Is your Huawei Mate 9 Lite BLL-L21 overheating or draining battery quickly after a recent firmware update? You're not alone. Many users face this frustrating issue, especially after installing updates that conflict with background system services. Fortunately, there's a safe and proven way to resolve this using Huawei’s built-in eRecovery tool and the Test Point flashing method.
What Causes Sudden Battery Drain on Huawei BLL-L21?
- Incompatible or corrupted OTA update
- System files not properly optimized after flashing
- Background apps or services stuck in a loop
- Power management kernel issues
This is especially common in older EMUI versions. The good news is — it’s fixable!
What is eRecovery and How It Helps?
eRecovery is Huawei’s official system repair feature that downloads and reinstalls the correct firmware wirelessly or manually. If your system is unstable or draining the battery rapidly, using eRecovery in combination with the Test Point method can restore full functionality.
Using the Test Point Method for Repair
If your phone isn't entering fastboot or recovery, you can use the Test Point method to force it into EDL mode (Emergency Download Mode). Here's a quick summary:
- Open the device carefully and locate the test point.
- Short the test point while connecting USB cable to PC.
- Use the flashing tool to load board or stock firmware.
This process forces your Huawei Mate 9 Lite into a low-level download state, allowing you to reflash firmware safely.
Step-by-Step eRecovery Repair Instructions
- Boot the phone into eRecovery (Power + Volume Up if accessible).
- Choose Download Latest Version and Recovery.
- Connect to a strong Wi-Fi and wait for Huawei servers to deliver the proper firmware.
- Let the system re-install and restart the phone.
If eRecovery fails, revert to flashing stock firmware manually using test point.
Post-Repair Checklist to Prevent Future Issues
- Wipe cache partition after update
- Reset settings if battery issue persists
- Do not restore old system backups from different firmware builds
- Keep background apps limited and disable auto-sync temporarily
Common Errors and Fixes
- Phone not detected in flash tool: Check drivers and test point contact
- Battery still draining: Flash firmware again with full wipe or downgrade version
- eRecovery not working: Try board firmware flashing via USB COM mode
Disclaimer: Flashing firmware, using the test point, or modifying system partitions on Huawei devices can lead to data loss or permanent damage if not done correctly. Always use the exact firmware for your model (BLL-L21) and proceed only if you're confident. This guide is for educational purposes only. Unauthorized IMEI or network changes may be illegal in your region.
| š ️ Huawei Mate 9 Lite BLL-L21 Flashing Guide |
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| š Click here to learn full flashing steps for BLL-L21 |
| š BLL-L21C185B382 (Middle East) Official Firmware |
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| ✅ Download Stock ROM for Huawei Mate 9 Lite BLL-L21 |