This article explains how to troubleshoot the E28 Low Voltage Protection error on an Aventon eBike.

Use this article if your bike:

• Shows an E28 error code
• Has reduced or no motor assistance
• Powers on intermittently
• Has charging or battery-related issues

If you are unsure of your Aventon model, please confirm your model before continuing.

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

Before You Start

Please prepare the following:

• Order number
• Aventon model
• Photo or video of the E28 error code
• Photo of the display
• Photo of the battery area
• Photo of the charger and charger light
• When the issue first appeared
• Whether the bike powers on
• Whether the battery charges
• Whether the display turns on
• Whether the motor engages
• Whether the issue happened after charging, transport, storage, water exposure, crash, impact, modification, or third-party repair
• Photos of visible damage

Safety Warnings

• Do not continue riding if the battery is damaged, swollen, overheating, smoking, or has a burning smell.
• 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 E28 Low Voltage Protection error means the system has detected low battery voltage.

This may happen if:

• The battery voltage is too low
• The wrong battery is installed
• The battery is damaged
• The controller system is damaged

Possible Causes

Possible causes include:

• Battery voltage too low
• Incorrect battery installed
• Damaged battery
• Damaged controller
• Battery not fully charged

Troubleshooting Steps

Step 1 – Confirm the Correct Aventon Battery Is Installed

Check whether the correct Aventon battery for your specific bike model is being used.

Some battery types may physically fit but may not be compatible with the bike.

If yes – The correct Aventon battery is installed

Continue to Step 2.

If no – The incorrect battery is installed

Stop using the bike.

Please use the correct Aventon battery for your specific bike model.

Restart the bike and check whether the E28 error remains.

If the issue clears

The issue was likely caused by an incompatible battery.

Monitor the bike during normal use.

If the issue remains

Please contact support.

Step 2 – Fully Charge the Battery

Fully charge the battery before continuing.

After charging:

• Reinstall the battery securely
• Restart the bike
• Check whether the E28 error remains

If yes – The E28 code still appears

Continue to Step 3.

If no – The error clears

The issue was likely caused by low battery voltage.

Monitor the bike during normal use.

If the issue clears

Continue normal use and monitor the bike.

If the issue remains

Continue to Step 3.

Step 3 – Check Battery Voltage Condition

Check whether the fully charged battery appears to be operating normally.

The troubleshooting guide references the following approximate fully charged battery ranges:

• 36V battery: approximately 42V when fully charged
• 48V battery: approximately 54V when fully charged

If yes – The battery appears within the normal voltage range

The issue may involve the controller system.

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

If no – The battery appears outside the normal voltage range

Stop using the battery.

Please contact our support team with photos of the battery and charger.

If the issue clears

The issue may have been caused by low battery charge.

Monitor the bike during charging and riding.

If the issue remains

Please contact support.

Step 4 – Inspect for Visible Battery or Charging Damage

Inspect the accessible battery and charging areas for:

• Swelling
• Cracks
• Overheating
• Burning smell
• Water exposure
• Impact damage
• Damaged terminals
• Charger damage

If yes – Visible damage is found

Stop using the bike and battery immediately.

Do not continue charging or riding the bike.

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

If no – No visible damage is found

Restart the bike and check whether the E28 error returns.

If the issue remains

The issue may involve the battery or controller system.

Please contact support.

When To Contact Support

Please contact support if:

• The E28 error remains after completing these checks
• The battery does not charge
• The bike does not power on
• The display does not turn on
• There is visible battery or charger damage
• The battery overheats, swells, smokes, or smells burnt
• The bike has been exposed to water, crash, impact, transport damage, modification, 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 E28 error code
• Photo of the display
• Photo of the battery area
• Photo of the charger and charger light
• Photos of visible damage
• Confirmation of whether the bike powers on
• Confirmation of whether the battery charges
• Confirmation of whether the display turns on
• Confirmation of whether the motor engages
• Confirmation of whether the correct Aventon battery is installed
• Confirmation of whether the issue happened after charging, transport, water exposure, crash, impact, modification, or third-party repair
• Confirmation of the troubleshooting steps already completed

Important Safety Notes

• Do not continue riding if the E28 error remains.
• Do not ride the bike if the battery is overheating, swollen, smoking, or visibly damaged.
• Do not open the battery, controller, or sealed electrical components.
• Do not force connectors.
• Do not work on wiring while the bike is powered on or connected to the charger.
• Contact support if you are unsure.