This article explains how to troubleshoot the E141 Battery Unlock Failure error on Aventon eBikes fitted with an ACU/ECU (Aventon Control Unit).

Use this article if your bike:

• Shows an E141 error code
• Has battery lock or unlock issues
• Does not recognise the battery correctly
• Displays a battery unlock warning during startup or riding

If you are unsure whether your bike uses an ACU/ECU system, please confirm your Aventon model before continuing.

Stop troubleshooting immediately if anything looks unsafe, damaged, overheated, or smells burnt.

Before You Start

Please prepare the following:

• Order number
• Aventon model
• Photo or video of the E141 error code
• Photo of the battery installed in the frame
• Photo of the battery lock area
• Screenshot of the Aventon App firmware version, if available
• When the issue first appeared
• Whether the bike powers on
• Whether the display turns on
• Whether the battery locks securely
• Whether other controller error codes are displayed
• Whether the issue happened after transport, storage, water exposure, crash, impact, modification, firmware update, or third-party repair
• Photos of visible damage

Safety Warnings

• Do not continue riding if the battery is loose or not securely locked into place.
• Ensure the bike is fully stopped before performing these checks.
• Do not rotate the pedals while troubleshooting this issue.
• Do not use the bike if there is visible battery, frame, or lock damage.
• Do not open sealed electrical components.
• Do not work on wiring while the bike is powered on or charging.
• Stop and contact support if you are unsure.

What This Error Means

The E141 Battery Unlock Failure error means the bike cannot correctly confirm the battery lock or unlock status.

This may happen if:

• The battery is not fully installed
• The bike or pedals are moving during startup
• The controller is disconnected or damaged
• The ECU software is outdated
• The battery lock is damaged
• The ECU is damaged

Possible Causes

Possible causes include:

• Battery not installed correctly
• Bike or pedals moving during startup
• Controller disconnected or damaged
• ECU software bug or outdated software
• Damaged battery lock
• Damaged ECU

Troubleshooting Steps

Step 1 – Ensure the Battery Is Fully Installed

Press the battery firmly into the frame.

Confirm:

• The battery is fully seated
• The battery locks securely into place
• The battery sits flush with the frame

Ensure:

• The bike is completely stopped
• The pedals are not rotating

Update the ECU software to the latest version using the Aventon App if available.

Restart the bike and check whether the E141 error remains.

If yes – The E141 error still appears

Continue to Step 2.

If no – The error clears

The issue was likely caused by the battery not being fully seated, movement during startup, or outdated ECU software.

Monitor the bike during normal use.

If the issue clears

Continue normal use and monitor the bike.

If the issue remains

Continue to Step 2.

Step 2 – Check for Other Controller Error Codes

Check whether any additional controller error codes are displayed.

If yes – Other controller error codes are present

Follow the troubleshooting process for the additional controller error codes.

Please contact our support team with:

• Photos of all error codes
• Photos of the display
• Photos of accessible connectors and wiring

If no – No additional controller error codes are present

Continue to Step 3.

If the issue remains

Continue to Step 3.

Step 3 – Inspect the Battery Lock Assembly

Inspect the battery terminal and lock assembly.

Loosen the mounting bolts if needed, then:

• Adjust the alignment of the terminal and lock assembly
• Retighten the mounting bolts securely

Restart the bike and check whether the E141 error remains.

If yes – The E141 error still appears

Continue to Step 4.

If no – The error clears

The issue was likely caused by battery lock or terminal alignment.

Monitor the bike during normal use.

If the issue clears

Continue normal use and monitor the bike.

If the issue remains

Continue to Step 4.

Step 4 – Inspect the Battery Lock Area for Visible Damage

Inspect the battery lock area for:

• Visible damage
• Loose fitment
• Damage around the mounting area
• Water exposure
• Impact damage

If yes – Visible damage is found

Stop using the bike immediately.

Please contact our support team with photos/videos of the battery lock area.

If no – No visible damage is found

Restart the bike and check whether the E141 error returns.

If the issue remains

Continue to Step 5.

Step 5 – Check Whether the Error Persists

After reinstalling the battery, updating the ECU software, and checking the lock assembly, check whether:

• The battery locks securely
• The bike powers on normally
• The display operates normally
• The E141 error returns

If yes – The E141 error still appears

The issue may involve:

• The battery lock system
• Controller communication
• ECU operation

Please contact our support team with the photos/videos listed below so we can review the next step.

If no – The error no longer appears

The issue was likely caused by improper battery installation, alignment, or outdated software.

Continue monitoring the bike during use.

Step 6 – Check for Battery Movement

With the bike powered off, check whether the battery:

• Moves excessively in the frame
• Feels loose after locking
• Does not sit flush with the frame

If yes

Do not continue riding the bike.

Please contact support with photos/videos of the battery fitment and lock area.

If no

Restart the bike and monitor whether the E141 error returns.

If the issue remains

Please contact support.

When To Contact Support

Please contact support if:

• The E141 error remains after completing these checks
• The battery does not lock securely
• The battery moves excessively in the frame
• There is visible battery lock or terminal damage
• Other controller error codes are present
• The bike does not power on correctly
• Firmware updates fail repeatedly
• The bike has been exposed to water, crash, impact, transport damage, modification, firmware issues, or third-party repair
• You are unsure how to safely complete a step

If the issue remains after these steps, please contact our support team and include the photos/videos listed below.

What To Send Support

Please send:

• Order number
• Aventon model
• Photo/video of the E141 error code
• Photo of the battery installed in the frame
• Photo/video of the battery lock area
• Screenshot of the Aventon App firmware version
• Photos of visible damage
• Confirmation of whether the bike powers on
• Confirmation of whether the display turns on
• Confirmation of whether the battery locks securely
• Confirmation of whether the battery sits flush with the frame
• Confirmation of whether other controller error codes are displayed
• Confirmation of whether firmware updates complete successfully
• Confirmation of whether the issue happened after water exposure, crash, impact, modification, firmware update, or third-party repair
• Confirmation of the troubleshooting steps already completed

Important Safety Notes

• Do not continue riding if the E141 error remains.
• Do not ride the bike if the battery is loose or not securely locked into place.
• Ensure the bike is fully stopped and pedals are not rotating during startup checks.
• Do not use the bike if there is visible damage, overheating, smoke, or a burning smell.
• Do not open the ECU, battery, controller, or sealed electrical components.
• Do not force the battery into the frame.
• Do not work on wiring while the bike is powered on or connected to the charger.
• Contact support if you are unsure.