Whether you are encountering a time/date reset issue after every power outage or looking for uninterrupted battery backup solutions for your Dahua surveillance recorder, proper battery maintenance is crucial for continuous, reliable recording.

This guide covers replacing the internal motherboard battery (RTC CMOS) as well as selecting the right external UPS battery backup system.

1. Internal CMOS Battery Replacement (Fixing Time/Date Resets)

If your Dahua DVR or NVR repeatedly resets its system time to a default year (such as 2000 or 2015) whenever it loses power, the internal Real-Time Clock (RTC) coin cell battery on the motherboard has drained and needs replacement.

Battery SpecificationBattery TypeTypical LifespanPrimary Function
CR2032 Coin Cell3V Lithium Battery3 – 5 YearsPreserves internal system clock, calendar, and BIOS settings during power cuts

Steps to Replace the Internal Battery:

  1. Power Down & Unplug: Disconnect the main power adapter and turn off the recorder.
  2. Open the Chassis: Remove the outer metal cover screws located on the sides and back panel.
  3. Locate the Coin Cell: Find the circular CR2032 battery slot on the main circuit board.
  4. Swap the Battery: Gently press the metal retaining clip to pop out the old battery and insert a fresh CR2032 cell (+ side facing up).
  5. Reassemble & Set Time: Close the casing, reconnect power, and update the time/date via the system menu or DMSS app.

2. External UPS Battery Backup for Continuous Surveillance

To prevent video loss during mains power failures or load shedding, an external Uninterruptible Power Supply (UPS) is required for both the recorder and connected PoE cameras.

  • Line-Interactive UPS (600VA – 1500VA): Recommended for standard 4 to 16 channel standalone NVR/DVR setups to provide 30–90 minutes of runtime.
  • Pure Sine Wave UPS: Ideal for larger systems with multiple PoE switches and high-wattage PTZ cameras to ensure stable power delivery.
  • 12V DC UPS Power Supply: Provides direct 12V DC backup power via rechargeable lead-acid or lithium-ion batteries without needing an inverter stage.

Conclusion

Replacing the internal CR2032 battery ensures that your Dahua DVR/NVR retains accurate timestamps—which are vital for legal evidence and playback searches. Pairing your recorder with an external UPS battery backup guarantees zero downtime and keeps your security system active even during complete power failures.

Need Assistance Choosing the Right Surveillance System?

Navigating security camera options and configurations can be complex. Whether you are looking to secure your home or upgrade your business coverage, our technical specialists are ready to help you select and deploy the ideal Dahua security solutions tailored to your needs and budget.

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