I did not follow up of DIYBMS for a while, to busy building my Perfect Powerwall
(One of the things is bus-bars, often highly underrated part of the build. Tin plating when you are new to the whole plating stuff isn’t that easy but nesececery step to prevent galvanic corrosion with aluminium terminals of 280Ah cells)
@stuart, I think your DIYBMS have evolved far beyond people reusing laptop cells to make cheap “Powerwall”.
With current pricing of LiFePO4, being cheaper than lead acid, it’s more and more available.
Take me for example. I have [email protected], 52 kWh Powerwall, max charge/discharge 250-300A
The cells costs about 5000-6000 USD include transport to Thailand.
(At my start in February the price was higher, if I buy today it’s under $5k)
And after 3 different expensive China BMS failing on me, I’ve decided to put my thrust in the DIYBMS community, lead by you, Stuart.
Amazing well I must add.
Yes, I could have bought electrodamus, and if he would have 48/51.2v I might have.
Double 24v is not a real solution but workaround.
The Batrium at + 800 USD… way to expensive!! (If there are valid alternatives)
Especially as it doesn’t do much more then the DIYBMS… (or any other BMS for that matter)
I totally understand the decision to not make it available for sales or free share. (Perhaps not agree)
If you don’t know what you are doing, do not play with this type of stuff!!!
It can/will burn your house down. And probably the insurance will say it was user error, own fault, about the same as arson.
Probably why the Batrium is 800usd, to deal with all the possible lawsuits
Being member of the forum of Will Prouse, I do see high potential for DIYBMS.
Like @John_Taves stated a few hundred posts earlier, many potential users are scared away with the need to solder and program IC’s…
(What is so easy following your guidelines, a monkey (=me) could do it)
JLCPCB does 99% of the soldering, if they have all the parts in stock.
For years I’ve looked at the people who program adruino as wizards… as it looks magical.
Writing complex software is different story, the programming part is easy, but…
For many people an issue!!
While I totally understand why you don’t want to sell/give away as (almost) turn key solution, programming attiny or soldering skills have no influence on the skills of building a Powerwall.
When I wrote about missing a few cell modules, you advise to ask in the group if someone could spare a few.
While great thanks (no sarcasm) for the suggestion, all the people honor the license, and no one was willing to break it and send me a few for free or cost or pay.
You get my dubio?
If a friend would ask for my help in building them and use for his Powerwall, I would break agreement to do so.
I truly love the DIYBMS for its
- modular setup.
- per cell module, each capable of balance “high” wattage (important feature. While it should not need to burn off 850mA, if it does need to burn off additional, it’s great peace of mind to know that it will be well equipped to to the job, not like Daly with 35mA for the whole pack)
- easy setup
- temperature rules
I really like your input and improvements.
Am I wrong or did you add ethernet option?
That would be great addition!!
As WiFi isn’t always that stable. (Compared to cable)
I do use the Temperature measure of the DIYBMS.
Looking at your setup, you decided to take the DIYBMS cell monitor modules away from the cells.
That’s a way of looking at it that I never did!
I understand the ease of access, and extending cables won’t really hurt it’s cell voltage reporting.
It does loose the cell temperature measurement.
Totall underestimated part of BMS!
I don’t talk about freezing point, I talk about cell health.
More or less like humans, same nice temperature range.
They are comfortable at the same temperature, perhaps better with little higher (+45) and less with lower (freezing)
Still they should not get too far above 45, 50-60 is stretching it, and the cells need to be cooled.
Henceforth the importance of temperature measure and the ability to act on it.
Not just an aquarium temperature sensor
MyPowerwall have 80 cells.
(Yes, if I bought now it would be 64* 280Ah, but I have 32* 280Ah and 48* 152Ah)
The temperature inside this (almost) massive block of LiFePO4 can/will rise at higher (+100A) loads to a range active cooling is needed.
Temperature difference will give different readings on the cells, that is crucial.
Or so my understanding.
I love the work you do and the leaning path you are on.
Stubborn like me and hard to get of taken route… Unless proven needed.
If I understood correctly you stripped out the temperature settings/ rules for relays.
I didn’t install your version yet.
Still in progress of building my Perfect Powerwall.
Something that is supposed to last a decade or longer without any issues, you don’t build in 10 minutes.
Better take 10 days or in my case 6 months
Please let me know if the temperature sensors are still usable for the relays in your software version.
Please let me know if you have added option for UTP cable, and how to get that version of controller board.
(Or perhaps it’s a new Stuart version, that I need to read up about)
@stuart, what’s the status on the Shunt??
10 August you shown this great progress
That’s a 150 posts or a month ago
Really like to know how it’s progressing!
It can be I missed a few post’s, as far as I could see, that’s the last progress about it