\# DIY Router UPS Build Specification

\# Project by: Suman

\# Build Cost: Around ₹2000

\# Back-up Time: Giving approximately 4 hours of backup time

I built this Router UPS 4 months ago when I switched from AirFiber to broadband. I was facing frequent short power cuts, and since I live in a village, power outages during rainy days can sometimes last for many hours.

Initially, I planned to buy a commercial Router UPS under ₹2,000, but after reading many reviews, I noticed several common complaints such as insufficient output current causing reduced router performance, switching delays, poor backup time, and units failing within a few months.

As I have loved electronics since childhood, I decided to build a high-quality and reliable Router UPS myself instead of purchasing a commercial one.

I completed this project about 4 months ago, and since then, it has been running 24/7 smoothly., and since I occasionally see DIY Router UPS builds on Reddit, I thought I would share the details of my Router UPS as well.

Components Used:-

1.) ₹108 : 4x7x2 inch PVC Junction Box

2.) ₹8 : SPST 6A Battery On/Off Switch

3.) ₹250 : XL4016E1 300W CC/CV Converter

4.) ₹15 : SS54 5A Diode

5.) ₹150 : 150W Boost Converter

6.) ₹40 : 2200uF Rubicon YXG Series Low ESR Capacitor + 2 Ceramic SMD Capacitors

7.) ₹20 : Triple Fuse, One Fuse With Holder, Other In Heat Shrink Tube

8.) ₹6 : 4 Pcs 3mm LEDs (Blue, Red, Green, Orange)

9.) ₹510 : 3 Pcs DMEGC 2900mAh 3C Rated 18650 Lithium-Ion Cells

10.) ₹25 : 3S Battery Holder

11.) ₹20 : 2 Pcs DC Female Jack

12.) ₹20 : 2 Pcs DC Male DC Connector

13.) ₹250 : XHM609 Low Voltage Cutoff Module

14.) ₹70 : 3S 10A BMS

15.) ₹10 : 1000uF 16V Capacitor For Inrush Protection 

16.) ₹70 : 0.5mm Wire

17.) ₹150 (2nd Hand Costed Me ₹150) : Original 90W Asus Laptop Adapter

18.) ₹60 : SCR Crowbar Protection Circuit (BT151RT,5W 13v Zener,1k Resistor, 0.1uf Cap, Zero PCB)

19.) ₹50 : Low Battery Warning Indicator (LM358 With Holder, 2x10k Pot, Orange LED With 10k Resistor)

20.) + ₹100 : Extra Wiring & Tape (11 Pcs Zip Ties,3M Double Sided Tape,Insulation Tape,Hot Glue, Stickers)

\[SYSTEM CALIBRATION\]

\- XL4016 Buck Converter: Set to 12.05V / 1.50A 

  (Logic: Powers the Router + Charges Battery to 80% limit for longevity)

\- 150W Boost Converter: Set to 12.05V (Perfect for the Router)

\- When AC power goes off, the battery takes over instantly.

\[PERFORMANCE NOTES\]

\- Real-world Backup: Approximately 4 Hours

\- Thermals: Runs very cool due to high component overhead (100W+ capacity for a 6-8W average load).

Highlighted Features:-

1.) Sturdy Build:- 4x7x2 inch PVC Junction Box used for a sturdy, heavy-duty build.

2.) Modular Design:- Batteries, Buck Converter, Boost Converter, XHM609 etc are easily replaceable. All modules are screw-mounted on the enclosure.

3.) Overrated Components Used:- The 150W Boost Converter powers a router load below 10W. The XL4016 is capable of 300W but operates at only about 7-18W, resulting in low heat and high efficiency.

4.) High Quality Batteries:- 3x DMEGC Branded 2900mAh 3C-rated cells used in series with a 10A BMS providing overcharge, over-discharge, overload & short-circuit protection.

5.) Battery Life Protection (80-20 Rule):- Charging voltage limited to 12.0V (\~80%) and cutoff set to 9.9V (\~20%) & Hysteresis 11.2v through XHM609 for improved battery longevity.

6.) Router Side & UPS Protection Features:- 2A input fuse with SS54 diode for reverse polarity and current backflow protection. Triple fuses are used: a 3A battery line fuse, a 2A input fuse, and a 2A output fuse. If anything ever goes wrong and the UPS malfunctions, causing an overvoltage condition, an SCR Crowbar Protection Circuit is present. Under normal operation it remains inactive at the safe router voltage (12V). If the output voltage rises above 13.2V, the SCR triggers and shorts the output, blowing the output fuse to protect the router. The XHM609 provides a clean cutoff and a 2-second startup delay. A 1000uF capacitor after the BMS prevents nuisance tripping caused by inrush current. The UPS also provides true zero switching delay.

7.) Wide Input Voltage Range:- Supports 14V-30V DC adapters.

8.) Pure Clean & Stable Output:- The router always receives a stable 12.05V output. Additional filtering is provided by a 2200uF Rubicon YXG Series Low ESR capacitor along with 1uF & 0.1uF ceramic capacitors to reduce high-frequency noise.

9.) Battery On/Off Switch:- Dedicated battery isolation switch provided.

10.) Indicator Lights:-

Green LED = Mains Power

Red LED = UPS Mode

Blue LED = Output Active

Yellow LED = Low Battery Warning (<10.5V - Below 20%)

11.) Adapter Details:-

90W Asus Laptop Adapter used for powering the system. The adapter is intentionally overrated for improved reliability and longevity.

I think my DIY Router UPS can beat any commercial variant in this price range in terms of value and quality. The only downside is that the build took several days, as I gradually improved it and fixed various flaws along the way.

~~I know some cost-cutting could have been done~~, but my main focus was on quality, reliability, and long-term durability rather than minimizing cost.

**Sorry for the long post, and have a nice day! :)**

**And yes, I know the inside of the UPS looks like a time bomb 💣😜, but from the outside, it actually looks pretty good.**

My High Quality Router UPS Built Under ₹2000/-