This article explains how to troubleshoot the W04 Low Temperature Charging Protection warning on an Aventon eBike.

Use this article if your bike:

• Shows a W04 warning code
• Stops charging in cold conditions
• Displays a low temperature charging warning
• Does not charge normally after being stored in a cold environment

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

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

Before You Start

Please prepare the following:

• Order number
• Aventon model
• Photo or video of the W04 warning code
• 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 charger light changes during charging
• Whether the issue happened after cold weather storage, transport, water exposure, crash, impact, modification, or third-party repair
• Photos of visible damage

Safety Warnings

• Do not charge the battery if it is visibly damaged, swollen, overheating, or leaking.
• Do not continue charging if there is a burning smell, smoke, or excessive heat.
• 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 Warning Means

The W04 Low Temperature Charging Protection warning means the battery temperature is too low for safe charging.

The bike may temporarily stop charging to help protect the battery.

Possible Causes

Possible causes include:

• Ambient temperature is too low
• Battery temperature is too low
• Damaged battery

Troubleshooting Steps

Step 1 – Move the Battery to a Warmer Environment

Stop charging the bike before continuing.

Place the battery in an environment between:

• 32°F to 104°F
• 0°C to 40°C

Leave the battery in this environment for 2 hours.

After 2 hours:

• Reconnect the charger
• Attempt to charge the battery again
• Check whether the W04 warning remains

If yes – The W04 warning still appears

Continue to Step 2.

If no – The warning clears

The issue was likely caused by charging the battery in a low temperature environment.

Continue charging the battery within the recommended temperature range.

If the issue clears

Monitor the battery during future charging.

If the issue remains

Continue to Step 2.

Step 2 – Check Whether the Warning Persists

After warming the battery and reconnecting the charger, check whether:

• The battery charges normally
• The charger light changes correctly
• The W04 warning returns

If yes – The W04 warning still appears

The issue may involve the battery system.

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

If no – The warning no longer appears

The issue was likely caused by temporary low battery temperature conditions.

Continue monitoring the bike during charging.

Step 3 – Inspect the Battery for Visible Damage

Inspect the battery for:

• Cracks
• Swelling
• Water exposure
• Burning smell
• Overheating
• Physical damage

If yes – Visible damage is found

Stop using the battery immediately.

Do not continue charging or riding the bike.

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

If no – No visible damage is found

Reconnect the charger and check whether the battery charges normally.

If the issue remains

The battery system may require further inspection.

Please contact support.

Step 4 – Check Charging Conditions

Check whether the issue happened:

• During cold weather
• After storing the bike in a cold environment
• After transporting the battery in low temperatures

If yes

Allow the battery to reach room temperature before charging.

Avoid charging the battery below 0°C (32°F).

If no

The battery system may require further inspection.

Please contact support.

If the issue remains

Please contact support.

When To Contact Support

Please contact support if:

• The W04 warning remains after completing these checks
• The battery does not charge
• The charger light does not respond normally
• The battery shows visible damage or swelling
• The battery overheats during charging
• 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 W04 warning code
• 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 charger light changes during charging
• Confirmation of the charging temperature conditions
• Confirmation of whether the issue happened after cold weather storage, water exposure, crash, impact, modification, or third-party repair
• Confirmation of the troubleshooting steps already completed

Important Safety Notes

• Do not continue charging if the W04 warning remains.
• Do not use the bike if the battery is overheating, swollen, smoking, leaking, or visibly damaged.
• Do not open the battery, charger, 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.