16S "all-in-one" release and installed [DIYBMS]

[@choban007]

I thoroughly enjoyed watching all your videos in one sitting. I'm blown away by your talent and dedication. You're truly remarkable!

[@StuartPittaway]

Thank you very much

[@rubenfernandez4070]

Excellent work. I'm testing the all-in-one together with the v4.6 controller and it works very well. I did a test and the integrated current meter also works on the negative side of the battery. This opens the possibility for battery systems with voltages higher than 85V, using a voltage divider.

[@StuartPittaway]

Thanks for the info!

[@wahabhabeeb8614]

From Nigeria. I have always enjoyed your videos.

[@StuartPittaway]

Awesome! Thank you!

[@EngineeringNibbles]

Been looking for an affordable one of these for large series strings!

[@houseofancients]

Once again awesome job Stewart !

[@StuartPittaway]

Thank you! Cheers!

[@dittagecoeco2738]

Awesomeness! Thankyou Stuart, ciao from Italy

[@StuartPittaway]

My pleasure!

[@PlexMulti]

Ευχαριστούμε!

[@StuartPittaway]

Thank you

[@PlexMulti]

Where can we buy one unit ? I want to test it

[@kiwiscanwifi]

grwat one.. would love to see the active balancer built in to your passive plug in board.. save half the cables.

[@StuartPittaway]

Cool idea

[@diegovinicius5316]

Offgrid andy and stuartt. 👏👏👏

[@StuartPittaway]

I'm in conversations with @OffGridGarageAustralia

[@maciejbromberek131]

Hi Stuart. thanks for the great work. I have ordered some pcbs from jclpcb. they do not include the connectors. can You send links to the connector types for the all in one. maybe You have also the links where to buy them?

[@StuartPittaway]

Hi, all parts are from LCSC and the catalog numbers are on the bill of materials/BOM files. You can also see them in KiCAD if you download the design from GITHUB.

[@maciejbromberek131]

@StuartPittaway Thank You! My batch of all in ones arrives Friday from JCLPCB and the remaining parts that where not in stock I got.from mouser.

[@christopherstaples6758]

now that is tempting , is it going to be like other bms's that can only work as 16s or will it allow 12s 13s etc to be used as well ?

[@StuartPittaway]

It works from 8S all the way to 16S as a single board.

[@mototunski]

thank you for your great job, Stuart; is it possible to add an event "any cell balancing" to deactivate an active balancer breaking its the RUN jumper circuit?

[@StuartPittaway]

The 16S monitoring board has a relay output which will automatically switch on/off an external active balancer. I'll include that in another video - didn't want this one to get too long.

[@mototunski]

@@StuartPittaway it would be really great if you could add this feature into the ESP32 event list also 🙂

[@remix381]

Andy sent me your way !!

[@StuartPittaway]

Hi!

[@PlexMulti]

Nice Keep up the good job

[@StuartPittaway]

I will try my best

[@andrewbowden1076]

What is the power consumption of the boards? I was thinking of doing the individual monitors, but the more I think about it, it's likely that this new 16s board uses less.

[@StuartPittaway]

The individual boards are very efficient in power requirements, the CPU is put to sleep between each request so consumes very little current. The 16S board is always powered up and running, but still only consumes 20 or 30mA - hardly anything in the scheme of a large battery setup.

[@andrewbowden1076]

​@@StuartPittaway I saw that you restocked the main boards yesterday and couldn't help myself! 🙂 Good work Sir! Thank you for the reply.

[@jnsaff]

There was a mention some time of a plan to sell these or a group buy. Has anything come from that?

[@StuartPittaway]

Not yet - I'm considering setting up an Amazon shop to sell them

[@witekgrzegorczyk3470]

Hello Stuart Can connect 16x cell monitor with firmawere 4,9 + 1 pc "all in one" to BMS ?

[@StuartPittaway]

Probably - I've not tested that combination, but it should work, they both "speak" the same communication protocols.

[@StikDragon]

looks really good, nice work. i'm planning on upgrading from a medium sized lead acid installation to LFP next year and I'm keen to DIY it so your project is of interest to me. i was thinking that another advantage of your older model with individual boards on each cell is that interconnect resistance shouldn't be an issue, right? this all-in-one solution will see any resistance as an extra voltage on a cell during high load. my use case is probably going to involve a few 70mm^2 40cm cables linking a four separate 4S batteries into one 16S. each of those cables will see maybe 10mV across them under full load and i think the AIO will interpret that temporarily as a higher voltage on those cells. do you have any thoughts? you said there's a 100mA balance current in this particular model. how did you decide on that value? is there a rule of thumb (eg. "[X]mA per 100Ah of battery") or is it just something that you've worked out empirically? from your real-world testing of this system when a cell (i assume you're using something in the ballpark of 300Ah?) needs to burn off some energy what sort of time is it taking to do so at 100mA? I'm trying to get a feel for if 100mA is sufficient for the 1800Ah battery i'm planning. my gut instinct is "no" but i'm keen to borrow your experience here :) I'm going to use good quality cells, so i don't expect them to need a lot of balancing during use but i also expect this to last for a great many years and it's unclear to me how well matched the cells will stay over time, and i don't want to find that in five years' time there's one cell that's spending 100% of its time balancing and yet still creeping up in voltage. if i needed a higher balance capability then would it be trivial to replace the load resistors with larger external ones, or will that require changes to other parts of the BMS? i'm also considering building this as 3 smaller banks each with their own BMS. what support does your solution have for parallel BMS operation? any other considerations? cheers

[@StuartPittaway]

Lots of questions, which are not that easy to answer unfortunately! Most people are using active balancers these days, so although this design has passive balancer - it rarely gets used as the cells are taken care of using active balancer. The 100mA balance is per cell, and is a trade off between usefulness and the energy/heat generated by balancing and preventing really hot temperatures on the board. Are you planning to build a 48V system?

[@StikDragon]

@@StuartPittawaythanks for taking the time to reply :) Yeah it'll be a 48v system, i'm aiming for about 80kwh. Does DIYBMS have any support for parallel batteries with independent BMSes?

[@StuartPittaway]

@@StikDragonyou could add a 16S monitor onto each parallel battery bank - and a single controller would monitor them all.

[@anthonyevans7911]

Hi Stuart, great video, as a patreon also, its great to see this development. any idea on the total cost per board Stu, both in just the pcb from jlc and the final build cost? I have 4 of the bms systems running managing batteries in my little circle of friends systems. Id be interested in testing one of these tho. Also, I see a reply of yours about the possibility of you selling them, thats a great idea, altho may I add a word of caution. We bought a diverting device years ago (before the battery storage) called a Robin Emley device, to divert the unused solar into a immersion system. Worked flawlessly. Robin sold them in "kit" form, with very little home assembly required. some less techy folks wanted it fully built, thats where his problem came. As his device was so good, and a hobby type "diy" device like this, it outperformed major seller devices and was 10th of the price. They didnt like this and reported him to trading standards. As a "built device" if selling he had to obtain a CE mark accreditation, something very expensive and time consuming to do, and not worth his investment. So, please bear this in mind, as some BMS manufacturers may see how good your device is, (and it is) and may want to create issues for you as they see you as a threat and taking buisiness away from them. Sold in "kit" form with very little to do at home (even as little as bond a heatsink perhaps) then you do not have to get CE marking accreditation. Loving you work Stu, and thanks for doing it.

[@StuartPittaway]

Hi, I'm aware of Robin's device - I spoke to him about that whilst he was developing it. Thanks for the comments, I don't plan to get anything CE marked (yet) - but that also pushes the price per unit up

[@anthonyevans7911]

@@StuartPittaway robins service is awesome. Still got it but its our of circuit now that the battery gets all the excess.auoweb sevice tho, best on the market

[@cgmarch2359]

Hi Stuart. I know this is offtopic.. maybe you can help The 500a Victron shunt..is it 0.25% precison? Any markers on it or the documentation? Thank you for all the work you are doing

[@StuartPittaway]

Not seen any indication of the accuracy or manufacturer - sorry

[@cgmarch2359]

Thank you for fast reply. How about the one from Murrata you are using? Trying to figure if I should buy a 500a Victron since is around 30euro where I am

[@StuartPittaway]

@@cgmarch2359 to be honest I've had that shunt for so long I'm not sure of the model number! The current accuracy is important but not critical, if you are within 1% that's great

[@hottractor1999]

Ha ha, 'a bit of a mess', I'd be happy if mine was that nice looking. :)

[@StuartPittaway]

Its way messier than it start out though.

[@fahrimertdincer8421]

i wonder is there a posibility to change disyn to use 6v cels or 12 v or 24 v cels to create 48v battery whit that you can use your old batterys

[@StuartPittaway]

The cell monitors are designed to look after single cells in parallel, so wouldn't be suitable for 6/12/24V cells.

[@chriswykes2319]

What torque do you tighten your terminals to ?

[@StuartPittaway]

Normally around 4 to 5Nm

[@GauteKorsnes]

Hello Stuart! How does it work when you are using both active and passive balancing at the same time? And, do you plan on using the relay output of the battery board for activating the active balancer? Keep it up, this is awesome work!

[@StuartPittaway]

Yes, absolutely. Didn't want to make the video drag on too long - I will be using the relay output

[@GauteKorsnes]

@@StuartPittaway great. Do you use any specific config when using both active and passive at the same time?

[@daskasspatzle2396]

I probably would have put the cells into a new box, while ripping everything apart... Nevertheless well done 🙂 And by the way, nice beard ;-)

[@StuartPittaway]

I had this box custom laser cut and made to my own design, but agree it would have been a good time to move to another enclosure.

[@PlexMulti]

Does it works with 8s batteries?

[@BagheeraTube]

Yes

[@StuartPittaway]

Yes.

[@CrAzYDr1veR]

Hi can this be linked to older cell modules or are you restricted to 16s?

[@StuartPittaway]

Technically it should work, but I've not tried it

[@JosephHouse-qt5tp]

Does this support an external contactor?

[@JosephHouse-qt5tp]

I see the relay output, what voltage is this output and what is the max allowable current draw on that output?

[@StuartPittaway]

The controller boards support the contactor

[@willempje65]

At 9:03 there is a big resistor in view. Resistors just burn energy into heat (what our planet is dealing with). Why not try to get excess energy from full cells to cells that can take charge? My 2 cents for today.

[@StuartPittaway]

This is a passive balancer, as you say just turns energy into heat. An active balancer is also fitted which moves energy across the cells, generating little heat/loss during that move.

[@johnnymac1976]

If you are referring to the large gold resistor, that is a pre-charge resistor. Its only purpose is to limit inrush current when connecting the battery to inverters/chargers etc...