Copyright © 2012 by Nobo Komagata (,

Keeping the Internet Connection during a Power Outage

Nobo Komagata

First written: November 5, 2012; Last updated: May 1, 2013


During Hurricane Sandy in 2012, we experienced five days of power outage. Since our household heavily depends on the Internet, I tried to keep it as much as possible during this time. Here is the record of what I did.

First, here is a list of devices discussed below:

Note that we do not have a landline for our phone service, which would work even during a power outage (as long as the phone wire is intact); we figured this was waste of money. In addition, we are not inclined to purchase and use a backup engine generator.

Our basic plan was to sacrifice the desk top computers and rely on the notebook computer and phones.

Disclaimer: If the reader chooses to use the information in this document, please do so at your own risk.

Step 1: Keeping FiOS ONT's Data/Internet Running during a Power Outage

Even though Verizon FiOS's ONT is backed up with a battery, it only backs up the voice capability. Since we only use the data (Internet), this is completely useless. While it is possible to add a UPS backup, there will be additional cost. Luckily, through web search, I found a way to overcome this problem. The following two articles were extremely helpful; Thank you so much!

Based on our earlier experience, I was expecting a power outage during Hurricane Sandy's passing. So, I made the modification to my ONT, following the articles.

My ONT looks like this:

When I open the top cover, it looks like this:

There is a screw behind wires, as shown in the red circle. I unscrew it and pull the cover of the box as in the following image:

At the bottom left of the box, there are several colored wires. They are Red, Black, White/Color, Solid/Color, Green, Gray, Brown, Blue, and Orange. I cut the Blue one.

That's it. I replaced the covers in the reverse order.

At around 9pm on October 29, we lost the power. I wanted to report the outage. But I suspected that PSE&G's phone lines were being overwhelmed by calls. So, I tried to report this on-line.

Now, the ONT's “battery” lamp was on (in addition to the “system” lamp). Since our UPS's for the desktop computers are not large enough, we needed to shut down our computers. Verizon router is also connected to the same UPS and needed to be shut down. At this point, I unplugged the CAT5 cable (coming from the ONT) from the router and plugged it in to the Ethernet port of our notebook.

I was able to confirm the Internet connection and report the outage. After this, we didn't use the Internet until the next morning. At around 7am the next morning (Oct. 30), about 10 hours after the outage started, I was still able to use the Internet.

Conclusion: If at least the following conditions are met, we could use the Internet for several hours after the power outage starts.

Step 2: Using Car Battery and a DC-to-AC Inverter

After a couple of hours, the ONT battery finally went out. The notebook computer's battery would not last forever either. So, the next step was to use our car's battery and a DC-to-AC inverter to run the ONT. The inverter we have is more than ten years old and has only 140W capacity.

I connected the inverter to the cigar lighter socket of my car parked on the driveway. Then, I ran a 100ft power extension cord from the car to the ONT in the garage. The ONT turned on and we were back on the Internet. Since I was worried about draining the car battery completely, I kept the engine running while using the inverter.

With this configuration, I was able to charge smart phone, cell phone, and pocket computer in the garage. However, I was unable to charge the notebook computer. I suspect that the inverter's output is not pure sine wave and the AC adapter for the notebook would not work with it. The same AC adapter didn't work with the power outlet in Boeing 777 either. So, the problem seems to be specific to the combination between our inverter and the AC adapter. I have a feeling that if a notebook computer comes with an old-fashioned transformer-type AC adapter, it might work with our inverter as well.

Luckily, after scavenging our basement, I found a universal car charger which works with the notebook. I can now charge the notebook directly on the cigar lighter socket of the car.

Conclusion: With a car and an inverter, we can keep the internet connection as long as the car battery is available.

Step 3: Using a Stand-Alone Battery

Although the arrangement in the previous section was sufficient for our purposes, it was rather inconvenient to set up the wiring and going to the car and garage to do necessary tasks, including charging devices. It is not good to keep the car idling just for a small amount of electricity usage.

The next step was to purchase a marine battery (automotive battery with screw terminals) so that we don't rely on the car battery. Although any 12 volt battery with sufficiently large capacity would do, the store person recommended a marine battery (90AH) as it has terminals for easy wire connection. It was under $100.

I placed the battery in our office so that we can charge the notebook computer right there. I also purchased cigar lighter sockets.

The inverter is connected to one of the sockets so that other devices can be charged there as well. Then, I ran the 100ft extension cord from the inverter to the ONT through the house.

With this configuration, we can charge all of the necessary devices and turn on/off the power the ONT right in our office. Since all of these devices have batteries, it is not necessary to power them all the time. For example, if we power the ONT twice in the morning and in the evening for a few hours each, we can use the Internet most of our waking hours. Since the ONT draws about 1.5A, if the ONT is the only device connected to the battery, the battery would last about 2.5days. After starting to use the battery for two and half days, the power was restored. I kept using the marine battery to power the ONT even after that. In total, the marine battery ran for three and half days. If we use the marine battery more conservatively, it would last for more than four days.

If the outage had been longer, I would have needed to charge it with the car battery or go some place where I can use my automotive battery charger.

Since this temporary placement of the extension cord was nuisance, I later placed an emergency power cable through the basement. In addition, I added a small inexpensive battery voltage monitor, which was $3.99 with free shipping but took a while to arrive from Hong Kong. Currently, I am charging the battery more or less monthly, using a car battery charger. It would be better if I had a float charger, e.g., Battery Tender Junior or Xciter 5-Stage Charger/Maintainer, but I have not yet purchased any.

Conclusion: With the use of an extra marine/automotive battery, we could power the ONT and charge electronic devices more conveniently.