Guides and advice

Sudden cut-off at full acceleration? The battery management system (BMS) is often protecting itself. Here's how it works, how to identify it, and how to avoid it.

Here's what a Battery Management System (BMS) does for an electric scooter battery: It provides protection, uses cutoff transistors, balances the cells (either passively or actively), and explains the benefits of a connected BMS.

Differential pair, 120-ohm terminations, identifiers, and priority: the CAN bus that connects controllers, BMS (Battery Management Systems), and displays, and how to wire it.

Cable sizing, AWG and mm², voltage drop, heat generation, crimping, and connectors: determining the appropriate power cable specifications for an electric vehicle.

To control a motor, the controller needs to know the position of the rotor. Hall sensors, encoders, resolvers, and sensorless control are simply different ways to achieve this.

Why does an electric motor reach a speed limit? How does "defilming" push this limit? What is the impact on current draw and heat generation? And what are the risks involved?

Copper losses, iron losses, magnet temperature, and winding temperature: where does the heat in an electric scooter motor come from, and how can you prevent it from being damaged?

Voltage, capacity, discharge current, internal resistance, lifespan: understanding the figures for a lithium battery cell, and how to use them to determine the specifications of a battery pack.

How does the motor transform into a brake and a generator? How much energy do we actually recover? And why does electric braking weaken when the battery is full?

What changes with the switching frequency of a controller: losses in the transistors, current ripple, audible noise, and control precision.

Three-phase bridge, MOSFET transistors, gate drivers, dead time, current measurement, capacitors, and cooling: these are the components found in a motor controller.

The Kv value determines the speed, the Kt value determines the torque per amp, and the number of poles determines the electrical frequency. Here's how to understand, calculate, and choose between High Speed and High Torque configurations.

Eight bridge states, six active vectors, and two zero vectors: how Space Vector PWM (SVPWM) generates the desired voltage, and why it draws 15% more current.

Why electric cars use interior permanent magnet (IPM) motors: A simple explanation of reluctance torque, saliency, MTPA, and demagnetization.

Permanent Magnet Synchronous Motor (PMSM) and Brushless DC Motor (BLDC): Same construction, different voltage waveforms, and what that means for control.

How does a controller estimate the rotor position without a sensor? It uses the voltage produced by the motor, a flux observer, and limitations at low speeds.

How does a controller correct the current thousands of times per second? The role of the proportional and integral terms, gain calculation, and saturation.

CAN wiring, identifiers, shared control, traction control: how to make two VESC controllers work together on a dual-motor scooter.

ABS_OVER_CURRENT, DRV, UNDER_VOLTAGE, OVER_TEMP: What these VESC controller error messages mean, how to read them in the VESC Tool, and how to fix them.

Field Weakening Current Max, Duty Start, Ramp Time: How to enable field weakening in VESC Tool, what benefits it provides in terms of speed, and the risks to be aware of.

Resistance, inductance, flux, sensors: what the FOC detection feature in VESC Tool measures, how to successfully perform it with a raised motor bell, and how to interpret the results.

Whether it's open-source or proprietary software, settings, diagnostics, or intended use: here's what differentiates VESC, Fardriver, Kelly, and the original controllers, to help you choose the right one.

Throttle and brake control on VESC: ADC application, voltage ranges, curves, ramps, and regenerative braking, all adjustable step-by-step within the VESC Tool.

Motor Current Max, Battery Current Max, Absolute Maximum Current: What each of these current limits does in the VESC Tool, and how to adjust them safely.

VESC Tool tutorial in French: download, USB or Bluetooth connection, firmware update, and saving settings before making any changes.

Maintenance symbol or engine code on a Dualtron: how to read the error message displayed and what to check in order.

Motor that vibrates, growls, or hesitates when starting: how to test the Hall sensors, the phases, and the controller to find the root cause.

Four-piston calipers, thick rotors, aviation-grade hoses, and brake pads: how to properly size the braking system for a fast and heavy electric scooter.

More cells in series mean higher speed: what a higher voltage battery offers, and everything you need to check before installing it.

Brakes, tires, steering, battery, motors, controllers: what's the best order to upgrade a Dualtron Thunder to make it faster without compromising its reliability?

How to prepare a Nami Burn-E: Upgrading the battery for higher output, installing larger motors with spacers, replacing the steering column with a titanium one, upgrading the wiring, and improving the brakes.

Weped FS, SST, SSGT, or GTS: What can be installed without modification, batteries with higher discharge rates, and what our track-ready preparations have revealed.

Flexing, loosening, and bending: the weak point of the Teverun Fighter's frame. How to address this issue and the checks to perform on a powerful machine.

25 km/h on public roads, penalties for tampering with speed limits, insurance: what French law says about electric scooters, and where you can legally ride fast.

Torque, speed, efficiency, and heat: how a dynamometer measures what an electric motor *actually* does, and why specifications alone are not enough.

Sur-Ron, pit bike, lightweight electric motorcycle: what the controller does, the criteria for choosing one, and what to check with the motor and battery.

Converting a kart for leisure, rental, or competition: how to electrify a kart, choose the right motor, controller, and battery, and avoid common mistakes.

Formula Student, Shell Eco-marathon, research vehicle: how a student team chooses a motor, controller, battery, and telemetry system, and the pitfalls to avoid.

Pleasure boat, tender, rental fleet: the requirements for a boating license, and how to choose a motor, controller, and battery for electric propulsion.

Weed removal robot, harvesting assistant, tracked transporter: how to choose motors, controllers, and batteries for an electric agricultural vehicle.

Converting a motorcycle, scooter, or moped to electric power: what the 2020 decree says, the role of the certified installer, and the technical steps involved.

Bending, loosening, and flexing: why original steering columns weaken, what a Grade 9 titanium steering column offers, and compatible models.

Teverun Fighter Supreme or Dualtron Thunder 3: Power, battery, steering, parts, and preparation. A comparison from a workshop that works on both.

On December 17, 2023, the awards ceremony for the Île-de-France electric scooter league took place. Rage Mechanics was on every podium!