Protocolos de comunicação em sistemas eléctricos de bicicletas eléctricas

Electric bicycles (e-bikes), including cargo e-bikes, rely on an intricate electrical system to link the battery, motor, controller, sensors, and user interface. This system’s communication protocols serve as the “language” that allows all these components to coordinate seamlessly . In this popular science overview, we will explain what these communication protocols are and how they function within e-bike electrical systems. We’ll cover the types of protocols used, how they differ, where each is applied, their pros and cons, cost considerations, compliance with safety standards in the EU and US, and limitations. The goal is to provide a clear, authoritative guide for our customer and audience , balancing technical depth with practical understanding.

E-Bike Key Components – The “Nervous System”

E-bikes can be thought of as having a central nervous system of wires and data links that connect all critical components . Just as nerves carry signals in a body, the wiring harness carries both power and data signals across the bike . Key components in a typical e-bike electrical system include:

• Battery Pack: The DC power source (commonly 36–48 V) that supplies energy to the system . It connects to the controller via thick power cables (with fuses or breakers for safety) to deliver the main current. Some advanced batteries also have a data link (via communication lines) to share status or control signals with the controller.
• Motor and Controller: The motor (hub motor in a wheel or a mid-drive at the crank) receives power from the motor controller, which is the “brain” regulating motor output based on rider inputs and sensor feedback . The controller is an electronic unit with a microprocessor that takes in signals (throttle, pedal sensor, brakes, etc.) and manages power to the motor. Motors typically have phase wires (heavy cables carrying power) and sensor wires (thin cables from Hall effect sensors providing rotor position feedback) going to the controller .
• Human Interface (Throttle, Pedal Sensor, Display): The rider communicates with the e-bike through devices like the throttle (often a handlebar grip with a Hall-effect sensor that outputs a variable voltage signal to request speed) , and the pedal assist sensor (PAS) which detects pedaling motion via magnets and sensors . The display unit on the handlebars shows speed, battery level, assist level, etc., and often includes buttons for the rider to adjust settings. The display and controller exchange data through a multi-wire cable including power and communication lines .
• Safety Cutoffs (Brake Levers): E-bike brake levers usually have cut-off switches that send a signal to the controller to immediately cut motor power when braking . Typically, a simple two-wire circuit is used for this, acting as an on/off signal to the controller .
• Lighting and Accessories: Many e-bikes also integrate front/rear lights, horn, USB chargers, etc. These may be controlled by the main controller or operate on separate circuits, but in high-end systems they can be addressed via the communication bus as well.

For a detailed guide to accessories for ebikes and cargo bikes, you can read this article for a more comprehensive answer , or maybe check our Cargo Bike 101 page.

Figure 2: Block diagram of a typical electric bicycle control and battery management system. The central controller interfaces with key inputs—throttle, pedal sensors, brake levers—and manages outputs such as motor drive signals via gate drivers, relay drivers, and GPIO connections. Optional modules like LCD displays, battery chargers, fuel gauges, and backlights extend system functionality. Communication between components supports real-time coordination of motor power, lighting, safety cutoffs, and battery status monitoring.

What Are E-Bike Communication Protocols?

In the context of e-bikes, communication protocols refer to the method and format by which electronic components exchange data. Early or basic e-bikes often didn’t have a complex digital network – many signals were analog or simple on/off circuits. For example, a throttle sends an analog voltage to indicate how much power the rider wants, and a brake switch simply opens or closes a circuit to cut power . However, as e-bikes have become more sophisticated – with smart displays, advanced sensors, and even GPS or smartphone integration – a need arose for more robust digital communication.

Today, two primary digital communication protocols dominate e-bike systems:

• UART (Universal Asynchronous Receiver–Transmitter): A serial communication method that creates a direct one-to-one data link between two devices (typically the controller and display).
• CAN Bus (Controller Area Network): A network protocol that allows multiple devices (controller, display, battery BMS, sensors, etc.) to all communicate over the same shared bus wires.

In addition to UART and CAN Bus, two other communication protocols are occasionally used in e-bike systems:

• SIF (Serial Interface Format): This is a proprietary or simplified protocol commonly found in certain branded systems (e.g. Shimano STEPS or older display units). It’s typically used for basic data exchange between the controller and display or remote buttons. Because SIF lacks open standardization and flexibility, it’s mostly limited to specific brands or legacy models.
• RS-485 (Recommended Standard 485): RS-485 is an industrial-grade serial communication protocol known for its long-distance reliability and noise resistance. Though not as common as UART or CAN in consumer e-bikes, it appears in some high-end or commercial fleet systems, especially where robustness and extended wiring are required—like shared bikes, rental fleets, or heavy-duty e-bikes.

These protocols are essentially the “languages” of the e-bike’s electronics. If all components speak the same language, information flows correctly; if not, devices won’t understand each other . That’s why matching the protocol is critical when pairing a display with a controller, for instance. Even if the plug fits, an incompatibility in protocol means the parts won’t work together .

Market Usage Overview (2024–2025 Estimated Trends)

While there’s no universally published breakdown of protocol usage in the e-bike market, based on industry insights and major system vendors (e.g. Bosch, Bafang, Shimano, Mahle, etc.), the following is a reasonable estimated distribution as of 2025:

Nota: These figures are generalized across global markets (EU, CN, NA) and are based on OEM trends, public documentation, teardown data, and component supplier insights.

Define E-Bike Communication Protocols in easier way ：

In simple terms, communication protocols in e-bikes are like languages or rules that let different electronic parts talk to each other. If the components don’t speak the same language, they can’t understand each other—even if the plug physically fits.

📞 Analogy: One-on-One Call vs. Group Chat

Let’s imagine two ways of communication in everyday life to understand e-bike protocols:

UART: Like a One-on-One Phone Call

• UART (Universal Asynchronous Receiver–Transmitter) is like calling one friend on the phone.
• Only two devices can talk at a time—like your display and your controller.
• If you want to talk to another device, you need another wire (or another phone call).
• It’s simple, but not scalable when you have many devices.
• Common in basic e-bike systems with limited features.

AN Bus: Like a Group Chat

• CAN Bus (Controller Area Network) is like a group chat on WhatsApp or WeChat.
• All devices (controller, battery, display, sensor, lights) are in the same chat room.
• Each message is tagged with a sender ID, and each device reads only the messages meant for it.
• It’s much more efficient and ideal when there are lots of components that need to work together.
• Used in smart, advanced e-bike systems, often with GPS, Bluetooth, and app integration.

The Role of Communication Protocols

Communication protocols in e-bikes serve several important purposes:

• Data Sharing: They allow the controller to send real-time data to the display (speed, battery state of charge, error codes) and receive commands back (e.g., change assist level, lights on/off) . Without a proper protocol, you might not get a reliable speed reading or could be unable to adjust settings.
• Coordination of Components: In advanced systems, multiple microcontrollers need to coordinate. For example, a smart battery with its own Battery Management System (BMS) might communicate with the motor controller to prevent over-current or to display precise battery percentage. A CAN bus or similar network allows the battery, motor controller, display, and even sensors to all share information in a multi-node network.
• Safety and Reliability: A well-designed protocol ensures that if there’s a fault or a loss of signal (say a cable is damaged), the system can detect it and take safe action (like cutting motor power). Robust protocols like CAN include error checking and message prioritization to handle this . Simpler analog signals lack such error-handling – if a throttle wire comes loose, the controller might misinterpret noise as a throttle signal unless safety provisions are in place.
• Expandability: For feature-rich e-bikes (GPS trackers, anti-theft immobilizers, multiple assist sensors, etc.), a communication network makes it easier to add or remove devices. Instead of each new device needing a dedicated wiring link to the controller, a device can join the common bus and share data with all others. This scalability is a key reason modern high-end e-bikes are moving toward CAN bus .

In summary, the communication protocol is a backbone of the e-bike’s electrical system, ensuring all electronic parts work in concert. In another post, we’ll dive into the two main protocol types (UART and CAN), examining how each works and their respective use cases in e-bikes and cargo e-bikes. check if you are interested:

1. “Understanding UART in E-Bikes: How Simple Serial Communication Powers Your Ride”
   • A beginner-friendly guide to how UART enables basic data exchange between e-bike components like displays and controllers.
2. “What Is CAN Bus in E-Bikes? A Smarter Way to Connect Batteries, Sensors, and More”
   • Learn how modern e-bikes use CAN Bus to support multi-device communication, advanced displays, and system diagnostics.

Application Scenarios: Which Communication Protocol for Which E-Bike?

It’s useful to understand how UART and CAN are chosen in practice for different e-bike designs. We’ll consider two broad categories: consumer e-bikes (including typical commuter or leisure bikes) e cargo/fleet e-bikes (often used for business deliveries or by rental fleets), noting that these often have different priorities.

• Standard Consumer E-Bikes (City, Mountain, Road e-bikes): These are the bikes many individuals buy for personal use. They range from entry-level to very high-end. On the lower end (cost-sensitive models), UART communication is extremely common. For example, a simple 36V commuter e-bike with a cadence pedal sensor and basic LED display likely uses a UART (or even analog signals) between the controller and whatever minimal display it has. The focus here is cost-effectiveness and basic functionality. Many such bikes use widely available controllers and displays that adhere to a de facto UART protocol, which means bike brands can source components from different OEMs. This is attractive to B2B buyers who want the flexibility to use, say, a nicer display from Vendor A with a controller from Vendor B – as long as both speak UART in the same format, it can work (though one must verify compatibility on pinouts and firmware) . On the higher-end consumer bikes, especially those made by big brands, there’s a trend toward CAN bus. High-performance e-MTBs or e-road bikes with torque sensors and fancy displays might use CAN to integrate everything smoothly. However, some brands still use UART or other proprietary serial links even in high-end bikes; it varies by manufacturer and their design philosophy.

• Cargo E-Bikes and Commercial Fleets: Cargo e-bikes are designed to carry heavy loads or passengers and are often used by businesses (delivery services, postal bikes, etc.). These bikes tend to prioritize robustness, safety, and fleet management capabilities over cost of electronics. It’s in this segment that CAN bus has really gained ground. For instance, cargo bikes may have baterias duplas to extend range – managing two batteries requires communication to balance discharge or at least to report status of each. CAN makes it easier for one controller to communicate with two BMS units (one in each battery) on the same bus. Cargo bikes might also have additional accessories: brake lights, turn signals, even electronic locks – coordinating these via a central bus simplifies wiring and control. Moreover, because cargo e-bikes often operate in fleets, companies like to have telematics on them: GPS trackers that can report the bike’s location, usage, and any faults. With a CAN-enabled system, a telematics module can simply eavesdrop on the CAN messages for speed, battery status, etc., and upload that info. In fact, one case study with a European delivery fleet demonstrated that tapping into the CAN bus allowed remote monitoring of maintenance data (like mileage), remote motor disable for anti-theft, and over-the-air updates of bike firmware – features extremely useful for fleet management. This would be cumbersome to implement on a UART-based bike.
• Mix-and-Match vs. Integrated Systems: If an e-bike brand wants the freedom to mix components or allow aftermarket upgrades, they tend to stick with UART-based systems. We saw that UART systems allow swapping displays or tweaking motor settings readily. A smaller e-bike company might prefer this route to avoid being locked to one supplier – they can change motor/controller suppliers without changing the whole ecosystem, as long as the protocol remains UART and they can adapt the firmware. On the other hand, brands focused on system optimization and compliance often choose CAN. For example, Bosch-driven e-bikes use a CAN-like bus (Bosch has a proprietary CAN-based protocol) connecting their motor, display, and battery. This ensures no third-party parts can interfere; everything is finely tuned together. The upside is excellent reliability and safety – the system will throw an error if anything is out of spec. The downside is as a B2B buyer (like a bike OEM choosing Bosch), you are committing to buying the motor, controller, battery, display todos from Bosch as a package.
• Cargo Bikes – Specific Considerations: Cargo bikes, especially in the EU, often face stricter scrutiny because they might carry heavier loads or even passengers. In Germany, for example, there’s a standard (DIN 79010) specifically for cargo bike safety (mostly mechanical aspects like frame strength and braking) . While that standard doesn’t dictate communication protocols, the safety-first mindset in cargo bikes encourages using a protocol that can ensure, for instance, that if something goes wrong (overheating motor or low battery), the system can communicate it and take action. CAN’s robustness and error-handling help meet these safety goals. Additionally, cargo e-bikes often operate in urban environments (delivery in cities) where there’s a lot of radio/electrical noise and the stakes are high if a communication error occurs at the wrong time. The noise immunity of CAN is a big plus here, preventing miscommunication that could lead to erratic behavior.

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Safety Standards and Compliance of electric system (EU/US)

Regardless of the communication protocol used, e-bike electrical systems must adhere to safety standards to ensure they operate safely and legally, especially in key markets like Europe and the United States. The communication protocol can indirectly affect a bike’s compliance – for example, a protocol that allows unrestricted user modifications might pose a compliance risk, whereas one that is locked down can help ensure the bike stays within legal limits. Let’s break down the relevant standards and how they relate:

How Communication protocols affect ebike’s compliance in European Union

European Union (EU) – EN 15194: In the EU, most e-bikes (pedal-assist bicycles with motor output <= 250W and assistance cut-off at 25 km/h) are classified as EPACs (Electronically Power-Assisted Cycles). The standard EN 15194 applies to EPACs and defines requirements and test methods for safety and performance . This includes mechanical safety (brakes, frame, etc.) and electrical safety (wiring, EMC, etc.), as well as ensuring the bike meets the speed and power limits.

• For communication protocols, one relevant aspect is electromagnetic compatibility (EMC): the system shouldn’t emit excessive interference or be unduly affected by interference. A well-designed CAN or UART communication line should pass EMC tests (EN 15194 refers to EN 55014 or similar for EMC). The noise-resistant nature of CAN can be an advantage in meeting these EMC requirements since it inherently deals with noise better, but UART systems can also comply if properly shielded.
• Speed and power tampering: EN 15194 requires that the assist cuts off at 25 km/h and that the user can’t easily adjust this limit above the legal value. If a bike uses UART and the manufacturer leaves programming pads accessible, a user could potentially derestrict it – this might raise compliance issues. Some manufacturers therefore use locked CAN systems specifically to prevent users from changing the speed limit. For instance, Bafang’s CAN-based motors have the speed limit fixed and not changeable via display , helping ensure compliance with regulations out of the box. In contrast, on many UART systems, a savvy user could enter settings mode on the display and tweak the wheel size or limit, or use a programming cable, which might break the letter of the law if they make the bike exceed 25 km/h assist.
• Electrical safety: EN 15194 (latest revisions) covers basic electrical safety but interestingly does not fully cover battery safety – it assumes the battery pack itself is to comply with other standards. It focuses more on the integration, wiring, and basic protection (like no exposed live parts, etc.) . A communication protocol doesn’t directly impact this, but indirectly, a protocol like CAN that lets the BMS talk to the controller can enhance safety – e.g., the BMS can send a “stop discharge” command if the battery is overheating. While not mandated by EN 15194, this kind of feature helps a bike meet general safety expectations (avoiding thermal runaway events).

Additionally, European cargo e-bikes (especially those that carry goods/passengers) might have to meet the Machinery Directive if they don’t strictly fall under bicycle rules (some heavy cargo cycles do). This again emphasizes robust fail-safes. Using a solid communication protocol with fail-safe behavior (like CAN shutting down on fault) can assist compliance here.

More info about EU standard of e-bike

How Communication protocols affect ebike’s compliance in the United States

United States – UL 2849 and others: In the US, e-bike manufacturing is a bit less regulated at the federal level for performance (there’s a consumer product definition of a low-speed e-bike as 750W max and 20 mph on throttle/28 mph on pedal assist, but no mandatory construction standards federally). However, safety certification is becoming crucial, especially due to fire concerns from batteries.

• UL 2849 is the premier safety standard for e-bikes’ electrical systems in North America. It covers the entire electrical drive system of an e-bike – including the battery, the motor, the charger, and all interconnections . UL 2849 testing looks at things like whether the wiring can handle the currents, whether the system is protected against short-circuits, and importantly, it also incorporates UL 2271 for batteries (which is a battery-specific safety standard). Communication-wise, UL 2849 doesn’t prescribe a protocol, but it will check that, for example, if communication is lost or a fault is detected, the system fails safely (no thermal events, no runaway motor). A CAN-based system might have a slight edge in proving out redundancy (e.g., if the throttle message is lost, CAN can detect that and time out appropriately). But even UART systems can be designed to meet UL 2849 (they just need thorough fault handling in the controller firmware).
• Fire and Electrical Shock Prevention: Standards like UL 2849 focus on preventing electrical fires and shock. For instance, if an e-bike has a charger connected, the communication between battery and charger (if any) should not lead to overcharge. Notably, the EnergyBus standard we mentioned, which is CAN-based, was partly motivated by safety – ensuring any charger can safely charge any battery by communicating over CANopen and only enabling power when proper handshaking is done . EnergyBus uses a specific connector that includes CAN data lines so that a charger and battery establish communication first, then allow charging current, to avoid sparks or mismatched voltages . This concept aligns well with UL safety logic. If a brand is using EnergyBus, it likely helps in passing safety certifications because it inherently manages safe interactions between components.
• Regulatory compliance (speed/power): In the US, the class system (Class 1, 2, 3 e-bikes) is largely honor-system and not as strictly enforced as EU’s limits, but for liability reasons, manufacturers typically ensure an e-bike sold as Class 2 cannot easily be altered to exceed 20 mph on throttle, for instance. Here again, using a closed CAN protocol can help – users can’t just plug in a cable and derestrict the bike. It’s notable that many e-bike companies now advertise UL-certified batteries or systems to assure customers of safety. For example, HOVSCO (as seen in their knowledge base) emphasizes that their bikes meet UL 2849 for electrical safety and EN 15194 for overall safety compliance . This means their wiring, connectors, and communications must all function without causing hazards.

International and Other Standards: Besides EN 15194 and UL 2849, there are other relevant standards – e.g., ISO 4210 (bicycle safety standard) with a part that covers e-bike requirements, and the German DIN 79010 for cargo bikes (which we noted, covers things like frame strength under cargo loads and braking performance) . These don’t directly dictate the electronics, but a cargo bike standard might implicitly require that, say, the assistance doesn’t malfunction under heavy load. A robust communication ensures that even if the bike is straining (and perhaps electrical noise is up or battery is sagging), the signals between battery, controller, and sensors remain reliable.

Resumindo, compliance and safety drive some design decisions between UART vs CAN. A manufacturer aiming for maximum safety might lean towards CAN for its error-checking and control, or implement extra safeguards on UART systems. Both protocols can be part of a safe design, but how they’re used is key. The closed nature of CAN systems can enforce compliance (e.g., speed limits not adjustable by users, as required by law) , whereas UART systems offer more user freedom, which is a double-edged sword. Manufacturers must ensure even UART-based bikes have things like a physical or software limiter that can’t be easily hacked, to stay within legal limits.

Finally, regardless of protocol, using quality connectors and wiring is part of compliance. In EU, the bike must endure vibration without wires coming loose, and in wet conditions without shorting. Connectors like Higo/Julet (waterproof connectors widely used in e-bikes) are popular not just for convenience but also because they help meet IP ratings and reliability requirements. A CAN bus typically will use such connectors (e.g., a single Higo 4 or 5-pin might carry the CAN data and power for a display). The choice of protocol doesn’t change the need for good strain relief, insulation, and locking connectors to prevent disconnects (which could be dangerous if, say, your brake cut-off signal failed to reach the controller because a cable shook loose).

To conclude this section, both Europe and the US have strong focus on e-bike safety now. Compliance with standards like EN 15194 and UL 2849 is increasingly non-negotiable for reputable brands . The communication protocol is one piece of the puzzle – a means to ensure the electrical system is coordinated and failsafe. CAN bus’s reliability can aid in meeting these standards by providing robust communication, while UART systems require careful design to be just as safe. Manufacturers will often choose the protocol that best aligns with the compliance strategy: UART for simpler designs where the risk can be managed easily, or CAN for complex systems where its safety features shine.

Costs and Market Considerations when choosing the communication protocols

When deciding between communication protocols (or generally designing an e-bike’s electrical system), cost is an important factor – not just monetary cost, but also the “cost” in terms of flexibility and supplier relationships. Here’s how the costs compare and what B2B buyers or engineers consider:

• Hardware Cost: As noted earlier, a UART-based system typically uses simpler hardware. The controller and display just need UART capability, which virtually all microcontrollers have built-in. The wiring might be a tad simpler (fewer termination considerations, etc.). A CAN-based system requires a bit more: a CAN transceiver chip for each device, and possibly a more powerful MCU (though these days even fairly cheap MCUs have CAN built in). The actual BOM (Bill of Materials) difference might be on the order of just a few dollars per bike in high volume , but in a competitive market, that still matters. For a large bike fleet order, those dollars multiply out. That said, the cost of CAN hardware has come down significantly, and the trade-off might be easily justified by the added functionality CAN provides.
• Development and Integration Cost: For an e-bike startup or a small company, developing a CAN-based system from scratch could be costly if they don’t have in-house expertise. It might involve hiring embedded systems engineers familiar with CAN, investing in tools, and spending time to develop custom firmware. Alternatively, if they buy a ready-made system (like Bosch or Shimano drive units, which are CAN-based), the development cost on their side is lower, but the unit cost is higher (Bosch systems are premium priced, partly because you’re getting a fully integrated solution and the brand name). A UART system can often be put together using off-the-shelf components with known compatibility – for example, many companies use open-source or standard protocols where a lot of the engineering is already done, and the risk is lower. For a B2B buyer (say a company that wants a bunch of e-bikes under their brand), going UART might mean they can source cheaper generic parts, whereas going CAN often means aligning with a particular supplier’s ecosystem (which might charge licensing or higher prices).
• After-Sales and Maintenance Costs: This is sometimes overlooked. A fleet operator (like a bike share or a delivery company) might find that CAN bus bikes save money in maintenance. Why? Because they can diagnose issues remotely or more quickly. A CAN-connected system can report error codes in detail (for example, “battery #2 temperature sensor fault” as a specific code). Technicians can plug in diagnostic tools to the CAN bus to pinpoint issues. This can reduce labor time. Also, as seen in the IoT Venture case, things like remote firmware updates are possible , which can save the cost of physically recalling bikes for certain fixes. On the other hand, initial maintenance of a UART bike might be simpler (fewer things to go wrong in the comms, perhaps) but if something is wrong, you might have to do trial and error part swaps since the system can’t tell you exactly what’s wrong beyond maybe flashing an LED. For an individual consumer, a UART bike might be cheaper to repair because they can use off-the-shelf parts and community knowledge to fix it, whereas a CAN bike might force them to go to authorized service (potentially pricier). So there’s a cost trade-off between user-serviceability (UART wins) and advanced diagnostic support (CAN wins, which could lower professional service costs).
• Licensing and Proprietary Costs: Using a proprietary CAN protocol could involve licensing fees or restrictions. If a bike brand develops their own CAN protocol, that’s fine, but if they use something like CANopen or EnergyBus, they might need to adhere to standards and possibly join associations (e.g., EnergyBus e.V.). Those costs are generally small, but worth noting. Proprietary systems like Bosch effectively mean the bike OEM buys the drive units as a package; Bosch sets the price. With UART systems, there’s often more competition among part suppliers, which can drive prices down.
• Customer Perception and Value: From a marketing perspective, a brand might justify a higher price for a bike that has “automotive-grade CAN bus electronics” as it sounds advanced and reliable (even if the customer doesn’t directly see the difference). There’s value in the premium feel and performance that CAN systems often come with (they’re usually on bikes that also have high-quality motors, etc.). So, brands targeting the higher-end market or commercial clients can leverage CAN as part of a premium offering. Conversely, for entry-level e-bikes, customers mostly care that it works and is affordable – they won’t pay extra just because the bike’s display uses CAN instead of UART. So, the protocol choice should align with the bike’s market segment.
• Future-proofing: A cost that engineers consider is the opportunity cost of not being future-proof. If you invest in a UART-based platform now but next year you want to add more features (say a second battery or a new sensor type), you might find the old platform limiting, forcing a redesign. Some companies decide it’s more cost-effective in the long run to go with CAN from the start, even if not fully utilized, to leave headroom for new features and accessories. This can save redevelopment costs down the road. It’s a strategic decision: pay a bit more upfront vs. potentially a lot more later to upgrade.

In terms of actual price figures: it’s hard to pin down, but an industry insider might say, for example, a basic UART e-bike controller + display set could be, say, $50-$100 in bulk, whereas an equivalent CAN-based set from a big brand could be a few hundred dollars (because it’s more sophisticated). However, that difference often also includes better motor performance, warranty, etc., not just the communication difference. The incremental cost purely for protocol (e.g., adding a CAN chip) is small, but the ecosystem cost (tying into an expensive system vs a cheap generic one) can be large.

To put it plainly for a B2B e-bike buyer:

• If your priority is lowest unit cost and you want flexibility to source from multiple suppliers, a UART-based open system is attractive. You can shop around for displays and controllers that match, possibly even negotiate with multiple factories.
• If your priority is performance, reliability, and a turn-key system (and you’re willing to pay for it), a CAN-based system from a reputable supplier might save you headaches and add value to your product (at a higher cost, which hopefully you recoup by pricing your bikes higher or by volume efficiencies).

Limitations and Future Trends

Even as we extol the virtues of UART and CAN, it’s worth noting the limitations of the current state of e-bike communications and where things might be heading:

• Lack of Industry-Wide Standardization: Unlike the automotive world where almost every car uses CAN bus and standardized diagnostics (OBD-II), the e-bike industry is still fragmented. There is no single universal protocol that all e-bikes use. UART implementations vary (each manufacturer may have different data formats over UART), and CAN implementations are often proprietary. This is a limitation for consumers and bike assemblers – it’s not “plug and play” between different brands. You can’t take a random display and expect it to work with a random controller unless they explicitly use the same protocol and firmware. EnergyBus is a promising effort to standardize (with CANopen CiA-454 defining messages for e-bike components) , but it’s not yet pervasive. If EnergyBus or similar standards gain traction, we might see truly interoperable components – for example, a battery from Manufacturer X could be used with a motor system from Manufacturer Y, with the CANopen-based protocol ensuring they understand each other. This would benefit B2B buyers (more supplier options) and consumers (more upgrade/repair options). However, industry players also have business motivations to maintain proprietary systems (to lock in customers). The tension between standardization vs. proprietary control will shape the future of e-bike protocols.
• Bandwidth and Data Needs: Currently, e-bike communications are relatively low-data. But future e-bikes might stream more information – imagine collecting high-frequency torque sensor data, or high-resolution power metrics for training purposes, or even video from cameras for safety. CAN at classic speeds might become a bottleneck if a lot of data is to be sent. The automotive industry has CAN-FD (an extended version of CAN with larger data frames and higher throughput) and other protocols like Ethernet for high-bandwidth needs. For e-bikes, CAN-FD could eventually appear if needed, or BLE/Wi-Fi for offloading data logs. Wireless communication might also complement wired protocols: already many e-bikes use Bluetooth Low Energy to connect the bike to a smartphone app. That’s outside the scope of the internal electrical system, but worth noting as a parallel channel. Perhaps in the future, some simpler e-bikes might even forgo a wired display and use a wireless module to a phone – though critical control (like throttle or brake signals) would likely remain wired for reliability. In cargo fleets, we might see more integration of V2X (vehicle-to-everything) communication – e-bikes talking to logistics systems or traffic infrastructure, which again would be layered on top of the core CAN bus system.
• Security Concerns: As e-bikes get connected and use more complex communication, cybersecurity becomes a concern. A UART system with no external connectivity is practically immune to hacking (someone would have to physically tap into the wires). But a CAN bus that interfaces with a Bluetooth module or a GSM module (for fleet tracking) introduces potential vulnerabilities. Manufacturers will need to ensure their protocols (especially wireless interfaces to the bus) are secure to prevent malicious control (imagine an IoT hack that could disable a fleet of delivery bikes remotely – a far-fetched but theoretically possible scenario if not secured). Proprietary protocols by nature are somewhat secure through obscurity, but as CAN becomes common knowledge in e-bikes, bad actors could attempt to inject CAN messages via an exposed port. Thus, we may see more encryption or authentication in e-bike communications in the future.
• User Experience: Ultimately, whichever protocol is used, it should serve a good user experience. Riders care about things like smooth power delivery, accurate information on the display, and safety features working when needed. A limitation in early CAN-based systems was that they were sometimes too locked down – users felt frustrated they couldn’t even change simple preferences. As systems mature, manufacturers might find ways to give users flexibility (via authorized apps or settings) without compromising the control. For example, maybe an app could allow limited tuning (within safe bounds) even on a CAN system, or allow third-party accessories that are certified to communicate on the bus (perhaps using EnergyBus standard messages). We can expect a bit more openness as protocols standardize, ironically even in a CAN world.

In closing, the electrical communication system of e-bikes – whether UART or CAN – is crucial to the bike’s performance, safety, and modularity. Engineers designing e-bikes must balance the simplicity of UART against the sophistication of CAN. B2B buyers must consider how the choice affects cost, supply chain, and the value proposition of their product. The industry appears to be trending towards CAN bus as e-bikes evolve into more connected and capable machines , but UART-based systems will likely remain in parallel for simpler, lower-cost models for some time (they are, after all, “good enough” for a huge segment of riders).

By understanding these communication protocols – essentially the electrical language of e-bikes – one gains a much deeper appreciation for how an e-bike works internally. From the twist of your throttle or the pressure on your pedal, to the surge of the motor and the numbers on your display, it’s all enabled by bits and bytes zipping along wires, ensuring that battery, motor, and rider are in sync. And whether it’s a sleek city e-bike or a heavy-duty cargo hauler, that harmony is what makes the ride feel effortless and safe. In the end, the goal of any protocol is to make the technology fade into the background so that riders can simply enjoy the journey – but now, hopefully, with a bit of insight into the impressive electronic coordination happening beneath their feet.

Fontes:

1. Qiolor Ebike Guide – “How to Choose a Compatible Display for Your Ebike Controller” (2025) – discussing UART vs CANBUS languages and importance of matching protocols.
2. Velco.tech – “CAN vs UART: differences between communication modes” (2024) – explaining UART’s simplicity vs CAN’s network capabilities and listing their advantages/limitations .
3. Biktrix Help Center – “What are the CANBUS and UART protocols?” – user-centric view on how CAN locks settings (speed limit fixed) vs UART allows modifications , plus a comparison of display interchangeability .
4. IoT Venture (Case Study with CYCLE fleet) – describing benefits of CAN integration in e-bike fleets: maintenance data access, remote motor disable, OTA updates .
5. HOVSCO Knowledge – “What Safety Features Do Electric Bicycles Have?” – notes on EN 15194 (EU) ensuring speed/power limits and durability, and UL 2849 (US) focusing on electrical/fire safety , as well as mention of DIN 79010 for cargo bike safety .
6. Texas Instruments App Note – “Hardware Design Considerations for an Electric Bicycle using BLDC Motor” – provided typical e-bike system block diagrams and insight into control electronics .
7. Letrigo Ebike Knowledge – “E-bike Display Wiring Explained” – details on wiring, connectors (Higo/Julet) and cautions that no universal wiring standard exists, emphasizing proper matching of connections and robust wiring for signal integrity .
8. EnergyBus Standard – Introduction from Kvaser – describing EnergyBus as an open CANopen-based standard for LEV components to ensure compatibility and safety across manufacturers .