DIY - 12V Mini UPS

[@alois17]

Hi Sorin. Transforming 12 V -> 220 V in a UPS and back 220 V -> 12 V in a router's power supply was always not a good idea to me. I always wanted to get (build) a pure 12 V device. This your video inspired me to do that. Thank you so much for this! Please let me share some of my observations with other people working on such devices like me. 1) You can remove the step up converter from your schematic for most cases. The most of routers, network switches and others have buck converters inside. Usually they reduce voltage to 3.3 V to power the controller. This means you can power devices by even 5 V. Just try. You will be surprised. It looks like manufacturers choose power supplies having just economical reasons while devices can eat from 5 V to even 18 V. 2) Do not worry about back current into the power supply. It is usually less than 2 mA for most power supplies and is safe for them. Thank you again for your videos.

[@kongmeurn38]

Tested and approved as correct!

[@namangupta86]

You must add a diode to the laptop plug from where the adapter is connected to prevent the electricity from going back towards the charger. Not only would the backup of UPS will increase but it would be safer this way.

[@husseinbazzy8294]

my thoughts EXACTLY

[@AtlantaTerry]

What should the diode rating be?

[@mota1maji]

@@AtlantaTerry anything would do a 1n4007 has a rating of about 700v.

[@whitepawrolls]

While your at it could add an inline fuse that would blow before the ones on the battery did as those are harder to get to.

[@thanoswasright626]

Sorry where would the diode be connected?

[@ggppdk]

Really, a quality video, with nice humor. I like that you give instructions for a safer and cleaner result. Plus you give explanations of what you are doing and why. Regardless of building or buying such a mini UPS, the learning process and understanding of the details are valuable for other projects plus as a general knowledge too. Thanks.

[@viralindia8951]

It's not working for me. Before connecting to boost converter, bms output voltage is 11.68 v but as soon as I connect it to boost converter, voltage drops to 0.67 V. And so can't step up the output for 12v. But when I connect boost converter directly to battery output, it works, which is not advisable !!! Please help with this

[@AbdulMominCosTheta]

@@viralindia8951 if your bms output is 11.6v then you can easily use it as 12v. There's no need to use a boost converter. Also, there is a limit to the input voltage for the boost converter. You should check the specification.

[@ampedandvolted]

I like this design because you take extra care by A. putting the fuses directly on the battery as the BMS can fail and B. adding a capacitor on the output to smooth out the flow. Very nice. I'm going to make this, but with 3S.

[@computerman8424]

this is a very practical project and anyone who suffers from random power outages should do this. Very simple and straight forward! Great video as always :D

[@pehristov]

If you want better efficiency, remove the step up converter and add one more battery in series. The router should be able to operate from about 9V up to 14V. Li-ion batteries work 3.5V - 4.2V, which gives you 10.5V - 12.6V power supply.

[@AbidAli-bo8sv]

No, my router works 11v-18v. Although rated at 12v. It doesn't work anything less than 11v. So step up is mandatory. Schottky diodes are also required.

[@zeran74]

Those would likely sell well on amazon many people would love them.

[@haydenc2742]

Nice build! Best part is it will protect the router in those short power blips that usually reset everything. Great job!

[@AtlantaTerry]

Yes. I need a small UPS for my Raspberry Pi system.

[@STNG17-]

I also made one for my router but with 3S config. It'll be more practical to do so because you don't have to change the 12V adapter. Good video sir!

[@ChillarPunter]

What step up transformer did you use?

[@jithinramesh3022]

Can you please help by giving a list of the components you use? I am looking into building one but don't know where to get the components online.

[@phylaxxx]

@@jithinramesh3022 The two main places that people source parts for electronics projects are AliExpress and Banggood. They're both Chinese websites which allow you to essentially get the parts for the cheapest price and they usually have global free shipping. I would personally recommend Banggood because I usually get my items within a week and a half when ordering from there vs AliExpress which can take weeks but usually not over a month. I live in New Zealand which means components ordered from these sites get here a bit faster then other parts of the world. As for your question regarding the components that Aji used I might recommend trying a premade board that essentially does everything the BMS in the video does in a single package. Something like this: www.banggood.com/18650-Lithium-Battery-Boost-Module-12V-Charging-UPS-Uninterrupted-Protection-Integrated-Board-With-C-p-1280431.html?rmmds=search&cur_warehouse=CN

[@volodumurkalunyak4651]

@@ChillarPunter with 3S battery and 12V router no step up or step down converters are needed. Router will still work, even when supplied with 9V (3S battery at 1% charge)

[@usamamansoor]

For 3s, the Charging voltage should be greater than 12.6. How did you get this voltage with 12V adapter without using step up convertor?

[@idea-shack]

Very nice, I was designing exactly such a thing for my rooter today and there pops up your video in my recommendations! In my design, I also added a constant current, constant voltage buck converter and set the current limit recommended on the data sheet of the 18650.

[@Sorin_DIY]

hi. if you used a buck converter, then it means you have a bigger battery pack. but the current limit of the buck converter is for the converter output, not the converter input (the battery pack). the input current and output current of the converter differs, depending on the load, converter efficiency and battery pack. there is nothing wrong with it, just don't set a lower output current than your router needs.

[@idea-shack]

I have the battery pack charging FROM the buck converter output, that way when the battery is flat, it charges at constant current (1.65A for my cells... they're 3500mAh so ~0.5C charge) up until the preset voltage is reached for full charge, then it switches to constant voltage mode and then the current drops quickly down. I still use a boost converter on the battery pack to the UPS output to keep the voltage constant as the battery voltage drops. I then use a much higher voltage power supply (24V, ~1A, 25W) because its slightly cheaper and also I get better efficiency stepping down from higher voltages with the buck (>90%). The buck isn't strictly necessary and your design is elegant.

[@OverlandOne]

Very nice and useful build. You explained everything very clearly and also put a list of the required components in your video description. Very well done.

[@dleivam]

Brilliant.. I've lost a lot of work due power outages of few seconds, but that's enough for the router to restart and I have to wait until the router reconnects. I definitely try to do something similar as your mini ups. Thanks for the good idea.

[@adk_88]

8:00 you should also make a knot with the power cord inside the case, that way if you pull on the power cord, it wont pull the electronics out and damage the soldering points

[@sherrycambridge1531]

ok

[@whitepawrolls]

That or one of those crimping type strain reliefs that just snaps into the hole a lot of appliances use. If space is the issue as in that small case one of those snap in might take less room.

[@MagicGate814]

I like this build. There are many applications you can use this for, like emergency lighting when the power goes out

[@glauciogv5225]

Very nice video, congratulations ! ("Precision Sensor" for temperature was perfect ! )

[@zaidhussain5206]

Thank you Sorin for sharing this video, really informative , I have some notes regarding :1-You can use a battery holder for the 18650 you using in case you need to replace the batteries it will more easy rather than doing the soldering job again.2-You can use a protection schottky diode on the input side link SS54 so that the voltage can flow in one direction & not back to the charger in case of utility power outage 3-you can add a switch yo turn of the built in voltage meter to preserve some energy in case of long term power outages.4-what about low battery , should we get any indication when the battery is going low , it the UPS turn it self off in that case ?5-also what about short circuit protection on the output side ? Thank you.

[@Sorin_DIY]

hi. 1- yes you can use a battery holder, but I prefer to solder the cells. I test all the cells before I use them, so very rarely I had problems and need to replace cells. I prefer soldering the cells, because with battery holders there may be an imperfect contact in time between the cell and the holder, also the plastic enclosure needs to be bigger. 2- a diode will block the current from one direction, but it also has a small voltage drop. so the charging voltage will drop below 8V, which is not enough to charge the cells. the charger LED is using only a few mA, it doesn't make any difference in the 6 hours working time of the UPS. it remains like this for now. 3- the voltmeter display is using 17-20 mA, depending on how many LEDs are lit. so yes you can save a little energy by disconnecting it. you can add a capacitor and a microswitch to the voltmeter. when you press the microswitch for 1-2 sec, the capacitor is charged and the voltmeter will remain on for a few sec, enough to read the value. 4- the BMS has over discharge protection at around 2.9V per cell. you can check the UPS voltmeter, when the voltage decreases to under 6V, the cells are almost discharged and it will shortly turn off. I did this test in the video. 5- this step up converter doesn't have short circuit protection, so you can add another fuse on the positive output terminal. or you can use another (bigger) type of step up converter, with short circuit protection included.

[@ArifKamaruzaman]

Interested in your temperature measurement instrument. Very clean and nice looking project.

[@DigitalIP]

Nice vid. I recently started using TP4056 Chrg/Prot boards with a long 22 gauge silicone electrical wire to help charge solar lights with 18650's when sunlight isnt good enough. With how well it works it doesn't make sense why big solar lights aren't designed with this feature built in

[@Randellallen65]

Always informative, I learn something everytime I watch your videos...

[@rybeenali4371]

It is shame that KZbin algorithm does not recommend such good content

[@pip5461]

I like the precision temp sensor, also the cumbersome looking soldering iron... nice project to keep us occupied ... I think your cat looks as if it's been electrified, judging from the spiky fur... :)

[@madushankasrimal1106]

Hello Sorin, Thank you for this video and it was helpful for me to provide a solution to the unexpected power outage of my wifi router. All the best and appreciate you.!!

[@creativeworx47]

I love the "wearing protective goggles with smug face" part.. Funny

[@debasishbasak6953]

This is the first ever channel that I have intentionally subscribed. Liked it and much helpful.

[@demolishedman50]

Luv your projects and your humour.

[@zaidhussain5206]

Sure he has a sense of humour , I like it too.

[@paulbonion]

The precision sensor, "between hot/cold."

[@imperialrecker7111]

Video: How much safety you need? Sorin: YES

[@Shubz0p]

Too much protection than any oth product which is made officially 🤣😅😆

[@russgibson7376]

NIce! I just ordered a bunch of 18650's for another project, so that was great timing for me. Thanks!

[@richd.3270]

I was actually looking for something like this, a portable or mini UPS for use with the Raspberry Pi. Thanks for making this tutorial, Sorin. :)

[@SmithyScotland]

Those plastic bit in the case are called "stand offs". They "stand off" a pcb from the case. Normally used on pic's so the motherboard doesn't short against the case

[@Sorin_DIY]

thanks for clarifying this. I know what they are for, just didn't know how to call them in English.

[@raresvintea1]

Bravo omule! E ceva de munca si la ceea ce ai realizat cat si la clip, felicitari!

[@fredrickawinyo]

You have always inspired me to step out and try some of your projects. Thanks for the content. For the power flowing back to the adaptor, you could have a diode to prevent that, learnt that from a solar installation...

[@whatworkedforme]

I learned a lot with this YT video.. esp the BMS system and how it works. Great job. Thanks

[@jayo7799]

Great explanation! Thank you, very easy to understand the operation of 18650 cells on smaller scale. I'm trying something similar before going larger, these things actually are alittle scary and should be treated with caution. One thing I don't understand, does the bms monitor each individual cell ? Thanks great job and that was an important tip selecting good vs bad batteries from the start. 👍👍

[@Sorin_DIY]

hi. yes the BMS monitors the voltage of each cell, that's why it has a lead between the cells. it's the yellow wire in my schematic.

[@MB-cz1go]

Very good and respect to your Li Ion Information. Very good also for safety! You should use a metal case for absolutely safety

[@Newb1eYou_]

Sorin you're the best i think i can make this because i just ordered some parts thanks sorin

[@JAG9100]

just a tip, if you change the setting on the opus charger to "charge test" it will charge the cells up to 4.2, discharge them, giving you the discharge capacity, then charge them back up. making it easier and quicker to test them multiple times

[@Sorin_DIY]

I know. I forgot to film it.

[@ilyatulchinsky339]

Thanks for the video. Can you please advise what changes I would need to make if I want to use 12V power supply? Thanks for your answer.

[@baniakrulez]

with exactly same build you need one more step down DC to DC board to lower 12V from power supply to 8.5-8.4V to charge the whole mini UPS, all the rest stays the same.

[@ilyatulchinsky339]

@@baniakrulez Thanks. Will do.

[@GotaSir911]

I built a small ups with a 9v battery and boosted it upto 12v using the converter, I used it to power my stereo speaker but after a few minutes it resetted itself and when it came back up it worked perfectly. But it killed my device's original speakers, now I'm stuck in headphone mode. I didn't have 2 18650 cells so that's why I used a 9v battery. But I have another recharge ups. Thanks for the tutorial friend.

[@pierre5325]

Friend, Sorin, thanks for an excellent tutorial. (I have subscribed) I like that your presentation was well photographed. Everything you showed was easy to understand. (even a dummy such as myself) One suggestion, perhaps go a bit slower. Thanks so much, looking forward to more of your presentations.

[@ssingh6969]

Appreciate the compact circuit, I am also trying to make the same. But one query arises in my mind. That why we did not consider, reverse discharge protection diod in the supply side.

[@Sorin_DIY]

it will work, but you need a 9V charger to compensate for the diode forward voltage drop.

[@nilangarukshan8464]

@@Sorin_DIY Is it okay to use a 12V 0.5A charger and a 3S 10A BMS?

[@achalbhoir1359]

Hey , you forgotten 1 diode at input of BMS, that will help to reduce extra current drawn by charger LED during power fails

[@Sorin_DIY]

yes a diode will block the current in the reverse direction, but it also has a forward voltage drop of around 0.9V so the charging voltage will drop under 8V, which is not enough to charge the cells. the charger LED is using only a few mA, it doesn't make any difference in the 6 hours working time of the UPS.

[@AtlantaTerry]

"LED": Light Emitting DIODE. So why would you need a second diode?

[@freakynuell129]

@@AtlantaTerry simp

[@whitehoose]

I've modded this good original design, my fibre router was affected by the high frequency of the boost output. Instead of 2x 18650+boost I found it simpler to use a 3S 20A Li-ion Lithium Battery 18650 Charger PCB BMS. and a standard 3s battery holder. Mod the standard router power lead to tee in the BMS via a 5.5 power jack and fix to the back of a standard 3s 185650 holder (if you need more double up and use 2 cells in parallel x3). 3 cells just about makes a good enough 12v and not having to boost makes life much less complicated, you can use the router's standard psu with bee sting connector to feed the BMS. Because the BMS is teed across the feed and doesn't intercept it - switchover is still instant and bonus is the batteries smooth the PSU output without a capacitor - it means you can disconnect (borrow) the UPS to act as a powerbank without powering down the Router so with the BS on the back of a standard 3 cell 18650 carrier I think it's actually a smaller footprint with a more convenient switchless "always on" connection. Because you tee the UPS to the power feed there is no chance of an accidental break in service win win.

[@studiocreator2168]

Try for the next project a spot welding device solution for nickel strip .

[@rajeshruchandani]

Very nicely presented. Thank you for explaining so well. 😊👍

[@abcdelmo]

Oh. Thank God i found this on my feed.

[@josephwheeler1]

I love videos that give good instruction. That's the reason I've subscribed to you keep up the good work.

[@lnxpro]

Why not make it out of 3S for 12.6v fully charged and 9v fully discharged? Then you would not need the boost converter. Your fiber router would probably cut off around 10v or less than that.

[@Sorin_DIY]

I wanted to have a very stable 12V output. other people will probably make it for some other devices that may need a stable voltage. this is possible only with a dc converter. it will last longer with a step up converter, because it's using the entire battery capacity. and I wanted it to be small, with 3 cells it needs a bigger plastic enclosure.

[@anandsingh8987]

I have couple of questions: 1. Why capicitors and how do you determine the specification? 2. How are you handling the heat disscipitation from buck boost converter as with xl6009, and 8v to 12v with current 0.5 A, it generated good amount of heat.? 3. What is the total capacity and how long this product will support ie. 1 or 2 hours... Very well documented and good video.

[@Sorin_DIY]

hi. capacitors hold a small electrical charge. they are useful, for example, when you connect a big load, the supply voltage may decrease for a second. the capacitor charge will help to keep the voltage stable in that second. the bigger the capacitance, the higher the charge is. so for a bigger load you need a bigger capacitance. for voltage smoothing usually I use capacitors between 1000 - 6300uF, depending on the project. in this project, the step up converter IC only warms up a bit. it can handle up to 85 degrees C and I also added a small heatsink. but for higher current you need a bigger heatsink or a ventilated enclosure. more than that, my ONT is using maximum 270mA, so no problem with the heat. in these conditions it has an autonomy of around 6 hours.

[@matyaslukacs3021]

Te rog fa un video in care arati cum ai facut ampermetrul!!

[@George-sp1sr]

Este doar un volt/ampermetru pus intr-o carcasa. :)

[@greenones8754]

When I see you fit things the together as if made for each other I'm sure you could break the world record on "points scored on Tetris in 60s😂" ✌️

[@emersonsrandomvideos248]

Sorin, bro, are you russian? Its nice that this video of your's is in english. Congrats bro!!!

[@George-sp1sr]

No, he's Romanian.

[@emersonsrandomvideos248]

@@George-sp1sr Aaahhh i see...

[@luigisalvacion4536]

Today is a good day because sorin uploaded another informative diy video

[@techbarron7383]

I really love this channel.. verry imformative,and funny... ohhh,,,,!! it has ads now,,,,thats it sorin,,, 🙌

[@hycron1234]

Cool, might have to build one of these. I usually use a 10000mah powerbank, which can last around 7 hours running an adsl modem router with wireless.

[@DrZipZwan]

+1 for ur humour and the smug face 😂 (1:10) Why you did not use your previous DIY charger to test the batteries?? maybe because it do not have a screen showing capacity of batteries? So time to make a v.2.0!! , DIY Charger and Tester Capacity for 18650 bats. Look ZB2L3 Battery Capacity Tester, not a bad module 😉 And look for us a DIY spot welding machine please, most uses microWave transformer, but a bit hard for simple hobbist... maybe with capacitor?? you will figure something it out 😊

[@franzhankins1137]

High quality content right there it's rare to see those

[@twotone3070]

Oi! ... Who are you calling elderly? :)

[@AudioDogFlorin]

Tocmai ce am trecut si eu la fibra optica si am si o gramada de celule si bms-uri, deci am ce face in weeknd! Multam de idee si cum ar spune americanu' : keep up the good work !

[@informediatech-bruno5766]

my router has a built-in batery kkkk

[@Sorin_DIY]

that's nice

[@EmilePolka]

you can buy a cheap USB cable with barrel jack at the end, just make sure you buy the cable that can do a QC 3.0 handshake since you will be taking advantage of QC 3.0 12volt output. After that just buy a powerbank that supports QC 3.0 with 12v output, pretty much every QC3.0 compatible powerbank support it, after that daisy chain it with QC 3.0 usb charger and your good to go, a UPS for your ISP router, not to mention everything I told cost around 35-40USD for all of it.

[@bee1010]

Just build mine... I thought I burn out my BMS when I saw Sparks while soldering but it works thanks for your video.

[@giladit77]

Okay, so after checking again and again the problem was with the fuses. Without the fuses everything is fine. Interesting even though the fuses are meant for protection. Thank you for your help you are the best 😉

[@prakharvj3362]

I'm thinking of not using the fuses, does it really matter?

[@giladit77]

@@prakharvj3362 For me it does not matter, it caused me to drop voltage at the output. Without the fuse it works perfectly !!!

[@zohaibalirajput9348]

You need a charger, not a power supply. Charger: CCCV Power supply: CV only CCCV = constant current / constant voltage. Charger: puts out either a constant current or a constant voltage, depending on the state of charge of the battery Power supply: puts out a given voltage no matter what, cannot be connected to a battery Even if you start from a power supply, you still need a charger between the power supply and the battery, to drop the voltage and limit the current. So, you might as well keep it simple and just use a charger. Note: a "Lab supply" is a CCCV type of power supply, and can be used as a charger.

[@rodstartube]

This is just a battery charger, as batteries are always being drained, either connected to wall adapter or not. The concept of UPS is that batteries will drain only when AC wall adapter doesn't provide energy.

[@akshay.kumark]

Truthfully the first video i liked, subscribed and shared

[@dash8brj]

Cute!!! I like this little ups! you earned a sub. I need to put a meter on my router and see how much it draws, and build a mini ups to suit (I have 4 18650 Samsung cells here waiting for a project!)

[@CancunManny]

Ok, so I did a similar setup ( but using a single 18650 and a TP4056 aka HW168. I took a look at your schematic. not sure if the BMS you are using is different, but with the one I used it didn't work. The two wires that feed the step up converter (the in wires) you are pulling from the charger itself with a mechanical switch. With your schematic, the batteries continue to charge even if you turn switch off. Also with your setup, we assume that if the 8.4v charger is unplugged, the batteries are sending their 8.4 to P+ and P- the ones that are supposed to be feeding the step up converter when the power goes out (no charger). With the TP4056 I have IN+ and IN- and B+ and B- which is for the battery side. I provide 5v and it charges the battery. I get 5v on in+ -, and 4.2v on b+ -, if I unplug the 5v charger. I drop down to about .24v on the IN side, and to about 4.12 on the B side. On my setup I have to feed the step up converter with the B side, wires connected to the battery. Not sure if with the 2S BMS the correct way is how you have it, or if you just made a mistake on the schematic.

[@Sorin_DIY]

hi. we need to clarify a few things about your setup. what is the current consumption of your router? I presume at 12V. what charger did you use, 5V & ?A? did you use a TP4056 module without over-discharge protection? what step up converter did you use? my schematic is correct, the 2S BMS use the same connectors for IN and OUT power. the TP4056 module (with protection) has 5V IN and 4.2 ~ 2.5V OUT (from the battery). you cannot use the IN and OUT connection the same way, connected to the step up converter. always use a charging module with protection, or a li-ion cell with protection. if you use the xl6009 boost module, like me, it will not work correctly with 1 lithium cell. the xl6009 has a minimum IN voltage of 3V, and the li-ion cell (+ the TP4056 with protection) will discharge to 2.5V. the step up converter will not work correctly with only one cell. you can use a MT3608 step up converter, because it has a minimum IN voltage of 2V, but it has less power. so the current consumption of your load is important. also if you increase the voltage from 1 li-ion cell (4.2V ~ 2.5V) to 12V, the step up converter will work with very little power and at a very low efficiency. you can watch my video about battery packs and DC converters for more info. considering that you can't use the 5V from the charger and the 4.2V (max) from the charging module OUT in the same time, how will the switching be made between the two, when the mains power is turned off? a BMS board does this automatically. if you use a relay, you will lose a lot of energy. it's doable, but not practical. I still suggest you use a 2S BMS or bigger.

[@CancunManny]

@@Sorin_DIY Thank you SO MUCH for such a detailed explanation. I know between almost nothing and nothing about electronics. I just follow videos. I have no idea how I ended up with 10 TP4056s, and the chips don't even say TP4056, they say HW 168. You ask if I am using with or without over discharge. I am guessing I am using the ones WITHOUT over discharge. I did notice some of the TP4056s I saw on the internet, next to the B+ -, had other pin (wholes) that read OUT+ -. I am guessing those are the ones with over discharge. When I started my project, I thought I had step up converters, but turns out the ones I have are step downs. I have a 12v power supply (that is actually giving 16v) so I am using one step down to bring it down to 12v, and power an alarm siren. I am also using the 12v output to feed a second step down converter to get me 5v, which I am feeding to the TP4056 connected to an 18650. And I have a d1 mini and a relay connected to the batter. I now understand the big flaw with my build. There is NOTHING to stop the battery from over draining, making the battery useless. I am currently running tests with what I have, but looking to purchase the right hardware for my "real" projects. I am getting into the smart home alarm system. To maintain power on the modem/router and the Raspberrypi (where I run Home Assistant) I plan to use a regular UPS. However if power does go out, I would like some D1 minis to stay powered on (like the ones at the doors with the door sensors). I would also like to be able to keep the siren going even if power is turned off. For the d1 minis by the doors. I am thinking an 18650 with a proper TP4056 with over discharge protection, and a step up converter to get the output up to 5v. (I know the D1 Mini only needs 3.3v but the relays one the hall sensor require 5v) For the Siren setup, I would basically do a setup very similar to what you did. Use two 18650s in series to get 8.4v. Use a step up converter to feed the 12v for the siren, and use a step down converter to get the 5v.

[@oofig]

Cool video dude. Wish more people would make videos like these.

[@AndroidUmair]

Subscribed for the quality of humour and of course the quality of content 😎

[@ilovethynos]

You really make soo amazing videos , like i can use all your projects in my daily life and seriously solved my issues🎉❤😊🙈

[@nareshmehndiratta]

best spoken english lecture

[@jamess1787]

Sorin, love your videos. Love your choice of juice. Love your awesome accent 😂👍🇨🇦

[@jyotirani8232]

really great project

[@nimbusapparels4332]

Do we need the voltage indicator? I mean we can just put a switch to the voltage meter and only use it when we need to check the battery voltage! It could probably save a couple of minutes on the backup time. Excellent video!!

[@Sorin_DIY]

you don't really need the battery voltmeter, I used it because it looks good in the video :) you can use it with a switch.

[@CPD-KD6-3.7]

We built a couple of these for out competition bots, they use a 12v access point and it's a pain to have to wait for them to boot up

[@skyrocketofficail]

First of all thank you so much for the wonderful tutorial. There are two things i wanted to ask you sir. 1. What if we connect volt meter after the converter 12volt side? 2. My 8.7v charger don't have auto cutoff circuit when it's full charged. So if i connect power continuously will it damage my Router or Circuit? Thanks Sir.

[@Sorin_DIY]

hi. if you connect the voltmeter after the step up converter it will always show 12V. I suggest you use the 2S BMS from the link below, it stops the charging automatically when the cells are fully charged. the 8.7V charger will still power the step up converter: www.aliexpress.com/item/32863604994.html?spm=a2g0o.productlist.0.0.78a81a17yfgf8N&algo_pvid=7a7a9384-1f05-43f8-af1c-2152aba8627a&algo_expid=7a7a9384-1f05-43f8-af1c-2152aba8627a-1&btsid=0ab6d69f15918369686154295e5c92&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

[@skyrocketofficail]

@@Sorin_DIY thank you so much sir, Really really appreciated your kind advise. this is exactly what i wanted. God bless you.

[@skyrocketofficail]

@@Sorin_DIY Sir, You have really inspired me and i have made it with the help of your video. But there is one problem. It took 5 Diodes in series to convert 12V to around 8.6V and Diodes are getting really really very heat up while charging. For now i have unplugged for safe side. Can you please help in diode heat problem i am so close :)

[@skyrocketofficail]

@@Sorin_DIY I have 12V Charger for input

[@Sorin_DIY]

hi. you need more powerful diodes, 5A or more.

[@girishankargsbs3864]

A great video, but my doubt is why isn't a charging module used to charge the battery ? Only a BMS board and a Step up converter are used....

[@Sorin_DIY]

the battery pack is charged with a charger and a BMS board. the charger can deliver 2A at 8.4V (max 8.6V) using a CC/CV method. the BMS board has all the needed protection features including balance charging. so together they charge the battery pack using CC/CV method, they balance and protect the cells. the step up converter is used only to increase the voltage to 12V.

[@girishankargsbs3864]

@@Sorin_DIY thanks for the reply, i will build it soon with your video as reference ☺️

[@Newb1eYou_]

Sorin dont worry about you soldering those cells try buy "Kweld" spot welder its cheap and many people buy it its pretty reasonable to be honest.

[@ailyntimosa3932]

Nice one Sorin! Keep up this small useful projects and great content!

[@oherman]

Modified a bit, can this be used in DC-driven LED lights as a solar-fed/gridless lighting system?

[@Sorin_DIY]

it will work, but not very efficiently. it needs better components.

[@oherman]

@@Sorin_DIY I'm thinking more batteries in parallel and probably a better BMS. Anything else? Is it possible to also create a relay path that totally cuts off the DC output for the AC charger if the AC charger is not energized?

[@alissonneres5067]

If you are always charging the batteries and using the batteries to supply energy to the router, consider lower the charging voltage of the batteries. The batteries can be damaged if always working on maximum voltage. Lowering the voltage can increase the life time of the batteries

[@arunkumarbarman1300]

You are the best diy guy in the world 🌎

[@TheShani2012]

Watched all your Videos. Thanks Sorin. Nice Chanel with interesting DIY electronic projects. Please do more in the future. Love your accent too :)

[@jamesgrimwood1285]

Interesting. Here in the UK our ONTs come with battery backup units, but all that’s inside them is four NiMH AA batteries and a charger. Although it’s only really needed so that any phone service provided over fibre keeps working if there’s a power cut.

[@christopheralagasi2015]

It works well with my linksys router with the power consumption of 12v 1A. Thank you again for your help. But there is one problem, in battery mode, i only 9.6v and i got 12v when the charger is plugged. I adjusted the variable of step-up converter into 12v while it is plugged on charger.

[@peanut71968]

E-Nerd! Dude? Very happy I ran across your channel. Excellent demo and build. Cheers!

[@g3rsiu]

You can put a 1N4001 diode in series with the charging circuit, so that you do not keep your LED on the charger when there is no electric current to supply the charger.

[@Sorin_DIY]

yes a diode will block the current in the reverse direction, but it also has a forward voltage drop of around 0.9V so the charging voltage will drop under 8V, which is not enough to charge the cells. the charger LED is using only a few mA, it doesn't make any difference in the 6 hours working time of the UPS.

[@whitepawrolls]

Very nice tutorial, and a good basis for other mini ups projects like an emergency cell phone charger. Sure you got those mini power banks they sell, but those are way overpriced. Thank you.

[@Umski]

Nice compact solution and great explanations with a bit of humour thrown in :)

[@yuxuanhuang3523]

Why don't you use the 12V battery with a 3S balance board? I think it will work fine and be more efficient since you step down rather than up and the voltage difference is smaller. Anyway I never thought of using a charger as source with balance shield. Good idea on that part !

[@Sorin_DIY]

a 3S battery pack will have a voltage between 12.6V and 8.1V. the charger needs 12.8v to 13V to be able to trigger the balance feature and overcharge protection feature of the BMS board. so you can't use a buck converter or a boost converter to get 12V. you can use a buck-boost converter, but it will have a low efficiency so it will waste a lot of energy from the battery. as you said the best efficiency is with a step down converter, so a bigger battery pack is needed, minimum a 4S pack (if you use li-ion cells). I got some LiFePO4 cells and I plan to make a better UPS with a bigger battery pack and no switching delay... soon.

[@volodumurkalunyak4651]

@@Sorin_DIYYou do NOT have to trigger overcharge protection on charging. Relying on BMS overcharging cutoff is a no-go.

[@fat_pigeon]

I like your clear and concise explanations of what you're doing in each step. But wouldn't it be better to limit the charge to a lower maximum voltage (e.g. 3.9 or 4.0 V per cell)? That should significantly improve longevity and safety at the cost of a small amount of capacity.

[@Sorin_DIY]

hi. yes, it would be better to charge the cells to a lower voltage, but the charging process is stopped only when the first cell gets to the overcharge protection voltage, otherwise the BMS board will continue to put current into the cells. and this is not good for lithium cells, they are not supposed to be continuously charged (like lead-acid batteries). so if you don't give the BMS enough voltage to finish the charging process, it will charge the cells continuously, because it can't reach the cur-off voltage. for the BMS I use in the video, the overcharge cut-off voltage is 4.3V (±0.05V), which is very high. so I searched for a better 2S BMS board and I placed the link in the video description, it also has overcharge release voltage, and the overcharge cut-off voltage is 4.25V per cell, which is a bit better than the original BMS I used. there isn't any BMS board with the overcharge cut-off voltage of 4.2V or lower, unfortunately.

[@upalimahinda6120]

Sorin, you are the best!

[@Tomas_Prucha]

Really good video! I just wonder from where did you get the laptop battery packs? Is it possible find it through internet? Is it worth to use old battery cells or is just better to buy new ones? I really like your videos since they have useful information and also are funny and easy to understand! Keep going like this ! Definitely subscribed! Thumbs up 👍👍👍

[@Sorin_DIY]

new cells are better, but it will also work with good laptop cells. the laptop batteries are donated to me, or I buy them from local used electronics stores.

[@TaylorSoloaiJR]

Does the voltage booster you use get really hot? I am using a a buck boost converter and it gets hot to the touch and I did add a heat sink as well.

[@Sorin_DIY]

hi. buck/boost converters get very hot, because they work with a lower efficiency than buck or boost converters, so they use more current. also it depends on the load, if your router needs more current than mine, the converter will get even hotter.

[@lifeai1889]

the ups is back feeding! please add a diole in series with the power input

[@DrZipZwan]

diode before the router or before the charger of the UPS ?? and on which rail? + or - ?? Thx

[@lifeai1889]

@@DrZipZwan add the diode before the ups ,and each rail is fine,just to prevent bck feeding to the charger

[@DrZipZwan]

@@lifeai1889 so between the UPS and its charger. not between the UPS Router. got it 😉 Ok is 1N4007 a good option?? Thx

[@lifeai1889]

@@DrZipZwan acording to the data sheet,1n4007is rated for 1A ,so if your router power supply output curnnet is lower then 1 amp than it's totaly fine

[@DrZipZwan]

@@lifeai1889 yep, my router power supply is rated 9v/ 850mA, and I tested it, it barely reach 350mA. I will go with 1x18650 for now, because I dont have access to a BMS board and gona take lot of time to be delivered to me 😒 Plus, we have electricity power generator as backup, but there is a small time interval of 2-10 min during change overs, so I just need this build to last till the take over of the generator... thx a lot for your support, and to ​ Sorin, for its so useful project 😉

[@hamhumtube]

thank you boss. that is much needed content. one question is there any other way keeping 12V charger instead of throwing it?

[@DrZipZwan]

yes, just add a stepdown module to the build, to decrease 12v to 8.4v IN, then follow the schematic 😉

[@Sorin_DIY]

hi. usually the standard adapter that comes with the modem/ONT is very underpowered. it may not provide enough current to charge the cells and run the modem. you need to test the current consumption of your modem and the output power of your adapter, then you can decide if you can use it.

[@DrZipZwan]

@@Sorin_DIY True, usually modem/Router use a very low consumption, I mean during my testing my router was barely reaching 300mA, even on the back sticker consuption is writed to be 850mA! So a 12v/1A is fine for the router but, since the 18650 are amps eater, I think they will get charged very slowly. I guess...

[@dollarbil961]

Superb , felicitari Sorin ! O intrebare, de unde cutia ?

[@Sorin_DIY]

salut. de pe optimusdigital.ro, dar vad ca nu mai au pe stoc.

[@theraque1]

subbed because of this vid. thanks bud! I'm looking forward to making this.

[@Kenny-bw2cz]

Nice little ups. But may I ask you.., can't a power bank (for smartphones) be used in such a way?

[@Sorin_DIY]

no. powerbanks cannot give an output current, while they are charging. you need to modify it to be able to do this.

[@fat_pigeon]

@@Sorin_DIY Depends on the model. Some can.

[@TousMsaneKamlKarS]

You could you use a schottky diode to prevent power trasfer to the power supply.