Disconnect and reconnect battery Then, Update firmware to latest version Then, Check for battery swelling Then, Battery replacement may be required
Is the E21 error serious on Xiaomi?
The E21 error (Battery Communication Failure) should be addressed promptly. While some causes are minor and can be fixed at home, persistent errors may indicate hardware issues requiring professional service.
When to Seek Professional Help
If the E21 error persists after trying the above solutions, consider:
Contacting Xiaomi customer support
Visiting an authorized service center
Checking your warranty coverage for repairs or replacement
