might expect to pay $3 x the total number.

Terminology: Most lithium ion packs use series of cells that make up the pack voltage; typically 36V, 48V, 52V, and 72V. Respectively, the number of corresponding series cells for those voltages are 10, 13, 14, and 20. The total pack capacity (amount of energy stored) is based on how many series groups are placed in parallel, and the capacity of each cell. Packs may be described by voltage and capacity (52V 15Ah) or by their component make up (for example 14S5P), which describes the number of series cells (14S) and the number of parallel group (5P). In the example below, lithium ion cells are used.​

"S", combined with the voltage specs for the cells used, will determine the voltage of the pack. So, 14S means 14 series cells, and in this example, each with a nominal voltage of 3.7V; 14 x 3.7 = 51.8, or a 52 volt pack.​
"P" is used to determine the current stored, and discharge capability of the pack. This again depends specs of the cells used (for example 3000mAh, with a discharge capability of 10A). So for a 5P pack, 3000mAh times the number of parallel groups (5 in this example); yields 5 x 3000 = 15000mAh or 15Ah stored. 5 x 10 = 50A discharge capability.​
So the example pack, using lithium ion cells, each with 3500mAh stored and 10A discharge capability, in a 14S5P configuration provides 15Ah with a 50A max output.​

Notes on battery safety:
  • Don't leave your bike charging while unattended. If you're leaving the house while charging, just set it on fire yourself when you leave, so you won't be surprised when you get home.
  • Don't ignore/dismiss/condone odd battery behavior. Don't make assumptions about the cause. It almost always will lead to issues if not addressed.
  • Don't assume charging will correct issues, other than balancing. Don't charge until the problem is properly diagnosed and corrected.
  • A battery shouldn't be getting hot while discharging, unless you are discharging near or above the rated output. The battery should be taken out of service until diagnosed. It could lead to a fire while riding.

Torque arms: If you choose a direct drive motor, and the kit doesn't include a torque arm, you should purchase one (or two). Don't cheap out on torque arms, they must fit tightly to be of use.
  • Threads:

  • Links:
    • Torque Arms on Hub Motor Bikes
      Grin makes high quality front and rear torque arms" Yes very good ones; here is their info page.

How far, how fast, etc.:

  • The Grin Motor Simulator is a great tool for determining how an ebike will perform based on the criteria entered; read of the instructions and start playing
  • Trip Simulator - Change the Input at the top left of graph to Google Maps and right click your start point and end point then move the route line to your desired route by dragging the line holding the left mouse button down.
eBike Lighting?
  • Very few aftermarket controller can support ebike lighing
List of controllers with lighting functions
  • KT controllers. Some have a lighting function that is controlled via the button pad. The output of the lighting connector is not sufficient to drive lights, but is sufficient for powering a relay to turn on the light. The output is limited to 70mA

......
...


Buy, Build?

Looking for an ebike conversion and not sure where to start?

Kits Vs Turnkey

DIY Newb - Kit builder (all components were purchased as part of a kit, battery may be purchased separately)

Tools:
Required: Hand tools for installation;
Optional/recommended (useful for troubleshooting): Digital Multimeter (DMM)
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DIY Newb - Component builder/upgrader (some or all components were not purchased as part of a kit)

Tools:
Required: Hand tools for installation; Digital Multimeter (DMM); soldering iron and/or crimpers; some installations may require connectors, heat shrink tubing, electrical tape, etc.
Optional: motor tester

Displays: Displays from different brands are not usually compatible. Displays that are the same brand as a controller don't guaranty compatibility, due to firmware variations, so purchasing the controller with the display will provide better assurance of compatibility. Some display manufacturers can support different controller brands, provided they are flashed with compatible firmware.

(work in progress)
Common displays and associated controller manufacturer (actual compatibility may be dictated by firmware):
SW900, S700, S800, S830, S866, S886, S890, S900, GD06, OMT-M3 - DC MOTO CONTROLLERBYLITHIUMBATTERY
KD21C, KD51C, KD59E, KD716, KD718 - Lishui
S866, S886, M5, M6T, LH100 - XLD (XunLiDa Electronics) BrainPower
LCD3, LCD4, LCD5, LCD7, LCD8H, LCD8S, LCD9, LCD10H, LED880 - Kunteng "KT"
C961, 500C, 750C, 800S, 860C, DPC-07, - Bafang

Displays and/or Controllers supported by Open Source Firmware
(custom/enhanced firmware developed by the user community):
Controllers -
KT controllers (certain models 0.25kW up to 5kW)
Lishui controllers (certain models)
Bafang BBS02, BBSHD mid drive internal controllers

Displays -
KT LCD3 used in conjunction with TSDZ2 mid drive
VLCD5-VLCD6-XH18, LCD3, 860C-850C-SW102 used in conjunction with TSDZ2 mid drive

Wiring: There are no wiring standards or wire color coding standards. If you are building from components, you cannot count on things working, just because you matched the wire colors on the connectors between devices. Use your DMM and realize that touching the wrong combination of wires can destroy electronics, instantaneously.

Common (not standard) controller connector wiring:
Throttle: 3 conductors - GND, 5V, signal

PAS (cadence): 3 conductors - GND, 5V, signal. Some systems (e.g. Grin), use a higher voltage input

Motor Phase: 3 large conductors. usually Blue, Yellow, Green

Motor Hall Sensor: 5 thin conductors. usually Blue, Yellow, Green (phase hall sensors), Red, Black (5V and GND powering hall sensors). If a sixth wire is present, usually White, it may be used for a speed sensor or temperature sensor (see motor specs).

Battery Power: 2 large conductors. usually Red (battery positive), Black (battery negative)

Brake (cutoff) switches (low brake):
  • 2 conductors for most generic Chinese controllers: N.O. switch (normally open when lever is not engaged) on the brake side connector; GND and signal (~5V via pull up resistor) on the controller side connector
  • 3 conductors: GND, signal (~5V), 5V. The 5V may or may not be used, but could provide power to a hall sensor, for variable braking/regen for instance.
Brake switches (high brake):
...
Self-learning: Usually two single wire connectors (male and female JST, often white), when connected runs an autotuning routine to determine the correct hall and phase wire combination. Once set, the wires are disconnected for normal operation. Note that in some cases, the self-learning routine may also set the battery voltage level for controllers that support more than one input voltage.

Wire Gauge Current Limits:
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Wheel Building:

Spoke Calculator - Online Spoke Calculator for Hubmotors and Ebikes

Chinglish to English translations (work in progress)
Electric Key Lock/Key Switch/Electric Door Lock/Ignition/Power Lock : Controller on/off; usually applying battery level voltage to the signal wire turns on the controller (frequently a thin orange conductor).
3 Position Switch/3 Speed Switch/3 Grade Switch/ : Controls 3 power or speed levels of the controller; the middle position is default
Learning/Self-study/Self-learning/Automatic Detection/Auto Learn : Jumper to enable automatic detection of motor hall/phase combination​
Throttle/Speed Governor/Accelerator/Turn Handle/ : Throttle Input​

Change Log:
05-03-21 - added general statement to General section and wiring to Component section. changed formatting, added torque arm links
05-27-21 - added 99t4 and markz contributions
07-01-22 - added links to Grin torque arm page
01/17-23 - added ebike lighting section
01-23-23 - added precautions with regards to batteries
03-19-23 - added link to motor concepts (provided by stancecoke on separate thread); started display model to manufacturer list
09-16-23 - added hyperlinks to display manuals
01-09-24 - added section on open source firmware
01-27-24 - added Chinglish to English translations section
02-09-24 - added self-learning notes in wiring section
02-18-24 - added wire gauge current limit link from slaphappygamer

Last observation: Most of the stickies appear to be threads that are made into stickies, so the information is scattered within the threads. It would be nice if when information is added by folks, that at the end the mods could consolidate into the main sections for easy access.

EDIT: Thinking about how a lot of members use translators when accessing the site, paragraphs probably don't work as well. I'm not sure, I don't use them much. Bullets are probably easier to understand.
 
Last edited:
Strongly agree. Many (most?) of the stickies have not been updated in years, some more than 5 years since!

Good to include solid info on TAs for DD hubs, but IMHO the language for torque arm quality could be even more forceful. Even with the "don't cheap out" language, some will still go ahead and get the Grin v.1 TA clone on Ali, etc. that is known problematical. Can we link to or show examples of the preferred quality specimens?

Another point to make in the "DIY Newb - General" section is to explain the un-reality of expecting to build a 50 MPH 60 mile range e-bike for "$1000 preferably, possibly able to budget up to $1300 if need be."

Lots more points to consider. This work could quickly become overwhelming. Need to find a competent editor who can compile the info efficiently and whip it into shape in a format that (as you importantly noted) translates well.
 
99t4 said:
Lots more points to consider. This work could quickly become overwhelming. Need to find a competent editor who can compile the info efficiently and whip it into shape in a format that (as you importantly noted) translates well.

Thanks. I think I'll try updating the first post, by editing it, and as newb questions come up in the forum(s), and can add the questions (if not already addressed) and the responses received from the experts. That way the information will stay in the first post, and easier to copy and paste into a sticky, if the mods feel like it will add some value or save time.

I'll beef up the torque arm part and the unrealistic expectations per your suggestion.

It'll be a work in progress for now. Thanks again for the feedback.
 
E-HP said:
Torque arms: If you choose a direct drive motor, and the kit doesn't include a torque arm, you should purchase one (or two). Don't cheap out on torque arms, they must fit tightly to be of use.
  • Threads:
    • https://endless-sphere.com/forums/viewtopic.php?f=2&t=93562&hilit=torque+arm+photos
      https://endless-sphere.com/forums/viewtopic.php?f=6&t=56621
We'll have to find some TA threads more appropriate to newbs. The first one is certainly interesting but applies mainly to the GMAC motor. Might be too taxing to expect newb to read thru 8pp of interesting development&testing progress that ultimately doesn't give them instant gratification. The second link is a YT video that I cannot access ATM so will not comment yet.

Something like this https://www.electricbike.com/torque-arm/ seems to me better suited for newb. If similar does not exist on ES [EDIT: I have not found it yet] we could just CliffNotes it into this thread, talking about especially the section approx. 1/3 in where it describes the Grin Double Hoseclamp Universal Torque Arm. Could even link to this page https://ebikes.ca/product-info/grin-products/torque-arms.html which gives a good illustrated description on the necessity for a TA, and the reason to avoid the V.1 version and its ubiquitous clones.

I think the goal is to reinforce the requirement for the TA and give them an easy simple high-quality solution that will work for most common cases.
 
Not everybody had the time to answer that noobs questions over and over. I did, back when I was sick in bed, waiting to die in 2010. Now I'm recovered and would rather be out riding. And what I know is getting out of date, fast.

A really good sticky answering the basic newb questions it a great idea. Others have done some great stickies, but more technical and aimed at more advanced builders.
 
As above, excellent idea. Too bad new proponents can't be required to read before asking the same questions repeatedly.
 
Trip Simulator - https://ebikes.ca/tools/trip-simulator.html
Change the Input at the top left of graph to Google Maps and right click your start point and end point then move the route line to your desired route by dragging the line holding the left mouse button down.

Learn links - https://ebikes.ca/learn.html

Spoke Calculator - https://ebikes.ca/tools/spoke-calc.html

Looking for an ebike conversion and not sure where to start?
https://ebikes.ca/getting-started/start-here.html

The Parts of an Ebike System
https://ebikes.ca/getting-started/ebikes-parts-explained.html

Kits Vs Turnkey
https://ebikes.ca/getting-started/kits-vs-turnkey.html
 
Added a lighting section <DOH>. I forgot how often the subject comes up. If anyone knows the current limit of the lighting output on KT controller is, please chime in.
 
My thoughts: Like the sticky threads but would like the side talked removed.
Could have the main sticky thread and facts and links with a companion thread like this one that discusses the thread, suggested updates and links good and bad that link to each other.

There is a lot of information here that is repeated over and over better to search it down and add the links to the sticky.
My hat is off to amberwolf who seems to know or finds these for everyone.

This is great.
 
E-HP said:
Added a lighting section <DOH>. I forgot how often the subject comes up. If anyone knows the current limit of the lighting output on KT controller is, please chime in.

There is a thread with a post from yesterday that says the manufacturer quoted them 70mA. (seventy milliamps). I'll edit in a link if I can find it again.
 
Made a couple of updates since the last post; still a work in progress, but if there are any newbie questions and solutions that you tend to see over and over, suggestions and input appreciated.
 
As a newbie I had an assumption a larger motor and/or contoller would achieve better performance with a 36v battery, but a larger motor must have more voltage to improve and a larger controller has a different LVC(low voltage cut out) which limits the voltage aquired from a smaller battery.
 
"larger" motor (or controller) meaning ? "smaller" battery meaning ?

Normally larger motor would need more phase current to perform better. This is done by the controller, regardless of the battery voltage.

A larger controller normally just means it can supply more power, regardless of battery voltage--it does not require having a higher LVC, just that it can supply more phase current to the motor.

Often higher power systems use higher voltage instead of higher current to acheive that, but they don't have to. (hardware could be chosen or designed around a lower battery voltage and higher battery current to get the same watts).

If you want to see how this works, you can use the ebikes.ca motor simulator.


Also, the LVC doesn't limit the voltage "acquired" from a smaller (lower voltage) battery. It only limits the available capacity from it, as well as the current. The voltage the system sees from the battery is identical regardless of the LVC. All the LVC does is limit or shut off motor power (controller LVC) or shut off battery output (BMS LVC) once the voltage drops (or sags under load) to that limit.
 
Added hyperlinks for controller display manuals. There are several versions of manuals, so if there are better versions that you know of, I can update.
 
I found this awesome link to a chart that lists the wire gauge (AWG) and the (conservative) current rating. I've used this chart to see (approximately) what my existing phase wires can handle and have adjusted my controller as needed. This chart may help others avoid melting wire.

 
Added hyperlinks for controller display manuals. There are several versions of manuals, so if there are better versions that you know of, I can update.
Hello there, I just can't find the link to display manuals, sorry if i'm being dumb, could you tell me where it is?
 
Hello there, I just can't find the link to display manuals, sorry if i'm being dumb, could you tell me where it is?
The displays listed in the display section are hyperlinked, so you just need to click on the display name and the manual should pop up.
 
FWIW, since external links rot as companies change servers, software, etc., or go out of business, I highly recommend attaching the files directly to this thread. (yes, it is a lot of work, especially since I think 20 attachments max per post....but worth it to preserve the info if that's the point of this thread).
 
FWIW, since external links rot as companies change servers, software, etc., or go out of business, I highly recommend attaching the files directly to this thread. (yes, it is a lot of work, especially since I think 20 attachments max per post....but worth it to preserve the info if that's the point of this thread).
Thanks for the suggestion; makes sense. I only added the hyperlinks because the manuals are readily available, so copying and pasting was easy. That section was originally only meant to list which display models mate with which controller manufacturers.

The thread is just a WIP, so while the purpose might eventually lead to a usable FAQ, for now it's basically a place that I can compile information that either is discussed frequently, provided to me (I just added slaphappygamer's wire gauge link today), or is new (to me), for later reference when those subjects come up. It reduces typing for me, so since I've been using my tablet instead of my laptop lately, it's easier to copy and paste or forward a hyperlink, than typing on a virtual keyboard. ;)

BTW, thanks for the info about 20 attachments per post. I tend to just update the main post, but haven't been doing much in the way of attachments, yet.
 
If you are interested in continuing to improve this post then i'd be happy to pin it.

Let me know when you think it's ready :)
 
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