ASI BAC355 Motor Controller – Sensorless FOC Inverter 24-52V, 55A

The ASI BAC355 motor controller is a sub-compact AC motor controller (inverter) built for high-power electric bikes and light electric vehicles. It fits Sur-Ron and Talaria class electric motorcycles, performance e-bikes and powerful electric scooters. Accelerated Systems Inc., a Canadian motor control electronics manufacturer, designs and builds it.

This controller operates across a 24-52 V range. Furthermore, it delivers 55 A continuous and 75 A peak current while meeting the IP65 protection rating. Field oriented control (FOC) governs phase currents, so the motor turns smoothly across the entire speed range.

ASI’s proprietary adaptive sensorless algorithm removes the need for Hall position sensors. In addition, the controller auto-tunes itself to the connected motor. As a result, wiring stays simpler and setup takes less time. This product suits experienced builders and workshops that assemble or upgrade electric drivetrains.

Key Benefits

• Sensorless operation – the ASI adaptive algorithm runs without Hall position sensors, which simplifies installation.
• Field oriented control – phase currents are managed precisely, so the motor spins evenly through every RPM band.
• Up to 120% torque – the controller reaches up to 120% of the motor’s rated stall (starting) torque.
• Automatic tuning – the unit adapts itself to the parameters of the connected motor.
• Adaptive sensorless start – the startup routine adjusts to load and motor characteristics.
• Sub-compact housing – 75 A peak current comes from a very small enclosure, so it fits where standard high-power controllers will not.
• IP65 sealing – with sealed connectors the assembly reaches IP67.
• TTL and Bluetooth protocols – wired TTL communication and Bluetooth are both supported.
• 100% EOL load testing – every controller is tested under load at the end of production.

Who Is This For?

This controller targets the top commercial tier of electric bicycles. Moreover, it works well in light electric vehicles. Typical builds include Sur-Ron and Talaria class electric motorcycles, high-output e-bikes and powerful electric scooters.

The 24-52 V range covers 24 V, 36 V, 48 V and 52 V battery systems. Therefore, the unit matches drivetrains in the 250-1000 W class. It drives brushless DC (BLDC) and permanent magnet synchronous (PMSM) motors alike.

Both hub motors and mid-drive units are supported. Experienced mechanics and workshops are the intended audience. The seller configures the controller parameters, so a remote programming session is required after purchase.

Technical Specifications

Why Choose the ASI BAC355?

Power density is the first differentiator. The 75 A peak rating comes from a housing smaller than typical controllers of the same current class. Consequently, it slots into the tight frame cavities of Sur-Ron and Talaria class machines.

Sensorless startup is the second differentiator. Because the adaptive algorithm handles rotor position, Hall sensor wiring and its failure points disappear from the build. Meanwhile, automatic tuning matches the controller to the motor without lengthy manual parameter entry.

Build validation is the third. Each unit passes a 100% end-of-line test under load before shipping. On top of that, IP65 sealing protects the electronics, and sealed connectors raise the assembly to IP67.

Frequently Asked Questions

Does the ASI BAC355 fit Sur-Ron and Talaria builds?

• Yes, it is commonly used in Sur-Ron and Talaria class light electric motorcycles.
• The sub-compact housing fits narrow frame cavities where larger controllers do not.

Do I need Hall sensors with this controller?

• No, the ASI adaptive sensorless algorithm handles rotor position on its own.
• The startup routine adapts to load and motor characteristics.

Which battery voltages are supported?

• The controller operates from 24 V to 52 V.
• That range covers 24 V, 36 V, 48 V and 52 V packs.

What motors work with the BAC355?

• It drives BLDC and PMSM motors.
• Hub motors and mid-drive units are both supported.

How much current does it deliver?

• 55 A rated current and 75 A peak current.
• Torque reaches up to 120% of the motor’s rated stall torque.

Is a wiring harness included?

• No, the harness is purchased separately.
• BACDoor login credentials are not supplied with the controller.

How is the controller configured?

• The seller sets the parameters, so a remote programming session is required.
• Communication runs over wired TTL or Bluetooth.

How weatherproof is this controller for e-motorcycle use?

• The housing meets IP65.
• With sealed connectors the installation reaches IP67, which suits Sur-Ron and Talaria trail riding.

The ASI BAC355 packs 55 A continuous and 75 A peak output into a sub-compact enclosure with vector control, adaptive sensorless startup and automatic motor tuning. It is a special order item, and the wiring harness is sold separately.