I like the idea, I would remove the STM32 and just isolate/level shift the i2c of the BMS to the RP2040, if you can remove 1 MCU from the equation it would be much better in my opinion.
@@JensChrBrynildsen That is something I have trouble understanding. I have a robot project controlling 8 servos with ESP32. I don't understand why ESP32 isn't handling whole board
@@darekmistrz4364I'm not entirely sure I'm understanding their implementation correctly but if I am they're using the RP2040 to act as a PMIC i.e handling voltage regulation, battery charging and power pathing rather than using dedicated ICs for it, ostensibly for flexibility and to some degree cost. Since this is very time critical stuff it makes a lot of sense to use a dedicated MCU. The rp2040 being a dual core with some rather unusual peripherals on board probably also helps a bit, the esp32 then handles connectivity and housekeeping. I can't however figure out why the STM is necessary.
Now that’s really amazing, I was busy designing a circuit for my vending machine control board where I’d want when the main power to the board goes off, the esp32 to run on battery for certain amount of time and then shut off itself.. I didn’t want to but had to use the fricking diode mainly a ss34, but looking at your circuit for the input and output protection using the mosfet and a dedicated driver to handle that. I just loved it. Made my own life a lot more easier haha. Thanks a ton for sharing this and how you’ve used the whole logic, it’s absolutely amazing. Cheers to the hard work and efforts! Hats off. 🎉
I would def like to see less ICs but I understand the 3. Would much rather have 2 STM32's and an ESP vs 3 different boards - just for consistency - any reason you couldn't use an STM to replace the RP? There is a significant cost difference between the 2. (borked - completely broken/unusable) Onto the structure - remove the batteries from the board - have a battery connector block (you can use the screw terminal block or anything like that. If you want batteries like you have where they are on a board - make a battery board - it means if we wanted to use an external pack we can - also decreases mobo size. Actually, what I think you can do is actually separate this circuit completely onto a add-on board (board to board connector could be used here) - so lets say someone wanted to use LiFePO4 - you can just change the mod board (which contains the STM and all battery management components) for something that can manage/handle the diff battery type - you would have a std communication proto between that and the RP but gives flexibility and lowers board size. That then just has a connector that has either the battery board, or just connectors for an external pack - but fully managed. Or say the LiFePO4, then you can use that or any other tech later on without having to replace the whole mobo. Power inputs - same thing - screw terminal input. Keep the barrel jacks standard for ease of use - heck you could use std molex type connectors if you wanted - also for the battery side to keep it physically different. I also think remove the ESP as well - put on another daughter board - and have the connectors here carry the USB aspect for programming the other boards. Also, use a USB controller instead of a mux, so all devices would show up same time. - that then can be brought directly to the feature board - or you could just have a feature board that has a USB-C connector on it if someone wanted to program the other chips without an ESP involved. The BMS board can just have a programming header that is USB but unpopulated so for production easy to just program itself during testing - or via the USB controller on the main board. This brings more features since if you changed the ESP to like an H5 or whatever (heck even a rasp pi) - you could have the management OS be able to deploy firmware updates easily to any of the controllers. - since you want the STM as a core controller here - I think maybe a transistor or some way to 'enable' programming that forces the isolation of battery pack. - so eg: you want to push a firmware upgrade to the STM from the micro or just via USB, you pull a programming pin high on the RP or whatever, and it enabled programming mode on the STM and disconnects the batteries so programming doesn't disable the protections - I say this if its even required - if once the BMS has its registers set, can it function autonomously - then its fine - if it cannot, then you want something like this so if the STM gets borked, then batteries stay off. Just for ease of ref, I will call the add-on boards like so: BMS board (with STM), mobo (with RP) and monitor (with ESP) Then for your OLED display - have it a connector from the monitor board instead. Overall you want to make the main mobo as small as possible - lowers production costs as well as makes testing easier. Also means you can replace a borked board without replacing the whole thing. Means it's modular so you can also change things up over time where they may just need a firmware upgrade of one part to use something else. Like say for old style giggles, we wanna use a lead acid battery pack ... we could - it's just the BMS board that would change. We wanna use an Intel SOC with a full OS, NUTS and the likes to monitor and report ... we just replace the monitor board. Or you have now changed things up to handle more current or more connectors .... change the mobo (ofc current to a certain degree - but the BMS board could shut itself down if too much current was drawn - since the flexibility here) You can also make the main mobo simpler and keep it 12v - similar to the chinese mini-UPS units. And then if you want a variety of connectors avail (or 24/48v) - you just have an add-on board with the circuitry to add those features. - this is where an I2C/ISP/CAN connector could come in from the mobo to these expansion boards. You could then have an expansion board for 24v/48v and have it report it's voltage, state and current draw - and even allow control of it from the monitor board. ... think PoE switch - you could make a switch board with PoE ports (or just even passthrough connector for simplicity) - and each port can be monitored back without any hardware changes) The biggest thing is things will change, so why not make it as easy as possible to adapt to those changes ;)
I would love to be able to get this piecemeal or complete. Itd be nice to be able to get the board with the smd stuff pre installed and leaving the rest of the assembly to me including providing the cells. I have a few of this low volt lion ups I got online and they are all trash with lots of ripple, they don't transition from mains to battery seamlessly without briefly interrupting power, or they just eat lion cells after 6 months. I also second the suggestion to have an option to support LiFEPO batteries as they are even better suited for duty in a UPS.
It's neat watching SMD's shift into place as heat is applied. It's almost like they're alive and crawling to their assigned place. This might be a project I need too, since my office UPS is doing funky things. The other day it just beeped once and I have no idea why, but then just a few days later it completely shut off with no warning.
The idea is with a device like this you'll have a full understanding of what's going on with your hardware :) I hope it can one day solve your problems.
The Mosfet power loss also contains switching loss in addition to resistive loss Rds(on). When evaluating them you need to consider switching time as well, not just choosing the one with lowest on-resistance.
Hey thanks for saying this, you've hit on a critical point of power supply design. For a system like an ideal diode where switching happens very seldom Rds-on is the most important metric. HOWEVER if you were building a switching power supply where the fet is going at 500Khz+, of course you need to look at the gate capacitance and gate drive of the FET :)
@@cdoublejj Yeah, simple 3.3V LDO is commonly used to drop from 5V where efficiency isn't a concern. If you're talking about a linear power supply powering electronics ie: wall charger, nah I don't think so.
@@cdoublejjYes, they're simple and reliable. Sometime a little heat for low current circuits are good for outdoor applications top stop condensation/mildew formation, like camera projects.
@@unknown8088928 LDOs are often used because they can be low noise. Use a back converter to get down to 5V, even potentially lower, and then use an LDO to get down to 3.3 V with low noise.
Hey thanks for the comments :) Since it's all software-defined, LiFePO4 and cease charge at 80% could work with some simple firmware changes. Niche application requests like what you ask are what this device strives to do; if you want a simple hardware UPS that only does one thing, look elsewhere! We can't be cost competitive with those device.
I'm currently in my final year of Electrical and Electronics Engineering and I wish this much depth and explanation was available in class. This is infinitely more exciting seeing an explanation of a schematic of an entire application basis, makes learning a lot more engaging and interesting.
Thanks James ! :) we might have something like that coming out later! If you're interested check out the email list in the video description that will keep you updated!
I've been looking for such a device for long! Great project. Please consider 24v version it would be perfect for all the 24v 3d printers out there (this is what I want it for). Also, if this can be connected with a raspberry pi for monitoring in paralleler or replacing the esp32 (I.e. Klipper 3d printer) it would a perfect component for a lot of printers
Would definitely prefer modular, especially the battery mounting and containment strategy. I prefer to keep (non-LiFePO4) lithium cell battery packs in a packages that can be isolated from expensive devices (e.g. motherboard is high cost in terms of time) and keep risk of damage minimal to non-existant in the event there is a failure that causes the battery pack to explode or burn. In your design I'm unsure how difficult it may be to compartmentalize and safely contain the lithium cells without causing ventilation/cooling issues for the rest of the circuitry. In any event, catastrophic battery failure would seem likely to damage the motherboard and possibly requiring replacing it as well.
For simple low power 5-12V projects (like microcontrollers,single board computers, up to ~2A), aliexpress sells UPS boards for less than 1.5$. Yeah, they might not have the efficiency and fancy displays, but they work and they're dirt cheap. If you want battery holders (lke this project) you can find variants with 2 or more holders as well. Just throwing it out there, that an UPS doesn't need to be needlessly complex.
@@timmturner A 1S configuration doesn't need to be balanced. Complexity doesn't necessery mean more safety For simple projects that require low 5V power, a simple UPS, that can be bought already works just fine.
Hey! The RP2040 is acting as a PMIC while the ESP32 is user facing, meaning the user can really hack around with it without fear of disrupting the core functionality. The PID loop for the power delivery (RP2040) is very resource intensive and can't run on the ESP32 while hosting a webserver, screen, NUT etc.
@@interruptlabsThanks for the speedy reply! That makes a lot of sense, and definitely improves the 'hackability' for people who aren't 100% sure of what they're doing.
@@interruptlabsWhat kind of calculations are you running before / after that PID loop that require a lot of time? After checking the firmware I don't see why it couldn't be ran on the esp32! Cool project man!
Hi, I have a question (not exactly on UPS, but) similar field. I have home entertainment system (< 800w) that operate at 120v @ 60Hz but when I move to a country where its 220v @ 50Hz, I want to be able to use it. Step down transformer will provide 120v but retains the 50Hz, there by decreasing the efficiency on the power supply in the electronic instrument (if they have transformers). So, I was thinking of using a Pure Sine wave Inverter (12v to 120v @ 60Hz, 1200w) and feed it with some sort of Power supply that can deliver 12v at 100A !! .. So was thinking of a 1200W rated SMPS, do you think this is feasible?
My only beef with this design is that it uses 18650 cells. Lithium batteries aren't designed for the long term UPS environment. Sealed lead acid batteries are much safer and are better suited for long term charge storage. Lipos form dendrites internally that damage the cells when holding a full charge for a long period of time without being discharged. You could overcome this by doing a maintenance routine where it discharges the cells at regular intervals but for me, the risk of a lipo fire inside my SOHO panel is too much risk. Also, I don't see a need for two microcontrollers. You could use just an ESP32 to handle everything. I love the other aspects of this project though and I feel like this would be a great toy to play with and add to my smart home projects but I would figure out a way to use something other than lipo cells.
now i CLEARLY have not enough knowledge on this subject but is it not that lithium batteries like 18650 are happiest when stored at a not full charge so wouldnt it better to have a few extra batteries and keep them at 3/4ths charge? or is it only bennificial if they are stored at like 30% which makes it not useful at all to try and do that? i dont have a clue but im sure there are reasons that i am just not aware of. obviously very smart people have asked such questions before. but if someone could entertain me i would be greatful.
This is amazing. Can you tell us, how did you learn all this things. Are you an electronic engineer? Did you study that for a long time? I mean for us hobby electronics thats far to advanced to understand. Finally I would like to ask you how can I learn this? Let's say I'm above average intelligence but not a genius.
Why do you need three microcontrollers? do you want to fly to the moon with it? The batteries are monitored by the BQ, OK An ST to set the BQ, OK. Why an RP2040? All three microcontrollers could set the BQ. The ESP32 could also set up Wifi and the BQ and host a web server all in one IC. This would make the PR204 and ST obsolete.
Hey thanks :) The TI BQ76920pw battery manager needs a companion to set it up. The MCU needs to be on a bus created by the bq76920 so that when a fault occurs, the MCU can do something reasonable to clear the fault before the entire system power has been cut out. This MCU must be completely isolated from the rest of the system (IO and power). Additionally, this bus is 3.3V at 90mA, which isn't enough for the RP2040. The ESP32 is a "user-facing" component, meaning the user can fearlessly flash this device without harming the core functionality of the UPS. The ESP32 can be safely removed if the user doesn't need a screen, WiFi or NUT.
@@interruptlabs thank you very much! We all are safe currently (I mean my family). But we have frequent power outages due to heavily damaged electric distribution infrastructure as well as generation. Of course we know that a huge nation is destroying Ukrainian infrastructure. So I'm in search of a good and long-lasting uninterruptible power solution for my router and optical terminal.
12 x 18650 batteries does not a UPS make. It's a toy. And since you can buy for (really) cheap a used UPS from some defunct server farm it makes it kind of pointless. Even if you have to change the battery. I do respect the design though, just don't see the point of it.
Thank you for your effort and making it opensource. Design wise its amazing, especially that one multipurpose circuit block to charge, discharge with batteries. I am gonna try that one. I did made my own ups for powering my home router and pihole and it is in its 3rd revision and is based on 2S4P configuration but its not smart one. Only thing i didnt figure out was what led you to use 3 mcus and i believe it can be optimized to use 1 mcu. If there are options for collaboration in development, i am interested to join.
Thanks for the comment :) ! I appreciate your support. ESP32 - For hacking and customizing your applications. RP2040 - For controlling the realtime elements for the PMIC. STM32 - Battery protection configuration must be on a separate circuit from the other MCUs. There's a good reason to have all three parts: the ESP32 can be safely removed from the device if you don't need WiFi or the screen, but it cannot take the place of the RP2040 or STM32.
You relay dont’t want to uses DC bales sockets as Output. They can easily be shorted while trying to insert a plug and user's could insert an power supply into the output
Love the vieo, but next time please consider the following: 1. Please remove your face from the corner, we can't see anything on the bottom right and miss everything you are pointing out down there. 2. Please STOP ZOOMING!!! It makes it almost impossible to concentrate on the schematic! Gained a subscriber, and please keep up the good work.
I get your what you were going for with the different sized input and output jacks but you should have gone with a more significant size difference. A 5.5x2.5 mm plug can be inserted into a 5.5x2.1 mm jack and can make intermittent connection, so it is still possible to plug the input power supply into the output. A jack with a different outer diameter would have been better but even better would have been to use a different kind of connector, like an XT60 or XT30 where they have different input and output connectors, then you should have used a female connector for the input and a male connector for the output, then there is no way that the user could plug the input power supply into the output.
Yup! Three MCUs :) ESP32 - For hacking and customizing your applications. RP2040 - For controlling the realtime elements for the PMIC. STM32 - Battery protection configuration must be on a separate circuit from the other MCUs. There's a good reason to have all three parts: the ESP32 can be safely removed from the device if you don't need WiFi or the screen, but it cannot take the place of the RP2040 or STM32.
Intersting perspective in case of multiple uC :) Maybe next iteration needs one FPGA with a few RISC-V cores...it will be super fine to watch this kind of challenge ;) Thanks for sharing this +1
at larger ups you might as well replace esp with allwinner h5. get actual os in there so you can run shellscripts like big server admin. i would, it's simpler
Camera sensors price improvements & open source usability would be awesome, but many profitable companies hide behind “security/military” arguments & lobbying it seems.
So inspiring to keep finding people who not only believe but invest energy in innovative, open source hardware/projects. Thanks so much! A DC-DC UPS project has been on my mind for a long time now. Additions like a wide input DC/DC converter (60W 75V to 12V) could result in a more robust design with a wider application range. Just like yourself, my time is limited and so collaboration would be a better way of moving forward. What do you say interruptlabs?
Yes! Thanks for your comment! We believe in developing products that enable users to modify and upgrade while reducing e-waste; this device hits the nail on the head. If you're interested in working with me, send me an email! walker@interruptlabs.ca
@@interruptlabs +1 for the input Voltage, but Higher output voltage could also be interesting. I for myself run a single 19v PSU to power my Home Server (Intel NUC), DSL Modem (using a stepdown to 12v), and my Reolink doorbell. Of course I could boost the 12v to 19v for the server, but that wouldn't be very efficient.
What is this designed to power exactly? I know routers can be powered with just 3x lithium ion batteries, so seeing 12 of them here is pretty surprising - but this also means i have no idea if this is designed to be back up power for laptops since I couldn't find any mention of maximum power output
What a cool project! My favorite diy ups is a meanwell drc100a or drc100b with an appropriately sized lifep04 battery. Just tune the output to the correct top voltage and for 100-200 bucks you can get 20-40ah of capacity at 12 or 24v. Ive put fifty or so of these together and theyre a great alternative if you dont need the fancy stuff. You can just tap off a 12v to usb c adapter or whatever else you need too
this video is pretty much informative , thank you for assembling the circuit, you are very good at explaining the stuff which you made with good voice , indeed i got details from this video, thank you very much once again
Need to be able to plug in battery banks for longer run time. Just make the charging and battery management part of the UPS separate and chain-able (have the primary built in and a plug to expand with daisy-chain style connections). 9 amps is plenty of power the 90 Wh is way too small (especially if you are drawing 9 amps @ 12 volts, that's less than an hour!). There is plenty of resources in the chips to run almost an unlimited amount of expansion storage.
Good Idea will be use a 2x INPUT (or one PoE) who give us option to use input from TWO differ PHASE source adapters. Then this UPS will be perfect for many of my clients setups.
How is this a UPS when it doesn't have mains in and out, near sign wave output, and power factor correction? This seems to be trivially more than a simple DC BMS.
I love the concept of a modifiable/repairable UPS, but this implementation really does not do it for me. As others have pointed out the choice of battery is really less than ideal. If you want to stick with compact, energy dense cells then LiFePo is the way to go, and of course there's a reason lead acid remains the standard when size and weight aren't significant factors. The use of a DC barrel plug as an output is just asking for problems, especially with it placed right next to the input where someone fumbling around in a cramped rack could easily plug in to the wrong one. WiFi-only networking is also a weird choice, considering that UPSes tend not to move very often and tend to be near things they can be wired to. In the event of a power outage I'd be willing to bet that wired ports stay online longer than wifi. Not saying don't support WiFi, obviously the ESP32 has it so you may as well allow it, but WiFi-only on a device that's expected to be plugged in to the wall during most of its operating life is a strong turnoff.
sorry to interrupt you but... the background volume was a bit too much at the start, it needs to be lower than your speaking voice. Top down cam is better than looking up at you, try looking into desk mounted microphone stands and webcams that have the screw mounting. But please don't let my critique discourage you from showing us more open source electronics, in the end open sourcing something will drive down prices even further if it becomes standard and mass produced with the same quality that is intended with the open source ideals... such as Linux dominating just about every server and yet is still a very profitable OS for those that use it and cheap enough for the every man to have their own website.
Super cool project, Ryan! Designing something like this is no small feat! While there might be areas of improvement, going through the process of designing and building this thing, end to end, is a difficult job indeed. Thanks for sharing!
This is so cool! For the final product I'd love to see it customizable. So one can select how many outputs at what voltage they need and how many battery packs they need! I for example need 12V (NAS), 19V (router) and 6V (ISP modem). You can't get this on the market. And I really don't need a lot of battery life. Just enough to gracefully shut down the NAS and router. So please, PLEASE, give us the option to configure the product to our needs and take our money :)
I like the idea, I would remove the STM32 and just isolate/level shift the i2c of the BMS to the RP2040, if you can remove 1 MCU from the equation it would be much better in my opinion.
Yeah. An ESP32-S3 should be able to drive the entire system actually, but great project! Looking forward to see testing of it!
@@JensChrBrynildsen That is something I have trouble understanding. I have a robot project controlling 8 servos with ESP32. I don't understand why ESP32 isn't handling whole board
@@darekmistrz4364I'm not entirely sure I'm understanding their implementation correctly but if I am they're using the RP2040 to act as a PMIC i.e handling voltage regulation, battery charging and power pathing rather than using dedicated ICs for it, ostensibly for flexibility and to some degree cost. Since this is very time critical stuff it makes a lot of sense to use a dedicated MCU. The rp2040 being a dual core with some rather unusual peripherals on board probably also helps a bit, the esp32 then handles connectivity and housekeeping. I can't however figure out why the STM is necessary.
@@oliverer3he is using a BMS IC and using the stm chip to control and configure the IC... I don't know what the rp2040 is doing
Thank you for making it open source! 😊
:-)
Now that’s really amazing, I was busy designing a circuit for my vending machine control board where I’d want when the main power to the board goes off, the esp32 to run on battery for certain amount of time and then shut off itself.. I didn’t want to but had to use the fricking diode mainly a ss34, but looking at your circuit for the input and output protection using the mosfet and a dedicated driver to handle that. I just loved it. Made my own life a lot more easier haha. Thanks a ton for sharing this and how you’ve used the whole logic, it’s absolutely amazing. Cheers to the hard work and efforts! Hats off. 🎉
Awesome! I'm glad you could benefit :)
I would def like to see less ICs but I understand the 3.
Would much rather have 2 STM32's and an ESP vs 3 different boards - just for consistency - any reason you couldn't use an STM to replace the RP?
There is a significant cost difference between the 2.
(borked - completely broken/unusable)
Onto the structure -
remove the batteries from the board - have a battery connector block (you can use the screw terminal block or anything like that.
If you want batteries like you have where they are on a board - make a battery board - it means if we wanted to use an external pack we can - also decreases mobo size.
Actually, what I think you can do is actually separate this circuit completely onto a add-on board (board to board connector could be used here)
- so lets say someone wanted to use LiFePO4 - you can just change the mod board (which contains the STM and all battery management components) for something that can manage/handle the diff battery type - you would have a std communication proto between that and the RP but gives flexibility and lowers board size.
That then just has a connector that has either the battery board, or just connectors for an external pack - but fully managed.
Or say the LiFePO4, then you can use that or any other tech later on without having to replace the whole mobo.
Power inputs - same thing - screw terminal input.
Keep the barrel jacks standard for ease of use - heck you could use std molex type connectors if you wanted - also for the battery side to keep it physically different.
I also think remove the ESP as well - put on another daughter board - and have the connectors here carry the USB aspect for programming the other boards.
Also, use a USB controller instead of a mux, so all devices would show up same time.
- that then can be brought directly to the feature board - or you could just have a feature board that has a USB-C connector on it if someone wanted to program the other chips without an ESP involved.
The BMS board can just have a programming header that is USB but unpopulated so for production easy to just program itself during testing - or via the USB controller on the main board.
This brings more features since if you changed the ESP to like an H5 or whatever (heck even a rasp pi) - you could have the management OS be able to deploy firmware updates easily to any of the controllers.
- since you want the STM as a core controller here - I think maybe a transistor or some way to 'enable' programming that forces the isolation of battery pack.
- so eg: you want to push a firmware upgrade to the STM from the micro or just via USB, you pull a programming pin high on the RP or whatever, and it enabled programming mode on the STM and disconnects the batteries so programming doesn't disable the protections - I say this if its even required - if once the BMS has its registers set, can it function autonomously - then its fine - if it cannot, then you want something like this so if the STM gets borked, then batteries stay off.
Just for ease of ref, I will call the add-on boards like so: BMS board (with STM), mobo (with RP) and monitor (with ESP)
Then for your OLED display - have it a connector from the monitor board instead.
Overall you want to make the main mobo as small as possible - lowers production costs as well as makes testing easier.
Also means you can replace a borked board without replacing the whole thing.
Means it's modular so you can also change things up over time where they may just need a firmware upgrade of one part to use something else.
Like say for old style giggles, we wanna use a lead acid battery pack ... we could - it's just the BMS board that would change.
We wanna use an Intel SOC with a full OS, NUTS and the likes to monitor and report ... we just replace the monitor board.
Or you have now changed things up to handle more current or more connectors .... change the mobo (ofc current to a certain degree - but the BMS board could shut itself down if too much current was drawn - since the flexibility here)
You can also make the main mobo simpler and keep it 12v - similar to the chinese mini-UPS units.
And then if you want a variety of connectors avail (or 24/48v) - you just have an add-on board with the circuitry to add those features.
- this is where an I2C/ISP/CAN connector could come in from the mobo to these expansion boards.
You could then have an expansion board for 24v/48v and have it report it's voltage, state and current draw - and even allow control of it from the monitor board.
... think PoE switch - you could make a switch board with PoE ports (or just even passthrough connector for simplicity) - and each port can be monitored back without any hardware changes)
The biggest thing is things will change, so why not make it as easy as possible to adapt to those changes ;)
Love the schematic explanation!
:) Thanks! I spent quite a while on it.
hrm don't like using barrel jacks for output. if ur gonna do that, at least separate them by a large, obvious physical distance.
I would love to be able to get this piecemeal or complete. Itd be nice to be able to get the board with the smd stuff pre installed and leaving the rest of the assembly to me including providing the cells. I have a few of this low volt lion ups I got online and they are all trash with lots of ripple, they don't transition from mains to battery seamlessly without briefly interrupting power, or they just eat lion cells after 6 months. I also second the suggestion to have an option to support LiFEPO batteries as they are even better suited for duty in a UPS.
Make it stackable with more 18650 modules to expand the capacity! Thanks for the video!
This is certainly a topic of discussion for us!
Or a connection for an external bank of larger cells.
It's neat watching SMD's shift into place as heat is applied. It's almost like they're alive and crawling to their assigned place. This might be a project I need too, since my office UPS is doing funky things. The other day it just beeped once and I have no idea why, but then just a few days later it completely shut off with no warning.
The idea is with a device like this you'll have a full understanding of what's going on with your hardware :) I hope it can one day solve your problems.
@@interruptlabs We understand now we need enough batteries to back up something bigger than a cell phone.
The Mosfet power loss also contains switching loss in addition to resistive loss Rds(on). When evaluating them you need to consider switching time as well, not just choosing the one with lowest on-resistance.
Hey thanks for saying this, you've hit on a critical point of power supply design. For a system like an ideal diode where switching happens very seldom Rds-on is the most important metric. HOWEVER if you were building a switching power supply where the fet is going at 500Khz+, of course you need to look at the gate capacitance and gate drive of the FET :)
does anyone even do linear power supplies anymore?
@@cdoublejj Yeah, simple 3.3V LDO is commonly used to drop from 5V where efficiency isn't a concern. If you're talking about a linear power supply powering electronics ie: wall charger, nah I don't think so.
@@cdoublejjYes, they're simple and reliable. Sometime a little heat for low current circuits are good for outdoor applications top stop condensation/mildew formation, like camera projects.
@@unknown8088928 LDOs are often used because they can be low noise. Use a back converter to get down to 5V, even potentially lower, and then use an LDO to get down to 3.3 V with low noise.
Two features I'd be curious about:
Can it work with LiFePO4 cells?
Can it cease charge at 80% to prolong the lifespan of the cells?
Hey thanks for the comments :)
Since it's all software-defined, LiFePO4 and cease charge at 80% could work with some simple firmware changes. Niche application requests like what you ask are what this device strives to do; if you want a simple hardware UPS that only does one thing, look elsewhere! We can't be cost competitive with those device.
BQ76920 works with Lithium cell chemistry.
I'm currently in my final year of Electrical and Electronics Engineering and I wish this much depth and explanation was available in class. This is infinitely more exciting seeing an explanation of a schematic of an entire application basis, makes learning a lot more engaging and interesting.
Great little board. I love the efficiency focus and logic of the design. Id love to see another version to do up to 24v.
Thanks James ! :) we might have something like that coming out later! If you're interested check out the email list in the video description that will keep you updated!
Yeah. The USB-C output needs to power my laptop.
I've been looking for such a device for long! Great project. Please consider 24v version it would be perfect for all the 24v 3d printers out there (this is what I want it for). Also, if this can be connected with a raspberry pi for monitoring in paralleler or replacing the esp32 (I.e. Klipper 3d printer) it would a perfect component for a lot of printers
Would definitely prefer modular, especially the battery mounting and containment strategy.
I prefer to keep (non-LiFePO4) lithium cell battery packs in a packages that can be isolated from expensive devices (e.g. motherboard is high cost in terms of time) and keep risk of damage minimal to non-existant in the event there is a failure that causes the battery pack to explode or burn.
In your design I'm unsure how difficult it may be to compartmentalize and safely contain the lithium cells without causing ventilation/cooling issues for the rest of the circuitry. In any event, catastrophic battery failure would seem likely to damage the motherboard and possibly requiring replacing it as well.
Is there a temperature sensor near the batteries? I can't see it on the diagram.
Yes. PN TH1 on page 3 of the schematic.
Excellent work!
Thanks :) !
For simple low power 5-12V projects (like microcontrollers,single board computers, up to ~2A), aliexpress sells UPS boards for less than 1.5$. Yeah, they might not have the efficiency and fancy displays, but they work and they're dirt cheap. If you want battery holders (lke this project) you can find variants with 2 or more holders as well.
Just throwing it out there, that an UPS doesn't need to be needlessly complex.
It has to be complex enough to be safe, the batteries need to be balanced.
It's not as simple as you seem to think
@@timmturner A 1S configuration doesn't need to be balanced. Complexity doesn't necessery mean more safety
For simple projects that require low 5V power, a simple UPS, that can be bought already works just fine.
@@hojnikb A 5v UPS is not what this is.
Can't wait when it will be available for purchase.
sorry if i over looked it, but where can i buy either a kit or the pcb?
Nothing yet! If you subscribe to the channel, or the Protectli mailing list you will be the first to know.
Why would you use two micro controllers? What was behind this choice?
Hey! The RP2040 is acting as a PMIC while the ESP32 is user facing, meaning the user can really hack around with it without fear of disrupting the core functionality.
The PID loop for the power delivery (RP2040) is very resource intensive and can't run on the ESP32 while hosting a webserver, screen, NUT etc.
@@interruptlabsThanks for the speedy reply! That makes a lot of sense, and definitely improves the 'hackability' for people who aren't 100% sure of what they're doing.
@@interruptlabsWhat kind of calculations are you running before / after that PID loop that require a lot of time? After checking the firmware I don't see why it couldn't be ran on the esp32! Cool project man!
Really cool! How many watts is the parasitic drain from the control uC and PS circuit?
Cool! We need more open source hardware.
Will you be submitting it to OSHWA?
Looks amazing! One question: are you looking at ways for users to expand capacity? That would be a killer feature!
Thanks for the comment. This is definitely something on the table for later revisions of the product!!
@@interruptlabs Awesome, can't wait to see what you come up with!!
@@interruptlabs Yes, please!
Hi, I have a question (not exactly on UPS, but) similar field. I have home entertainment system (< 800w) that operate at 120v @ 60Hz but when I move to a country where its 220v @ 50Hz, I want to be able to use it. Step down transformer will provide 120v but retains the 50Hz, there by decreasing the efficiency on the power supply in the electronic instrument (if they have transformers).
So, I was thinking of using a Pure Sine wave Inverter (12v to 120v @ 60Hz, 1200w) and feed it with some sort of Power supply that can deliver 12v at 100A !! .. So was thinking of a 1200W rated SMPS, do you think this is feasible?
If they would be daisy-chain-able I would certainly buy this
Thanks for the feedback.
Plz fix too low audio levels. Use good audio normalization.
I was wondering if this was modified or pure sinewave, but then realised there was no inverter, as the o/p was 12v dc!
My only beef with this design is that it uses 18650 cells. Lithium batteries aren't designed for the long term UPS environment. Sealed lead acid batteries are much safer and are better suited for long term charge storage. Lipos form dendrites internally that damage the cells when holding a full charge for a long period of time without being discharged. You could overcome this by doing a maintenance routine where it discharges the cells at regular intervals but for me, the risk of a lipo fire inside my SOHO panel is too much risk. Also, I don't see a need for two microcontrollers. You could use just an ESP32 to handle everything. I love the other aspects of this project though and I feel like this would be a great toy to play with and add to my smart home projects but I would figure out a way to use something other than lipo cells.
I want to learn more about the electronics part. can anyone suggest me any article or video?
audio is either mismixed or echo chambered
Guys, when? Or tell me at least how much it will cost to buy (without batteries).
now i CLEARLY have not enough knowledge on this subject but is it not that lithium batteries like 18650 are happiest when stored at a not full charge so wouldnt it better to have a few extra batteries and keep them at 3/4ths charge? or is it only bennificial if they are stored at like 30% which makes it not useful at all to try and do that? i dont have a clue but im sure there are reasons that i am just not aware of. obviously very smart people have asked such questions before. but if someone could entertain me i would be greatful.
This is amazing. Can you tell us, how did you learn all this things. Are you an electronic engineer? Did you study that for a long time? I mean for us hobby electronics thats far to advanced to understand. Finally I would like to ask you how can I learn this? Let's say I'm above average intelligence but not a genius.
Thanks 👍
Why do you need three microcontrollers? do you want to fly to the moon with it?
The batteries are monitored by the BQ, OK
An ST to set the BQ, OK. Why an RP2040?
All three microcontrollers could set the BQ.
The ESP32 could also set up Wifi and the BQ and host a web server all in one IC. This would make the PR204 and ST obsolete.
Hey thanks :)
The TI BQ76920pw battery manager needs a companion to set it up. The MCU needs to be on a bus created by the bq76920 so that when a fault occurs, the MCU can do something reasonable to clear the fault before the entire system power has been cut out. This MCU must be completely isolated from the rest of the system (IO and power). Additionally, this bus is 3.3V at 90mA, which isn't enough for the RP2040.
The ESP32 is a "user-facing" component, meaning the user can fearlessly flash this device without harming the core functionality of the UPS. The ESP32 can be safely removed if the user doesn't need a screen, WiFi or NUT.
Now lets make this scalable to handle however much load we want
This is really cool.
"UPS" but in reality 12V, would be still nice if you name it in title, now t looks like clik byte
12 batteries? How about 50 or 100 batteries?
can you buy it?
So... did it work?
Yes! Works great!
Do you honestly think we need to be told what a diode is?
I wish I could buy this device in Ukraine.
I hope you and your family is safe.
@@interruptlabs thank you very much! We all are safe currently (I mean my family). But we have frequent power outages due to heavily damaged electric distribution infrastructure as well as generation. Of course we know that a huge nation is destroying Ukrainian infrastructure. So I'm in search of a good and long-lasting uninterruptible power solution for my router and optical terminal.
There aint no way id trust this to power my phone let alone a propper load like a computer.
18650? RIP
12 x 18650 batteries does not a UPS make. It's a toy. And since you can buy for (really) cheap a used UPS from some defunct server farm it makes it kind of pointless. Even if you have to change the battery. I do respect the design though, just don't see the point of it.
Are you going to sell the boards in the future? I would be interested in one to test.
Right now we're gathering interest and feedback, but the plan is to sell complete devices in the future.
Thank you for your effort and making it opensource. Design wise its amazing, especially that one multipurpose circuit block to charge, discharge with batteries. I am gonna try that one. I did made my own ups for powering my home router and pihole and it is in its 3rd revision and is based on 2S4P configuration but its not smart one. Only thing i didnt figure out was what led you to use 3 mcus and i believe it can be optimized to use 1 mcu. If there are options for collaboration in development, i am interested to join.
Thanks for the comment :) ! I appreciate your support.
ESP32 - For hacking and customizing your applications.
RP2040 - For controlling the realtime elements for the PMIC.
STM32 - Battery protection configuration must be on a separate circuit from the other MCUs.
There's a good reason to have all three parts: the ESP32 can be safely removed from the device if you don't need WiFi or the screen, but it cannot take the place of the RP2040 or STM32.
Will there be USB support like in a regular UPS?
Yes! I will have support for NUT over USB.
You relay dont’t want to uses DC bales sockets as Output. They can easily be shorted while trying to insert a plug and user's could insert an power supply into the output
Nice project but why not using LFP batteries? Much less hassle for protection and no fire risk.
Schottky diode only has a forward drop of .2v
Depends on how much current it is passing but yes can be only .2v for some
Love the vieo, but next time please consider the following:
1. Please remove your face from the corner, we can't see anything on the bottom right and miss everything you are pointing out down there.
2. Please STOP ZOOMING!!! It makes it almost impossible to concentrate on the schematic!
Gained a subscriber, and please keep up the good work.
I get your what you were going for with the different sized input and output jacks but you should have gone with a more significant size difference. A 5.5x2.5 mm plug can be inserted into a 5.5x2.1 mm jack and can make intermittent connection, so it is still possible to plug the input power supply into the output.
A jack with a different outer diameter would have been better but even better would have been to use a different kind of connector, like an XT60 or XT30 where they have different input and output connectors, then you should have used a female connector for the input and a male connector for the output, then there is no way that the user could plug the input power supply into the output.
Cool, but why THREE microcontrollers? More cost, more complexity...
Yup! Three MCUs :)
ESP32 - For hacking and customizing your applications.
RP2040 - For controlling the realtime elements for the PMIC.
STM32 - Battery protection configuration must be on a separate circuit from the other MCUs.
There's a good reason to have all three parts: the ESP32 can be safely removed from the device if you don't need WiFi or the screen, but it cannot take the place of the RP2040 or STM32.
Intersting perspective in case of multiple uC :) Maybe next iteration needs one FPGA with a few RISC-V cores...it will be super fine to watch this kind of challenge ;) Thanks for sharing this +1
at larger ups you might as well replace esp with allwinner h5. get actual os in there so you can run shellscripts like big server admin. i would, it's simpler
@@ketasyour reliability goes out the window then though. OS'es are generally easier to crash then a program running on a uC.
@@marcinbielivery cool but pretty complex and extensive 😅
I wonder why they forgot to add an AVR, a PIC, a HC11, an 8051, a M68000 and a LEON, that would be the perfect multi CPU kit ;-)
The next version will strive to have every single MCU ever made, don't worry.
@@interruptlabs, LOL
We're also gonna need some PLCs too 😂
@@interruptlabs i want a sid chip too no 2x sid chips
NEEDS 555's! Lots of them. Blinky LED's as well.
Nice project with some great ideas!
Excellent video! Thanks for sharing! 👍
Hey thanks :)
Now if we could just get someone to do the same with [touch]screens in general - open source hardware would be lovely. Same deal with camera sensors!
Camera sensors price improvements & open source usability would be awesome, but many profitable companies hide behind “security/military” arguments & lobbying it seems.
@@boxcutter0 Mostly CrApple and Samsung lol
So inspiring to keep finding people who not only believe but invest energy in innovative, open source hardware/projects. Thanks so much! A DC-DC UPS project has been on my mind for a long time now. Additions like a wide input DC/DC converter (60W 75V to 12V) could result in a more robust design with a wider application range. Just like yourself, my time is limited and so collaboration would be a better way of moving forward. What do you say interruptlabs?
Yes! Thanks for your comment! We believe in developing products that enable users to modify and upgrade while reducing e-waste; this device hits the nail on the head. If you're interested in working with me, send me an email! walker@interruptlabs.ca
@@interruptlabs +1 for the input Voltage, but
Higher output voltage could also be interesting. I for myself run a single 19v PSU to power my Home Server (Intel NUC), DSL Modem (using a stepdown to 12v), and my Reolink doorbell. Of course I could boost the 12v to 19v for the server, but that wouldn't be very efficient.
Great work guys, this is very promising. Apologies if I've overlooked it but have you made any pcb files public or have plans to do so?
Okay, pretty cool! But can it be scaled up?
Not yet, but thanks for this input.
What is this designed to power exactly?
I know routers can be powered with just 3x lithium ion batteries, so seeing 12 of them here is pretty surprising - but this also means i have no idea if this is designed to be back up power for laptops since I couldn't find any mention of maximum power output
Anything you want! By routers and mini PC's were some of our first ideas.
Only 12V? So I can't use this for my server, or router/switches, as they all require north america 120v input. Did I misunderstand?
For that, you would use a 120V UPS.
What a cool project! My favorite diy ups is a meanwell drc100a or drc100b with an appropriately sized lifep04 battery. Just tune the output to the correct top voltage and for 100-200 bucks you can get 20-40ah of capacity at 12 or 24v.
Ive put fifty or so of these together and theyre a great alternative if you dont need the fancy stuff.
You can just tap off a 12v to usb c adapter or whatever else you need too
Very cool! Is the RP2040 absolutely necessary? The ESP32 has decent PWM capabilities
The idea was the user should be able to fearlessly flash the ESP32 without any possibility of changing the control loop on the rp2040.
Awesome video & awesome UPS/thought process!
A+ stuff here! Thanks for sharing it
And, I'm sure you're aware, but this got shared on Hack-A-Day
Thanks :) Yeah I was delighted to see that!
this video is pretty much informative , thank you for assembling the circuit, you are very good at explaining the stuff which you made with good voice , indeed i got details from this video, thank you very much once again
Hey no problem, thanks for the kind words :)
I like how you used a lot of TI ICs :))))
I find they strike a nice balance between cost, functionality and availability
Hey, you should minimize the use of zoom in / out. Thank you.
Certainly for the next video :)
A ready made control board for a DIY UPS would be a killer product.
Where you bring your own batteries.
A UPS for say 1K watts
Are you going to sell these as a kit the customer assembles, or just as a PCB the customer must populate, or as an assembled kit.
Not sure yet. But if you subscribe to our email list you'll be the first to know.
Need to be able to plug in battery banks for longer run time. Just make the charging and battery management part of the UPS separate and chain-able (have the primary built in and a plug to expand with daisy-chain style connections). 9 amps is plenty of power the 90 Wh is way too small (especially if you are drawing 9 amps @ 12 volts, that's less than an hour!). There is plenty of resources in the chips to run almost an unlimited amount of expansion storage.
Thoughts on using NiMH instead of Li-ion?
This is certainly a possibility in the future!
Good Idea will be use a 2x INPUT (or one PoE) who give us option to use input from TWO differ PHASE source adapters. Then this UPS will be perfect for many of my clients setups.
Can I buy this fully assembled?
Not yet, but if you subscribe to the email list in the description you'll be the first to know!
Which software you use for schematic diagram design purposes
KiCad
@@interruptlabs thank you very much,
I have not tried
How is this a UPS when it doesn't have mains in and out, near sign wave output, and power factor correction? This seems to be trivially more than a simple DC BMS.
It would be great to have a "solder iron-friendly" version without(or with minimal usage) SMD components.
Hola Pablo. quando cambiaste trabajo?
I love the concept of a modifiable/repairable UPS, but this implementation really does not do it for me.
As others have pointed out the choice of battery is really less than ideal. If you want to stick with compact, energy dense cells then LiFePo is the way to go, and of course there's a reason lead acid remains the standard when size and weight aren't significant factors.
The use of a DC barrel plug as an output is just asking for problems, especially with it placed right next to the input where someone fumbling around in a cramped rack could easily plug in to the wrong one.
WiFi-only networking is also a weird choice, considering that UPSes tend not to move very often and tend to be near things they can be wired to. In the event of a power outage I'd be willing to bet that wired ports stay online longer than wifi. Not saying don't support WiFi, obviously the ESP32 has it so you may as well allow it, but WiFi-only on a device that's expected to be plugged in to the wall during most of its operating life is a strong turnoff.
May I ask you a question, who the heck are that Hardware Hackers? What they do?
sorry to interrupt you but... the background volume was a bit too much at the start, it needs to be lower than your speaking voice.
Top down cam is better than looking up at you, try looking into desk mounted microphone stands and webcams that have the screw mounting.
But please don't let my critique discourage you from showing us more open source electronics, in the end open sourcing something will drive down prices even further if it becomes standard and mass produced with the same quality that is intended with the open source ideals... such as Linux dominating just about every server and yet is still a very profitable OS for those that use it and cheap enough for the every man to have their own website.
i love this how ever i would like to be able to use a combination of batteries
Super cool project, Ryan! Designing something like this is no small feat! While there might be areas of improvement, going through the process of designing and building this thing, end to end, is a difficult job indeed. Thanks for sharing!
Thanks for the support :) !
I was working on such but now it over.
Will this drive 12v 8a draw? Or any option to have this possible, such as high drain 18650s
Yes it will.
Why Barral Jacks? They are the worst! no locking at all if it gets bumped power is out. I would love to see these projects use locking connectors.
Prototype board shows six 18650's but I guess that will be changed to twelve in the final board?
A great work, thanks
Is there a way to use wired ethernet ? UPS is just about the last device I want to see in WiFi network...
if i may, which program did you use for the schematic, love the video thx i liked and subribed
Hey thanks for the support! Schematics we're all done with KiCad.
thx mate i love your passion and wish that i too one day can share my experience with you@@interruptlabs
This is amazing!!!
Can you do one for 240V now :D
what name your software design Schematic ?
Music is not the focus. Get control of the line levels..
Will You share pcb design or part list to make one
Can we see test video? Thank you
Will you also publish the Gerber files so we can order the pcb and a BOM?
Why use two MCUs? You can put all sotfware in the ESP32.
Oh, I didn't pay attention, there is a third MCU in the schematic. It is way too many microcontrollers.
great work bro!!!! do you have an store where I can buy from you 2 or 3 of those UPS?
This is so cool!
For the final product I'd love to see it customizable. So one can select how many outputs at what voltage they need and how many battery packs they need!
I for example need 12V (NAS), 19V (router) and 6V (ISP modem). You can't get this on the market. And I really don't need a lot of battery life. Just enough to gracefully shut down the NAS and router. So please, PLEASE, give us the option to configure the product to our needs and take our money :)