Views: 0 Author: Site Editor Publish Time: 2026-09-02 Origin: Site
When the power goes out, low-power devices such as routers, ONU/ONTs, CCTV cameras and wireless APs may lose power immediately, causing Wi-Fi interruptions, network downtime or security monitoring failures.
So, what problems can a DC UPS solve? How long can it run your devices? And how do you choose the right one?
The following 10 FAQs answer the most common questions about using a DC UPS during power outages.
Because the router and ONU/ONT also need continuous power.
Even if your smartphone or laptop still has battery power, the internet connection may stop working if the router or ONU loses power.
A DC UPS can continue supplying backup power to compatible network devices when the main power fails, helping keep Wi-Fi and network connectivity available.
However, if the ISP's network line or upstream network itself experiences an outage, a DC UPS cannot restore the internet connection.
A DC UPS is mainly designed for low-power DC devices, such as:
Routers
ONU/ONTs
CCTV cameras
Wireless APs
Optical network terminals
Some network switches
Other compatible DC devices
Before connecting a device, make sure its input voltage, power consumption, connector and polarity are compatible with the DC UPS.
First, check the input specifications on the router's power adapter.
For example:
12V × 1A = 12W
If the DC UPS supports 12V output and has a maximum output power higher than 12W, and the connector and polarity are compatible, it can meet the router's basic power requirements.
Therefore, choosing a DC UPS is not only about battery capacity. You also need to check the output voltage and maximum output power.
Yes, but you need to calculate the total power consumption of both devices.
For example:
Router: 12W
ONU: 6W
Total power consumption:
12W + 6W = 18W
If the DC UPS has a maximum output power of 18W, the combined load has already reached its rated output limit. In practical applications, it is generally better to choose a model with some additional power capacity.
You also need to make sure that the required output voltage and connectors are compatible with both devices.
Yes, but the appropriate DC UPS should be selected according to the camera's power supply requirements.
For example:
12V CCTV camera → Choose a DC UPS with compatible 12V output
PoE camera → Choose a DC UPS that supports the required PoE output
If multiple cameras are connected, you also need to calculate their total power consumption.
For example, if two cameras each consume 8W:
8W × 2 = 16W
The maximum output power of the UPS should therefore be sufficient to support at least a 16W load.
Runtime mainly depends on battery energy, device power consumption and system efficiency.
You can use the following formula for a basic estimate:
Estimated Runtime ≈ Battery Energy (Wh) × Efficiency ÷ Device Power (W)
For example, suppose a DC UPS has a battery energy of 38.48Wh and an estimated efficiency of 90%.
For a 12W router:
38.48 × 90% ÷ 12 ≈ 2.9 hours
For a 24W device:
38.48 × 90% ÷ 24 ≈ 1.4 hours
Actual runtime may vary depending on battery condition, temperature, load fluctuations and system efficiency.
You can estimate the required battery energy based on the device's power consumption and the desired backup time.
For example, if a device consumes:
12W
and you want it to run for:
4 hours
The theoretical energy requirement is:
12W × 4h = 48Wh
If the system efficiency is assumed to be 90%:
48Wh ÷ 90% ≈ 53.3Wh
Therefore, when choosing a DC UPS, battery capacity should be determined based on the actual load and required backup time, rather than simply choosing the highest mAh rating.
Not necessarily.
mAh is one way of expressing battery capacity, but batteries with different voltages can store different amounts of energy even if they have the same mAh rating.
A more direct calculation is:
Wh = Voltage (V) × Capacity (Ah)
For example:
7.4V × 5.2Ah = 38.48Wh
Therefore, when comparing different DC UPS systems, it is better to consider:
Wh + Device Power Consumption + System Efficiency
rather than comparing mAh alone.
The main difference is their output type and the equipment they are designed to power.
Feature | DC UPS | AC UPS |
|---|---|---|
Output | DC | AC |
Common devices | Routers, ONU/ONTs, CCTV, APs | Computers, servers, office equipment |
Typical characteristics | Compact and designed for low-power devices | Wider power range |
Main application | Backup for network and security devices | Backup for PCs and other AC-powered equipment |
If your main goal is to keep routers, ONU/ONTs or CCTV cameras running, a DC UPS is usually a more direct solution.
If you need backup power for computers, servers or other AC-powered equipment, an AC UPS is generally more suitable.
You can select a suitable DC UPS by checking the following specifications:
① Output Voltage
Make sure the output voltage matches your device, such as 5V, 9V, 12V, 15V or 24V.
② Maximum Output Power
Make sure the UPS can support the actual power consumption of your device.
For example, if the device requires 12W, the UPS maximum output power should not be lower than 12W.
③ Battery Energy
Pay attention to the battery's Wh rating and calculate whether it can meet your required backup time.
④ Output Connectors
Make sure the available DC, USB, Type-C or PoE outputs are compatible with your devices.
⑤ Total Power Consumption for Multiple Devices
If you plan to connect multiple devices, calculate their combined power consumption before choosing the UPS.
A DC UPS is mainly designed to solve one practical problem:
Keeping routers, ONU/ONTs, CCTV cameras and other low-power DC devices running when the main power goes out.
When choosing a DC UPS, don't focus only on battery capacity. You should also check:
Is the voltage compatible? Is the output power sufficient? Is the connector suitable? Can the battery Wh capacity provide the required backup time?
When these specifications are properly matched, a DC UPS can provide a practical backup power solution for keeping network and security devices operating during power outages.
