Verizon ONT (Fiber) Modern Battery Backup for Internet! Hours of Battery Life

I live in a very old apartment that was built before electrical outlets were standard. When outlets were finally added our entire apartment was wired with a single 20A breaker... As a result of this, the breaker trips quite often, and while I have my computer and networking equipment on a UPS, the Verizon ONT is in a separate room.

I originally planned on adding a second UPS next to the ONT, but I wondered if I could do it for less then $50, while still having a decent amount of runtime.

I should note that this all hinged on a guide by mousehunt, who posted the original "I-211M-L ONT: Enable Data While on Battery Power" instructable, allowing this to be a solvable problem in the first place.

Credit to mousehunt's instructable here: https://www.instructables.com/I-211M-L-ONT-Enable-Data-While-on-Battery-Power/

I had ALSO originally planned on using the DC barrel jack on the side of the ONT's power supply, but that is either broken on my unit, or has been disabled/disconnected internally, so investigating I went.

TOOLS:

Flat head screwdriver

Scissors or side-cutters

Wire-strippers or just use the sidecutters

Tweezers or needle nose pliers.

A multimeter is suggested, but not needed.

PARTS:

• A small piece of Tin foil.
• 5.08mm Pitch terminal blocks, (also known as phoenix connectors) 2 or 3 Pin, I bought this set on amazon. You do not need the whole set, I had other uses for the different sizes: https://www.amazon.com/dp/B09LXYMDGC?psc=1&ref=ppx_yo2ov_dt_b_product_details
• If you want just the 3 pin connector, you can buy it here: https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/282807-3/1150111
• 12V DC battery, Commonly found to as an LED battery pack. I bought this one: https://www.amazon.com/TalentCell-Rechargeable-Amplifier-Multi-led-Indicator/dp/B00MHNQIR2/
• An Outlet splitter or short extension cord with multiple outputs. To connect the ONT power supply and the battery charger at the same time.

On the power supply, you most likely have a small shroud on the bottom that covers the power output cable, and a small green connector. You can remove the shroud by pushing up and sliding the cover off. This should reveal the DC connector that goes from the power supply to the UPS, and the green 3 pin terminal block connector. All you need to do is make sure the pinout matches and you can follow this exactly as written.

The battery I have linked under the supplies section includes a DC barrel splitter. One of these ends connects to the 12v battery, the other output is designed to go into an LED controller, but we don't want that connector. Use the scissors or sidecutters to remove the second male barrel jack and expose the two wires inside.

Strip a small amount off of each wire and attach the stripped ends to the terminal block.

If using a 3 pin connector, put the positive side (red) in the left side of the connector (With it oriented as shown in the image), and the Negative (white or black) in the middle. Ensure the clips are facing up, some terminal blocks have the screws on the opposite side, and may put 12v to the data (ON BAT) connector, which I left blank.

This step is pulled directly from mousetrap's guide. On the ONT side of the connector (NOT the Power supply side), with the indent oriented up, take a small piece of tin foil and wedge it in between The top right 2 pins (Pin 8 and 9) and middle row of pins. Only pin 4 appears to be used in the middle row, I tested every pin with a multimeter.

BE SURE not to short pin 1 or 2 to this group, as they carry 12v to your ONT and this will trip the power supply's fuse.

Connect the ONT power supply and battery adapter to the AC outlet splitter or extension cord. Connect the battery adapter to the barrel jack splitter.

I suggest connecting the ONT and power supply first to ensure your tin foil is not shorting 12v to ground. If you hear any pops or smell burning, unplug it immediately.

Plug the 12v adapter into the barrel jack splitter, and connect the male barrel jack to the battery. Turn the battery on.

Connect the terminal block to the ONT's Power supply. If you did everything correctly, you should see the ONT reboot. It may do this more then once. Watch it closely and keep a hand on the power supply, battery, and ONT to ensure they do not start heating up rapidly.

If done correctly, you should now be able to unplug the entire assembly and the ONT will stay powered on. If the whole device powers off, ensure you connected the battery properly.

Note: The battery adapter may flash green and red, this is normal as the ONT will draw a tiny amount of current from it, making the battery adapter (charger) think it needs to charge the battery. This is normal and has not caused an issue for the month I've had this system running.

Thanks for reading!

-Brink