Keeping Your Fiber Internet Running During Power Outages
One common concern about fiber internet is its dependency on electrical power at the customer premises. Unlike old-fashioned copper phone lines that carried their own power, fiber ONTs (Optical Network Terminals) need a power outlet. When the power goes out, your fiber internet goes dark unless you have battery backup. The good news is that powering an ONT is simple and affordable.
### Understanding Your ONT's Power Requirements
A residential fiber ONT is a remarkably low-power device. Most consume between 10 and 25 watts, roughly equivalent to an LED light bulb. This low power consumption means even small battery backup solutions can keep your ONT running for extended periods.
Your WiFi router is the other essential device. Routers typically consume 10 to 20 watts for consumer models. Combined, your ONT and router need approximately 20 to 45 watts of power to maintain internet connectivity during an outage.
### UPS: The Standard Solution
An uninterruptible power supply (UPS) is the most common and practical backup power solution for fiber equipment. A UPS contains a battery that instantly takes over when utility power fails, providing seamless transition with no interruption to your internet service.
**Sizing your UPS**: To determine how long a UPS will keep your equipment running, divide the UPS battery capacity (in watt-hours) by your equipment's power consumption (in watts).
Example calculation: - ONT: 15 watts - Router: 15 watts - Total: 30 watts - UPS with 300 Wh battery: 300 / 30 = 10 hours of runtime
**Recommended UPS sizes by runtime goal**:
- **4-hour runtime**: 120-150 Wh capacity UPS. Suitable for brief weather-related outages. Price: $50-$80. - **8-hour runtime**: 250-300 Wh capacity UPS. Covers most overnight outages. Price: $80-$150. - **24-hour runtime**: 700-800 Wh capacity UPS or portable power station. Extended outage protection. Price: $200-$500.
### UPS Features to Look For
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Check My Address**Pure sine wave output**: Some ONTs and routers are sensitive to the modified sine wave output of cheaper UPS units. Pure sine wave models are more compatible and safer for sensitive electronics.
**Multiple outlets**: You need at least two battery-backed outlets (ONT and router). Additional outlets let you also power a switch, access point, or phone charger.
**USB ports**: Some UPS units include USB ports for charging phones and tablets during outages.
**Automatic restart**: After the UPS battery is depleted and power returns, the UPS should automatically restore power to connected devices without manual intervention.
**Surge protection**: A UPS that also provides surge protection handles two needs with one device.
### Portable Power Stations as Alternative
Portable power stations (like those from Jackery, EcoFlow, or Bluetti) designed for camping and outdoor use can also power fiber equipment. Their larger batteries provide extended runtime:
- A 500 Wh portable station provides approximately 16 hours for ONT + router - A 1000 Wh station provides approximately 33 hours - Many include solar panel charging for indefinite runtime with adequate sunlight
The tradeoff is cost. Portable power stations are more expensive than purpose-built UPS units for the same runtime but offer versatility for other uses.
### ISP-Provided Battery Backup
Some fiber ISPs provide battery backup units as part of their service. These provider-supplied batteries typically offer 4 to 8 hours of ONT power. Check with your provider whether battery backup is included, optional at additional cost, or not offered.
If your provider offers a battery backup option, evaluate its runtime against your needs. Provider-supplied batteries may offer less runtime than a third-party UPS at a comparable cost.
### Installation Tips
- Place the UPS near your ONT and router, with easy access for monitoring battery status - Plug only your ONT and router into the UPS battery-backed outlets (not your TV, lamp, or other non-essential devices) - Test the UPS by unplugging it from the wall and verifying your internet stays connected - Replace the UPS battery every 3 to 5 years, or when the UPS indicates battery degradation - Label the UPS outlets so no one accidentally plugs high-draw devices into the battery-backed sockets
Beyond Battery Backup
For mission-critical internet connectivity during extended outages, consider layered backup:
1. **Primary**: Fiber internet with UPS (handles outages up to 8-24 hours) 2. **Secondary**: Cellular hotspot (handles longer outages where cell towers have generator backup) 3. **Tertiary**: Starlink or fixed wireless (for rural areas where cellular coverage is limited)
Use [FiberFinder's availability tool](/availability) to identify fiber providers in your area and evaluate their battery backup options.
**Want uninterrupted fiber internet?** [Check fiber availability at your address](/availability) and pair your service with appropriate battery backup.