ASI BAC855 BBSHD Plug & Play Controller for Bafang BBSHD – 48-72V, 4000W FOC

The ASI BAC855 BBSHD P&P is a plug and play motor controller built specifically for the Bafang BBSHD mid-drive motor. It replaces the original Bafang controller and runs on 48V, 52V, 60V and 72V battery systems. No extra programming is needed when you change pack voltage. Every connector matches the original Bafang BBSHD motor and its factory wiring harness.

The controller arrives pre-programmed for field-oriented control, better known as FOC, and handles up to 4000W. Because the plugs are already correct, installation needs no soldering and no re-crimping of terminals. You will not cut a single wire. That makes this a direct swap rather than a conversion project.

This kit has been developed and refined over more than seven years. As a result, it delivers stable operation and strong torque from a standstill. Pair it with either the Bafang 750C display or the Eggrider V2 display, and you control power levels straight from the handlebar.

Key Benefits

• Plug and play connectors – every plug mates with the original Bafang BBSHD motor, so soldering is unnecessary.
• 48-72V battery compatibility – the same unit runs 48V, 52V, 60V and 72V packs without reprogramming.
• 4000W output – four kilowatts on tap, while the stock BBSHD controller sits in the 1000W class.
• FOC sinusoidal control – vector control keeps the motor quieter and acceleration smoother.
• Motor temperature sensor – the 2024 model tracks motor heat and prevents overheating.
• Gear shift sensor support – power drops briefly during a shift, which protects your drivetrain.
• Adjustable assist levels – level 1 gives 37%, level 2 gives 65% and level 3 gives 100% of controller power.
• 6V 500mA light output – your front light draws power directly from the controller.
• Battery wear protection – output adjusts automatically as the state of charge drops.

Who Is This For

This controller suits riders who already own a Bafang BBSHD mid-drive motor mounted at the bottom bracket. It is a controller only. It is not a motor, and it is not a complete conversion kit. Therefore you must have a working BBSHD unit before fitting it.

On the display side, choose either the Bafang 750C or the Eggrider V2. One display is included, so you select which one during ordering. On the battery side, 48V, 52V, 60V and 72V systems all work. Future battery upgrades within that same voltage range work too, which means the controller stays with you as your build evolves.

Since the unit is set up for 4000W, it is intended for off-road riding or use on closed private land. European pedelec rules limit assistance to 250W and 25 km/h, so this power level does not belong on public roads.

What’s in the Box

• 1x ASI BAC855 controller
• 1x set of OEM cables, 30 cm long – custom lengths are available on request, so contact us before ordering
• 1x display: 750C or Eggrider V2 (choose one)
• 1x controller bracket
• 1x motor cover

Technical Specifications

Why Choose the ASI BAC855

The controller ships pre-programmed. Consequently, you never need to reflash it, even when you move from a 48V pack to a 72V pack. The same unit stays in your build through every voltage upgrade in that range.

Power is easy to tune from the display itself. Each assist level can be set as a percentage, so you can match the ride feel to the terrain and to your own style. You can also set wheel size for accurate speed readings.

Seven years of development show up in how the motor behaves. Torque builds immediately from a standstill, and the sinusoidal waveform keeps noise down at cruising speed. Meanwhile the temperature sensor watches the motor in the background, and the shift sensor eases power during gear changes.

Frequently Asked Questions

Will this controller fit my Bafang BBSHD motor?

• Yes. All connectors match the original Bafang BBSHD motor and its wiring harness.
• No cutting, crimping or soldering is required during installation.

Do I need to reprogram it for a different battery voltage?

• No. The unit arrives programmed for 48V, 52V, 60V and 72V systems.
• You can move to a higher voltage pack later and keep the same controller.

Is this a complete motor kit?

• No. This is a controller, not a motor and not a conversion kit.
• You need a working Bafang BBSHD mid-drive motor already fitted to the bike.

Which display should I choose?

• The controller works with the Bafang 750C display or the Eggrider V2 display.
• One display is included, so you pick a single option when ordering.

How much power does it deliver?

• Up to 4000W, compared with roughly 1000W from the stock BBSHD controller.
• Assist levels are set to 37%, 65% and 100% of that output.

Can I use it on public roads?

• European pedelec rules cap assistance at 250W and 25 km/h.
• This setup is intended for off-road use or closed private property.

Does it protect the motor from overheating?

• Yes. The 2024 model monitors motor temperature and limits output when heat rises.
• Battery wear protection also trims power as the charge level falls.

Can the cable length be changed?

• Standard OEM cables measure 30 cm.
• Custom lengths are possible, so get in touch before you order.

With a 300 g controller measuring just 81 x 55 x 39 mm, the ASI BAC855 turns a stock BBSHD into a four-kilowatt drivetrain without a single soldered joint. The bracket and motor cover are included, and the display of your choice ships in the same box.