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
ebikes.ca
Learn links Grin ebike learning page
Motor Concepts https://www.maxongroup.com/medias/sys_master/8798985748510.pdf
General:
How far, how fast, etc.:
...
Kits Vs Turnkey - Why DIY?
DIY Newb - Kit builder (all components were purchased as part of a kit, battery with a compatible connector may be purchased separately)
Tools:
Batteries:
Notes on battery safety:
Torque Arms:
DIY Newb - Component builder/upgrader (some or all components were not purchased as part of a kit)
Tools:
Troubleshooting:
Controllers and Controller Resources:
PAS:
ebikes.ca
Motors and Motor Resources (work in progress)
Chinglish to English Translations (work in progress)
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, TommyCat testing guides
07-31-24 - added Cycle Analyst section, and Cycle Analyst 3.15b6 - Settings Summary provided by slaphappygamer
08-05-24 - added framework for Motors section. added link to q factor post related to BBSHD by ebike4healthandfitness
10-15-24 - added link to battery cell database provided by Diggs
01-03-25 - added note on throttle control modes to Controller section
01-06-25 - reordered sections
01-12-25 - added display protocol info provided by amberwolf (link to stancecoke ES post)
02-11-25 - added custom display section
03-13-25 - added Potpourri section to collect interesting solutions and uncategorized links
03-19-35 - started BMS subsection under Batteries (work in progress)
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.
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
Simplified Diagram of a Battery, Controller, and BLDC Motor
The Parts of an Ebike System
Ebike Parts Explained - Getting Started
Here we give a brief summary of the key components that make up an ebike conversion and the role that they play. Some things like motors and batteries are probably familiar to everyone, while motor controllers, PAS sensors, etc. are less familiar but important to know about.
ebikes.ca
Learn links Grin ebike learning page
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. Speed vs. range are a trade off if your budget is fixed.
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.
...
Kits Vs Turnkey - Why DIY?
Conversion Kit SelectionLooking for an ebike conversion and not sure where to start? Things to consider:
DIY Newb - Kit builder (all components were purchased as part of a kit, battery with a compatible connector may be purchased separately)
Ebike kits are usually comprised of a motor and controller plus optional peripheral components, such as a display, pedal assist sensor, and throttle. Some kits may also include a battery as an option, but in most cases, the battery is purchased separately. In the case of the latter, the battery should be purchased, selecting the same type of connector as the controller accepts.
Kits are an easy way to get into DIY ebiking, since all components are compatible and usually "plug n play".
In many or most cases, a kit becomes an introduction to ebiking, and can provide the DIYer a great experience. Over time, many DIYers will "outgrow" their kit as they begin to discover areas where they may want more options or increased performance, range, comfort, etc. In other words, kits are seldom a "one and done" option, but rather a learning experience about the DIYer themselves and what their desires are, after the initial glow has faded.
Some DIYers may know this about themselves well before delving into this new hobby. For those folks, they may want to keep in mind flexibility in kit components that may allow an upgrade path for the future. An example of this would be selecting a kit that has a controller that can operate across a range of voltages (e.g. 36V/48V/60V), that allows the DIYer to initially power their kit at a lower voltage, with the ability to upgrade just the battery rather than battery and controller if they desire more speed or torque in the future.
Tools:
Required: Hand tools for installation;
Optional/recommended (useful for troubleshooting): Digital Multimeter (DMM)
...
...
...
Kits:A complete ebike kit often comes with a bldc controller, display (and buttons), brake cutoffs/levers, PAS sensor and laced hub motor. There may or may not be an option to purchase a battery at additional cost. Some kits may include lights. Mid drive kits often replace the bicycle's bottom bracket, crank arms and front chain ring, and utilize the bicycle's existing drivetrain. The kit will also include/require some peripheral components that are usually included. Battery will be purchased separately.
Important Note: If a display is part of the requirement, then it is important to purchase the controller and display as a set. Purchasing separately is not recommended. See note under the Display section below.
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.
BMS (Battery Management System)
Manages a battery pack, monitoring voltages and currents, at both pack and cell levels, in order to protect the cells, keeping them within their specified ranges. The BMS may also perform balancing functions in order to keep all cells in the pack at the same voltage.
Common Port (single) vs Separate Port (dual) BMS
A common port BMS has a charge port and discharge port electrically connected. If the BMS detects high voltage, it cuts off charging, if it detects low voltage, it cuts off load. The separate port BMS has the load and charge port electrically separate. The BMS It can shut off charging at a specified voltage. I can disconnect load due to low voltage, but not disconnect charging. Common vs Separate port become more relevant when battery packs are combined either in series or in parallel, and how protection of the packs can be maintained. In most situations where packs are combined, common port BMSs can continue to protect the packs independently. Some two pack configurations can still work with one pack having a common port, while the second uses a separate port BMS.
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.
Balancing: Informative article on top vs. bottom balancing
Cell database: Cell Database
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; ideally an interference fit. Note that torque arms included with economy kits are only barely better than nothing, so the cost of a quality torque arm should be included in the project budget, or risk possible catastrophic failure and injury.
- Threads:
torque arm picture thread
Cross-posting these two threads so a search will turn up both: "Found an awesome torque arm" (3 pages) https://endless-sphere.com/forums/viewtopic.php?f=1&t=11570 xxxxxxxxxxxxxxxxxxxx Original thread died. Figured I'd help out and repost what I saved. Here is the album link...
endless-sphere.com
2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
In some sense this is a decades old follow up to our initial torque arm experiments from this thread https://endless-sphere.com/forums/viewtopic.php?p=211356#p211356 The standard for imported ebike hubs back then was M12 or M14 axles that were ground flat to 10mm in order to use the dropout...
endless-sphere.com
C washers - Torque Arms - etc Vid
http://www.youtube.com/watch?v=bUe3EVRIRPM&feature=youtu.be bUe3EVRIRPM
endless-sphere.com
- 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.
Torque Arms - Grin Products - Product Info
For every force there is an equal and opposite force, and for every torque there is an equal and opposite torque. Sadly with import hub motors this opposing torque is often born entirely by bicycle dropouts that are not up to the task, allowing the motor axle to spin out. Grin has pioneered the...
ebikes.ca
- Torque Arms on Hub Motor Bikes
DIY Newb - Component builder/upgrader (some or all components were not purchased as part of a kit)
The DIY component builder chooses various components to support their end goal. The components may not be directly plug n play, but may require testing and troubleshooting, as well as physically modifying things like connectors in order for the components to be connected together. Patience and discipline are required in order to not damage components when they are connected or operated. The reward for the component builder is building an ebike that is specifically tailored to the needs of the particular DIYer, and while sometimes challenging, provides an ebike better matched to DIYer, and almost always worth the additional work.
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
Troubleshooting:
Because a component build will likely not involve a simple assembly of "compatible" parts with matching connectors or conductors, it is important to build troubleshooting skills using a disciplined and methodical approach. The findings of each step eliminate the "wrong" solutions, in order to eventually lead to the correct solution, while not damaging any of the components in the process.
Frequently Newbs attempt to short cut the process by using a guess and see what happens approach, trying different things, connecting wires and connectors randomly, which frequently leads to damaged equipment. Electronics can be very unforgiving.
Displays and Display Resources:
Displays from different brands are not usually compatible. Even 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.
** Some displays have been reported to have selectable communications protocols. ES thread
Common Display to Controller Manufacturer Compatibility (actual compatibility may be dictated by firmware):
- DC MOTO CONTROLLERBYLITHIUMBATTERY/JN SW900***, S700, S800, S830, S866, S886, S890, S900, GD06, OMT-M3, EN06
- Lishui SW900***, C500B-LCD, KD21C, KD51C, KD59E, KD716, KD718
- XLD (XunLiDa Electronics) BrainPower S866, S869, S886, M5, M6T, LH100, 5 wire ZQ-100**
- Kunteng "KT" LCD3, LCD4, LCD5, LCD7, LCD8H, LCD8S, LCD9, LCD10H, LED880, LED900S
- Bafang C961, 500C, 750C, 800S, 860C, DPC-07, DPC-18
- Tongsheng TSDZ2 VLCD5
- (Nanjing,,,,) S810A, S810B1, S810B2, S810B3
- Sabvoton (only a small number of models support displays) 750C, SW900***, TF-M8, 860C, TFT-H6, UKC1
** Several variations of the ZQ-100 display/throttle exist, and are not interchangeable. Some are 5 wire and some are 6 wire. Some of the similar models include, the LH-100, QS-S4, JH-01, NJAX-T, in both 5 and 6 wire versions. The majority of these display throttles combinations are used in electric scooter applications, and less frequently for ebikes. Note the throttle signal output may be the traditional analog voltage or in many cases a digital signal that only a compatible controller can utilize.
*** The SW900 uses many versions firmware making it compatible with specific controller manufacturers or models. In other words, a SW900 with firmware compatible with a Lishui controller, will likely not work with a Sabvoton controller, for example.
Displays and/or Controllers supported by Open Source Firmware (custom/enhanced firmware developed by the user community):
Controllers (additional information provided below, in the controller section) -
Displays -
KT LCD3 used in conjunction with TSDZ2 mid drive*
VLCD5, VLCD6, XH18, LCD3, 860C, 850C, SW102 used in conjunction with TSDZ2 mid drive*
*Torque sensing PAS support
Custom Displays
CT-22 (speedometer, odometer, voltage, and status display)
Grin Cycle Analyst, computer and dashboard*:
*Torque sensing PAS support
Controllers and Controller Resources:
Kunteng- Imitation Torque Controller--Suzhou Kunteng Electronics Co.,Ltd--Suzhou Kunteng Electronics Co.,Ltd
Votol - Qima Technology
Nanjing Fardriver - far-driver
Grin - Controllers - Ebike Parts - Shop
XLD (XunLiDa Electronics) Brainpower -
JN, JH (often labeled "DC MOTO CONTROLLER BY LITHIUM BATTERY" or "Brushless DC Motor Controller") -
Bafang - OEM Area
BBS## programing and resources - Bafang Programming - Learn how to improve your Bafang mid-drive ebike - Edrivenet
Sabvoton/MQCON - MQCON-e bike controller supplier
Note: Throttle Control Modes - The controller's MCU determines how a throttle input signal translates to output to the motor. It may do so by taking the throttle input voltage and translating that to a target RPM (speed), or to power, or current (torque). The mode may dramatically change how the motor responds to a throttle input.
Many budget controllers use an RPM based throttle control. Under this type of control, the controller will output full power until it achieves the target RPM and then drops the power to maintain that RPM/speed. This can make both the PAS, and especially throttle, difficult to control, with a feeling of the motor surging or pulsing, but may be preferred under certain applications.
Most programable controllers, as well as the Cycle Analyst, have the ability to change between throttle control modes to the user's preference. Note that since the Cycle Analyst operates under a closed loop (monitors voltage, current, and speed), it can implement all three control modes even when the controller's native mode is speed based.
eBike Lighting?
- Very few aftermarket controller can fully support ebike lighting
- Plan on challenges if upgrading a controller on a factory ebike with integrated lighting
List of controllers with lighting functions (work in progress):
- 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
PAS:
Pedal assist sensors fall into two general categories, cadence based PAS and torque sensing PAS. Note that in order to implement PAS, other components, such as the controller must also support the PAS function and interface with the pedal assist sensing unit.
Cadence: Cadence PAS can operate in a couple modes, depending on how is supported by the controller. Simple cadence PAS can provide assist when the pedals are turning forward, regardless of how fast the pedaling is. To control the amount of assist, the controller may have control buttons to select a fixed level of assist, by PAS level. Cadence PAS may also operate in a manner the changes assist based on how fast the pedaling is, again, based on what is supported by the controller.
Torque: Torque sensing PAS operates based on pedaling effort. The amount of pressure applied to the pedals will determine the amount of assist provided. Pedaling harder increases assist. The controller used for torque sensing PAS may also have PAS levels, similar to cadence PAS, that adjust the overall assist level, but the amount of assist at any given level is still determined by pedal pressure. Some torque sensing PAS units also support cadence sensing to further adjust assistance based on the cadence.
PAS controllers:
Not all controller support PAS, but ones that do usually support cadence PAS, which is common with budget controllers. PAS support will usually be described in the controller's documentation or on its label.
Torque sensing PAS controllers:
Controllers supporting torque sensing PAS are less common, and usually more expensive. Below is a non-exhaustive list of controllers that natively support torque sensing PAS*:
- Grin Phaserunner, Baserunner controllers
- Grin cycle analyst computer/display (used with any controller with a throttle input)
- Some models of KT controllers, however these may not be currently available. B. B. Torque Sensor System (link provided by member stancecoke)
- Some Lishui controllers
- Some controllers that normally don't support PAS, or only support cadence, can support torque sensing PAS when the controller or display is flashed with open source firmware. Some KT controllers and Lishui controller fit under this category.
* Cadence and/or torque sensing, can also be supported by some peripheral components, such as the Grin Cycle Analyst (see above), that will process the PAS signal prior to passing it through to a non-PAS supporting controller.
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
Some throttle units have other functions like controller on/off or voltage displays, so those throttles will have 2 or 3 additional conductors, in addition to the three used for throttle.
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): to be added
Display wiring, single wire: to be added
...
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.
Anti-theft:
Wire Gauge Current Limits:
American Wire Gauge Chart and AWG Electrical Current Load Limits table with ampacities, wire sizes, skin depth frequencies and wire breaking strength
AWG Wire size chart and ampacity table for design engineers including skin depth frequencies and tensile strength data; electrical cable size
www.powerstream.com
Connector References:
Connectors - Learn
There are lots and lots of connector types used in the ebike industry, so many that it would be a very tall order to try and list them all. In our business, we focus just on aftermarket conversion kits and have tried to keep the connector styles down to a well chosen minimal set. This page...
ebikes.ca
DIY Garage; Connectors for Halls, Throttle, and Motor
Experienced builders have preferences for every part of their hot rod ebike, but…if you are new and you just want some advice on how to get started with components that work well enough, and …
www.electricbike.com
Motors and Motor Resources (work in progress)
Hub motors
Direct Drive
xxxx
Geared Drive
xxxx
Locked geared drive
xxxx
Mid drive motors (DIY)
Bafang
BBS##
Tong Sheng
TSDZ2
CYC
X1 Pro
X1 Stealth
Photon
Custom/kit/misc
Stokemonkey
Testing, Tuning, and Troubleshooting Resources:
Testing guides by Tommycat -
...
Wheel Building:Spoke Calculator - Online Spoke Calculator for Hubmotors and Ebikes
Buy & Build?DIY factory bike modder (work in progress)
Potpourri (A collection of interesting solves and links)Chinglish to English Translations (work in progress)
- 3 Position Switch/3 Speed Switch/3 Grade Switch/3 Grade Speed/Gear HML : Controls 3 power or speed levels of the controller; the middle position is default
- 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).
- Lack Voltage : Low voltage cutoff
- Learning/Learning Line/Self-study/Self-learning/Automatic Detection/Automatic Identification/Auto Learn/Intelligent Recognition/ : Motor Hall and Phase detection. Jumper to enable automatic detection of motor hall/phase combination
- Low Brake/Low Voltage Brake/Low Power Brake/Brake Signal Line/ : Brake Cutoff
- Throttle/Speed Governor/Accelerator/Turn Handle/Speed Steering 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, TommyCat testing guides
07-31-24 - added Cycle Analyst section, and Cycle Analyst 3.15b6 - Settings Summary provided by slaphappygamer
08-05-24 - added framework for Motors section. added link to q factor post related to BBSHD by ebike4healthandfitness
10-15-24 - added link to battery cell database provided by Diggs
01-03-25 - added note on throttle control modes to Controller section
01-06-25 - reordered sections
01-12-25 - added display protocol info provided by amberwolf (link to stancecoke ES post)
02-11-25 - added custom display section
03-13-25 - added Potpourri section to collect interesting solutions and uncategorized links
03-19-35 - started BMS subsection under Batteries (work in progress)
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:
