ASI BAC4000 Motor Controller – 380A FOC Controller for Sur-Ron & Talaria

The ASI BAC4000 is an ultra-compact AC motor controller built for high-power electric bikes and electric motorcycles. It was designed for machines such as the Sur-Ron Light Bee and the Talaria Sting. The unit operates across a 36-72 V range and delivers 380 A of rated current. Peak output reaches 430 A when the rider demands it.

Inside, the controller runs field-oriented control together with an adaptive sensorless algorithm developed by ASI. As a result, the motor spins without position sensors while torque control stays precise. Auto-tuning is built in, so the controller identifies motor parameters on its own. Thanks to that combination, the BAC4000 reaches up to 120 % of rated locked-rotor torque without a complex sensor setup.

This model sits at the top commercial tier of electric bike drive electronics. It suits riders and workshops assembling a power upgrade package rather than replacing a stock part. Configuration happens over TTL or Bluetooth, and the sealed housing carries an IP65 rating.

Key Benefits

• 380 A rated current – continuous current delivery during sustained high-load riding.
• 430 A peak current – extra headroom for hard launches and steep climbs.
• 36-72 V voltage range – works with a wide spread of battery pack configurations.
• Adaptive sensorless startup – the motor moves off without any Hall sensor signal.
• Automatic tuning – the controller determines motor parameters by itself.
• Up to 120 % starting torque – more pull than the motor’s rated figure suggests.
• IP65 protection rating – IP67 is achievable when sealed connectors are fitted.
• TTL and Bluetooth protocols – parameters change over a wired or wireless link.
• Ultra-compact housing – fits more easily into tight frame cavities.
• 100 % end-of-line load testing – every unit is verified at the factory.

Who Is This Controller For?

The BAC4000 targets high-power electric bikes and electric motorcycles. In practice, it is most often fitted to the Sur-Ron Light Bee, the Sur-Ron Light Bee X, the Light Bee L1E and Talaria Sting class machines. It also works in custom power-increase builds using brushless permanent-magnet synchronous motors.

This controller is aimed at experienced users and workshops. Above all, it serves riders assembling an upgrade kit who specifically want 380 A class current. In addition, it fits commercial-grade electric bike platforms that need more output than a factory controller can supply.

The BAC4000 is not a production spare part for a bicycle. Rather, it is a power electronics component. Therefore it requires dedicated mounting work and proper configuration before the first ride.

Important Information Before Purchase

• The ASI BAC4000 wiring harness is sold separately.
• BacDoor app login credentials are not supplied with the controller.
• A remote programming session must be purchased alongside this item.
• Contact us regarding quantity and conditions.
• Warranty does not apply when the controller replaces a unit in a system or upgrade kit not purchased from FabiRide.

Technical Specifications

Why Choose the ASI BAC4000?

The defining difference of this model is current. A 380 A rated figure with a 430 A ceiling puts it well above what a factory Sur-Ron or Talaria controller supplies. Consequently, builders gain real headroom for launches and long climbs rather than a marginal bump.

The second differentiator is the control strategy. Field-oriented control keeps torque accurate throughout the rev range. Meanwhile, the adaptive sensorless algorithm removes the dependence on Hall sensors entirely. Auto-tuning then handles motor identification, which shortens commissioning on a custom build.

Packaging matters too. The ultra-compact case slots into frame space that larger power electronics cannot use. Furthermore, every unit passes a 100 % end-of-line test under load before it leaves the factory, and the IP65 housing steps up to IP67 once sealed connectors are used.

Frequently Asked Questions

Does the ASI BAC4000 fit a Sur-Ron Light Bee?

• Yes. The Sur-Ron Light Bee, Light Bee X and Light Bee L1E are among its most common applications.
• Mounting and configuration work is required, since this is not a plug-in stock replacement.

Will this controller work on a Talaria Sting?

• Yes. Talaria Sting class machines fall within the intended application range.
• The 36-72 V window covers the battery configurations typically used on these builds.

Is a wiring harness included?

• No. The ASI BAC4000 wiring harness is sold separately.

Do I need Hall sensors for the motor to start?

• No. The adaptive sensorless algorithm starts the motor without position sensor feedback.
• Torque control remains precise thanks to field-oriented control.

How are parameters configured?

• Through TTL over a wired connection or through Bluetooth wirelessly.
• BacDoor app login credentials are not supplied, so a remote programming session must be purchased with this item.

How much starting torque does it deliver?

• Up to 120 % of the rated locked-rotor torque figure.
• Auto-tuning sets the motor parameters that make this possible.

How well is the housing protected?

• The case meets IP65. With sealed connectors fitted, IP67 is achievable.

Is every unit tested?

• Yes. Each controller passes a 100 % end-of-line test under load at the factory.

The ASI BAC4000 gives experienced builders and workshops a 380 A class drive controller in a housing small enough for tight frames. Plan the harness and the programming session into your build, and this controller becomes the core of a serious Sur-Ron or Talaria power upgrade.