[asethi]

Originally Posted by JithinR

I live in an Apartment in Bengaluru which has pretty good backup capabilities. Our Backup kicks in a minute or so after the power cuts out and carries us through most of the day when required.

However, until the COVID-19 lockdown made me WFH, I never realized how many times in a day the power cuts out. I am not sure why the BESCOM guys have not tried to reduced the frequency of Power cuts (if they did try to do something then they seemed to have failed) even when they know that many people are working from home these days.

With Apartments that have Backups, the need for a full fledged UPS does not arise. However, it is becoming increasingly annoying when the power cuts out during a conference call with my team mates and my router has to restart with the backup power. The few seconds that this takes makes my VPN application scramble to make another connection and then the connection in Microsoft Teams/Skype/Web-ex has to be re-established.

I was in similar situation bro, explored many options but none made only for router. Though DIY was not an option for me but I stumbled upon Resonate company that was promoting its WiFi router in my apartment complex, and finally I bought Resonate UPS for WiFi Router and it works very well. It’s very compact and doesn’t need much space. It’s a Bangalore based company & I got it from Flipkart.

[skoda0505]

In my case, the router and the modem are two separate devices so buying two Resonate UPS devices is turning out as an expensive option. One single Resonate UPS cannot power both devices at the same time because each one has a 1.5A power rating which exceeds the capacity mentioned in the Resonate-UPS specs.

Thinking more about the power bank option, what about using a Desktop USB charger with multiple ports ? For example, I have the following device at home:

https://www.amazon.in/gp/product/B06...?ie=UTF8&psc=1

Can I simply buy two USB to DC Power Cables (just like someone else suggested about https://www.amazon.in/xcluma-Power-A...EJK140EQ1Y6Z9F), and connect the router and modem through my Desktop charger?

This is similar to the powerbank technique except for the fact that it may be safer to keep the Desktop charger always ON as compared to a powerbank.

Please suggest.

[vigneshnr]

Originally Posted by JithinR

Creating this thread to get some advice on how to create an UPS for a router.

Finally, I am not sure how much I have missed in this setup. If there is something else that I need to take a look at then I am all ears!

Hi

I had been in this situation few years ago and started looking for products and DIY solutions. But finally went with UPS. And I would say I am happy about the decision - even after 4 years.

If uninterrupted connectivity is important, then I suggest to go with reliable proven solution. Especially when it comes to work situations or payments, I would prefer peace of mind

DIY may sometimes get frustrating. Though it might give huge personal satisfaction but it may fail for no reason despite your efforts.

I tried this powerbank + DC converter cable etc. But was never successful. Then after some reading, I understood that the powerbank has to be capable of "pass through" current and none of the product specs mention that clearly.

So, my recommendation would be UPS. I have been using APC product - And I have connected a Light, Desktop computer, Wifi modem in it. Works like a charm for more than 4 years. Standy is good 30 mins. If I use only the modem, then it has run upto 40-50 mins. I have not tested the full potential yet as I have apartment backup.


https://www.amazon.in/APC-BX600C-600VA-230V-Back/dp/B016XVRKZM/ref=sr_1_1_sspa?dchild=1&keywords=apc+ups&qid=1591 616212&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzNDE1T FpZRzJKTkREJmVuY3J5cHRlZElkPUEwNTU1NzAyVDdJM1VIQjd KRE04JmVuY3J5cHRlZEFkSWQ9QTA0OTk2OTRBOTlGM1pFTlNRR DYmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJ lY3QmZG9Ob3RMb2dDbGljaz10cnVl

[sidzz]

My apartment has 100% power backup, but there is a 5-10secs switching time. This used to be frustating while WFH or while watching TV.

I have been using the Resonate router UPS for more than 2 years now. Complete peace of mind.

I also ended up buying a Luminous UPS and connected the TV, STB, android box and speakers to it.

Both are good investments as far as my setup is concerned.

[Sutripta]

Originally Posted by JithinR

Creating this thread to get some advice on how to create an UPS for a router.
...
Finally, I am not sure how much I have missed in this setup. If there is something else that I need to take a look at then I am all ears!

How hands-on are you? Visually looking like a kludge acceptable to you?

Sutripta

[JithinR]

Sorry for not responding earlier (I think sitting in the apartment for months is pushing me into a depressive mood).

Originally Posted by Thermodynamics

Thanks for the DIY, timing is so right. Would appreciate if you can show your DIY setup in pictures.

The timing is so right when the only product in market is not available (Resonate went out of stock in no time).

I watched these videos when I was trying to make a jugaad using a power bank but stopped because of risk associated with overcharging. What surprises me is the router makers never had a product with built in power backup. That would be the most ideal thing.

May be they are banking on projections when 5G connectivity comes up, Sim card based wifi routers with Lithium ion back up would eventually take over conventional opticfibre modem/router combination.

Sorry if the title or some part of my Initial post was misleading. I was actually looking for some help on how to get this done.

I am not technically competent enough to attempt this. Since there seemed to be multiple guides online, I was thinking of giving it a shot (especially since most UPS for routers seem to be out of stock like you said).

I was able to spend some time researching this during the weekend and I have come to understand that this is not exactly an easy DIY project (once you start taking safety into consideration).

Most videos/blog posts that you see on this topic are from our fellow Indians and they don't really seem to be concerned with safety (most of them just strip the wires and join them with tape, no thought into how to charge Li-Ion cells safely etc.).

If I get ahead in implementing this then I will post a proper update here.

Originally Posted by PrashantPahwa

I dug out my old pc ups from my college days and got the battery changed for 700 rs. It's big and heavy but that's the best I could do because resonate ups is unavailable online since 2 months.
That is still the cheapest and more versatile solution as it has multiple ports.

Yep, its lucky that you have the old UPS lying around. I am not sure why but all the UPS designed for routers seem to have gone out of stock online.

Originally Posted by whitewing

Option 1:

The relay option suggested by @srini1785 seem promising and very cost effective, just needs a relay an some splicing of wires, however, it still means that the battery lifecycle has to be managed i.e monitor/recharge the battery regularly. But given the use case of just bridging a short (minute or two down time of the wall power) outage, may not be such a hassle.


Option 2: Buy a low power UPS board+battery overcharge protection+18650 battery
https://www.amazon.in/CentIoT-DD05CVSA-Charger-Discharger-Converter/dp/B078R8GYGY/
The cost would be comparable to a commercial option.

Option 3: Purchase off the shelf https://www.amazon.in/dp/B07S6NP7L5/, again the reviews are mixed.

Thank you sir for providing your insight into this.

Option 1:

I was looking into using relays to switch the power supply from the DC adapter to a battery powered backup but stopped short once I saw a few posts online that described how the router sometimes reset when the mains supply cut out and the switching voltage of the relay was too low. This caused the router to not get enough power and ultimately switch off.

Apparently, the same issue doesn't happen when the power comes back on. I am still trying to wrap my head around it.

I am trying to understand if a diode circuit or something based on Solid state relays will work here.

Originally Posted by bhp_maniac

I was in the same dilemma few months back and ended up buying something called "cuzor" router backup from Amazon.

Thanks for the recommendation. Unfortunately, just like all the others even this router model was Out of stock last I checked for it online.

Originally Posted by asethi

I was in similar situation bro, explored many options but none made only for router. ... and finally I bought Resonate UPS for WiFi Router and it works very well. It’s very compact and doesn’t need much space.

Thanks for letting me know about this bro. It seem's quite a few members here have this model. If this one ever comes back in stock then I will take a look at it for sure.

Originally Posted by skoda0505

...buying two Resonate UPS devices is turning out as an expensive option. One single Resonate UPS cannot power both devices at the same time because each one has a 1.5A power rating....

Thinking more about the power bank option, what about using a Desktop USB charger with multiple ports ? For example, I have the following device at home:

https://www.amazon.in/gp/product/B06...?ie=UTF8&psc=1

Can I simply buy two USB to DC Power Cables (just like someone else suggested about https://www.amazon.in/xcluma-Power-A...EJK140EQ1Y6Z9F), and connect the router and modem through my Desktop charger?

This is similar to the powerbank technique except for the fact that it may be safer to keep the Desktop charger always ON as compared to a powerbank.

Please suggest.

Even my router needs 12V and 1.5A. I didn't realize that Resonate one might not meet the power requirements. I will have to check up on it.

As for your Desktop charger approach, are you sure this can be used as an UPS? I am asking this because it just seems to be a version of an extension board but with USB's outlets and meant to sit on your desktop table.

I am not sure how this would act as a UPS since it doesn't seem to have a backup power source (that would continue supplying power once the mains supply cut out).

Originally Posted by vigneshnr

Hi
So, my recommendation would be UPS. I have been using APC product - And I have connected a Light, Desktop computer, Wifi modem in it. Works like a charm for more than 4 years. Standy is good 30 mins. If I use only the modem, then it has run upto 40-50 mins.

Thanks for the recommendation. I have started checking APC UPS systems but I don't think I would able to purchase this for now.

I am thinking of getting myself a desktop gaming setup in the coming few months (the lockdown has got me back into gaming after a hiatus of 6 years). At that time, I will need a UPS system for sure and it would probably have to be a pretty robust one. But for now, if I could get a system that works with the router that would be great. No use, getting an expensive UPS system and then using it just for my router (my apartment doesn't have TVs, Home theater setups or even a Desktop as of now).

Originally Posted by sidzz

My apartment has 100% power backup, but there is a 5-10secs switching time. This used to be frustating while WFH or while watching TV.

Agreed, that short switching time leads to a lot of frustration especially if you are in the middle of a conference call.

Thanks for the recommendations on the UPS systems.

Originally Posted by Sutripta

How hands-on are you? Visually looking like a kludge acceptable to you?

Sutripta

I am not really that hands on. This will be the first electrical project that I tried which is not related to something on my bike.

I did DIY a setup for my RTR 200 using a Maruti Omni fusebox, a mechanical relay(signal from the rear number plate light) to support my aux lamps, mobile charger, GPS/EDGE Bike tracker. I tried to place an emphasis on safety (which is why I didn't get the thing done from JC road) and used fuses, water proof connectors, soldered joints, heat shrink tubing etc.

A sleek appearance is not something I am really concerned about for now. Besides, if the whole setup works then perhaps I will just chuck it into a plastic enclosure with sufficient ventilation.

If you have a setup in mind then please let me know.

[Sutripta]

Originally Posted by JithinR

If you have a setup in mind then please let me know.

Assuming that the router input is 12V DC.

First do a bit of experimentation - whether a charged 12V Lead Acid* motorcycle battery can run the router, and for how long. If you have a multimeter, check at what voltage the router does not work anymore. (Assuming you dont have access to a variable power supply. There will be howls of protest about the deep discharge of the battery. Ignore it for the time being).

Then check out the open circuit and on load voltage of the power brick.

Let us know the values obtained.

Connect the battery in parallel with the output of the power brick, +ve to +ve, -ve to -ve, isolated using two# >2A Shottky doides. This will work, but the battery will not be charged. For that you have a number of options - a separate small battery charger (trickle), or a resistance across the diode which isolates the battery. Value to be chosen based on values obtained earlier.

Ideal - absolutely not. Lots of lacunae. But in true Indian juggad fashion, will get your job done.

* There is a reason for choosing a Lead Acid battery over other chemistries.
# If the brick is essentially a transformer rectifier setup, wont need the second diode.

Sutripta

[asethi]

Originally Posted by JithinR

Thanks for letting me know about this bro. It seem's quite a few members here have this model. If this one ever comes back in stock then I will take a look at it for sure.

Even my router needs 12V and 1.5A. I didn't realize that Resonate one might not meet the power requirements. I will have to check up on it.

I've the Resonate's local distributor number in case you need, the price is same online & offline.

And they have different models as per your V/A requirement, mine e.g. is 12V/2A, same model will work for 12V/1.5A. Check this out for your reference:

[cooljais]

Hi all,

Looking at all the queries regarding UPS for a router, I would like to explain a little project I took up during lock-down. After looking for some options, I decided to build the UPS for my router.

My router requires 12V 1A input DC. SO I have used 3 Li-Ion batteries to supply the required current.


Tools used:


1. Soldering iron
2. Multi-meter
3. Wires
4. Wire stripper
5. Soldering wire, flux

Raw materials used:


1. 3S BMS board – Output 12 V up to 15 A. Board regulates automatically. (https://robu.in/product/3s-15a-18650...tection-board/ )
2. 3 X 18650 2500mAH batteries (https://calcuttaelectronics.com/prod...ofer-2500-mah/)
3. 2 X 18650 battery holder (https://robu.in/product/18650-3x1-ba...r-holder-5pcs/)
4. 5.5mm Male jack (https://robu.in/product/male-female-...g-cctv-camera/)
5. 5.5mm Female Jack

Build

1. Connect the 3 batteries in Series.
   
   
   As shown below. Also note the terminal numbers. These will come handy when connecting to the BMS board:
   
   i.e.
   
   
   
   
2. The BMS board also has the same marking as the image above. Connect the respective points via separate wires to the batteries.
   
   
   
   P+ : DC input/output positive
   P- : DC input/output negative
   
   The output and Input terminals are same in the BMS board. When the input voltage is coming from the adapter, the batteries are charged. As soon as the power goes, adapter switches off, batteries start the backup via the same port. So no separate circuit required.
   
   
   
3. After connecting the batteries to the circuit as per the labels, it looks as follows. Checking for output voltage via the multi-meter. It is showing 11.19 Volts but it is enough to power the router.
   
   
   Connect the 5.5 MM male/female jacks to the P+/P- ports on the circuit board. The female jack will be used for input via the existing router adapter.
   
   The male jack will plug in to the router.
   
   
4. Packed everything in the box available now. Make sure to make vent slots so as for the heat to dissipate.
   
   
   
   
   
5. UPS powering the router.
   Video:

   https://youtu.be/jAS5VxapHMQ

Note: I’m using my router’s existing adapter for input power to the UPS.

[Sutripta]

Originally Posted by cooljais

1. 3S BMS board – Output 12 V up to 15 A. Board regulates automatically. (https://robu.in/product/3s-15a-18650...tection-board/ )

Hi,
This seems to be a Li ion charge management module, essentially a Li ion battery charger minus the power source, rather than a three port module. The site does not have much by way of information. Could you pls. give more information on this BMS.

Sutripta

[cooljais]

Originally Posted by Sutripta

Hi,
This seems to be a Li ion charge management module, essentially a Li ion battery charger minus the power source, rather than a three port module. The site does not have much by way of information. Could you pls. give more information on this BMS.

Sutripta

Hi Sutripta,

As you correctly mentioned, this is a Li-Ion charger module. However, that is one of the functions. The board also acts a Battery discharge module(for battery backup). The board regulates the charging voltage to each cell. The connections that I specified, help the board monitor individual cells. So if one cell is charged more that the other, the board takes care not to overcharge it.

The output voltage is 12V(11.19) as you can see from the screenshot. I tried with the DC-DC converter as well, but it did not make sense as my board was already giving out 12V. DC-DC converter will be required where you are having the board output voltage less than the required one (eg. 2S BMS board. It gives about 8V output).

Do let me know if you need any other info. Also, I have been using this for almost a month now. As per my research over internet, i found that these boards are pretty safe. However, as you mentioned, we do need to be extra careful when working with Li-Ion batteries. Make sure the Positive terminal does not touch the cell body while working.

[fordday]

Originally Posted by cooljais

Do let me know if you need any other info.

How did you do soldering into the base / terminal of the batteries? Is it safe to put hot solder in the battery ends? Does it stick? Earlier I tried the same with a set of Panasonic NiMH batteries. The solder used to come off even with a mild touch.

Anyway many thanks for the solution. Will definitely be ordering the items to build myself.

I also need an emergency LED light which will come on when power goes off. Backup need not be more than 5 mins. I think 1W power rating for LEDs will be enough. Please put in your ideas.

[Sutripta]

Originally Posted by cooljais

As you correctly mentioned, this is a Li-Ion charger module. However, that is one of the functions. The board also acts a Battery discharge module(for battery backup).

Would really like the application note (or similar) for this board.
From what I can make out, it is a two port board. One power input (the power brick), one output (the battery). How does the battery backup work?

The board regulates the charging voltage to each cell. The connections that I specified, help the board monitor individual cells. So if one cell is charged more that the other, the board takes care not to overcharge it.

Aren't the cells connected in series?

Sutripta

[cooljais]

Originally Posted by fordday

How did you do soldering into the base / terminal of the batteries? Is it safe to put hot solder in the battery ends? Does it stick? Earlier I tried the same with a set of Panasonic NiMH batteries. The solder used to come off even with a mild touch.

Soldering on to the Li-Ion need to be done carefully. Normally there is a nickel plate used in coordination with spot welding. Since i did not have access to this, i found that you need to scratch the ends with something like a blade. Make it rough. But please make sure, when doing it on the positive end, you mistakenly don't short the positive port to cell body.

The solder sticks good enough. Once soldering is done, and setup in the box, it works out fine.

For emergency LED, I'm sorry but have not worked on something similar. But will definitely check this out and let you know.

Originally Posted by Sutripta

Would really like the application note (or similar) for this board.
From what I can make out, it is a two port board. One power input (the power brick), one output (the battery). How does the battery backup work?

I'm sorry, but do not have any note for the board. Unfortunately, was unable to find one. But if we reach out to the site, they might have it. But this is a generic board so I doubt they might be able to provide the same.

The port for Input and output(to router) are same. Till the time power is coming from the adapter, it directly goes to the router. As soon as the power goes out, the board switches the output via batteries. The backup i tested till now was about 10 minutes. However, i need it only for a minute or so till the time the power backup kicks in.

The batteries are connected in series. However, if you see the points B1 and B2, they are connected to positives of 2 batteries. And the third battery positive is connected to B+. This helps the board regulate supply to each cell individually.

[JithinR]

Originally Posted by cooljais

Hi all,

Looking at all the queries regarding UPS for a router, I would like to explain a little project I took up during lock-down. After looking for some options, I decided to build the UPS for my router.

My router requires 12V 1A input DC. SO I have used 3 Li-Ion batteries to supply the required current.

Note: I’m using my router’s existing adapter for input power to the UPS.

Kudos to you sir! You actually did it (while I have been dithering like an idiot on this for the last three weeks).

Thanks for providing links to the components too. Could you please let us know how was the delivery time for these sites (robu.in and the other one)? That was one of my points of concern since they might not have a robust delivery setup like Amazon/Flipkart.

My router though is a 12V and 1.5A router. I was advised by other members on the forum to go for a setup without the DC converter too.

If I follow that route then I will need to place the three batteries in series like you did. However, I do have a few concerns here. If you (and any one else) could please provide your thoughts that would be great:

1. For Li-Ion, as far as i know, the nominal voltage comes out to be 3.7V. So three of them in series will give out just 11.1V. Also, as far as i know these BMS boards have an Over discharge voltage range : 2.3-3.0v ± 0.05v (at least this one does : https://www.dnatechindia.com/3S-Li-B...search=Lithium). Assuming the worst case won't we be under-volting the router by a significant margin? My limited understanding is that while over-volting is fine to an extent under-volting is strict no-no.
2. While the batteries are fully charged (Over-voltage range : 4.25-4.35v ± 0.05v for the same board) won't the output voltage cross 13V. I suck at electronics so I am not sure but at this point won't the higher voltage drive more than 1A into your router?

I was thinking of going with a 2 Li-Ion batteries in series because of this (I am just scared of blowing something up). If I use a switching circuit (to regulate when the battery supplies power to the router) then I would be able to charge the router and re-charge the batteries through a 2S BMS board.

The output of the 2S BMS board can be connected to a boost converter. This is another point of concern for me as far as the 3 Li-Ion cells in series is concerned. In their fully charged state (outputting over 12V) I would have to use a boost/buck converter that seems to be more expensive. Is this correct?

At this point, this is the circuit diagram I have (it's in the attachments...copied from another forum and modified for the components I have in mind). Sorry about not having the circuit simulation link (I am not a paid member).

For now I was thinking of using a p channel MOSFET with the gate tied to the ground through a pull down resistor. The battery is connected to the output through the MOSFET and will supply only once the Input DC power goes off.

I have kept a decoupling capacitor at both the output and input (I am not sure if this one is needed) to smooth out any voltage variations.

My calculations are as under (they are at an amateur level right now):

1. Max Power Draw for my router: 12V * 1.5A = 18W
2. Efficiency of the DC boost converter (94%) : 19.4W
3. Current drawn from Li-Ion Cells: 19.14W/7.2V = 2.65A
4. Battery Capacity required (Assuming a 5 min runtime): 2.65A * 5min/60 = 2.20mAh

With two Samsung Li-Ion cells I am hopeful of meeting the capacity requirement (Apparently most Li-Ion cells don't have the actual capacity shown)

https://www.youtube.com/watch?v=8uBcywBUTkw