Handmade UPS. I have used three 10,000mAh batteries. I am using a BMS for battery protection. And I am using the original RC BD V2.6 for power supply to the router and ONU. I will keep this for my own use. If anyone wants, you can order one to be made. If you want to buy the parts yourself, I can build it for you, you just need to pay for my labor. I will let you know how many hours of backup it provides after using it. (I got 12 hours of backup). Thanks everyone.