96S Nissan Leaf EV pack

Hardware diyBMS
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Well, i was loving this project until i found that although it supports 100 modules, it is limiting the number of modules in series to 32.

If you’re thinking about the excuse of someone killing themselves due to high voltage, don’t go that way.
Even inverters that use 48V packs support up to 600V in the PV input side.
People will get zapped in the PV side even if they dont on the battery side.

Will you change the series limit in the official code base? Or will i have to change it myself?
Maybe put a #define in some file with the maximum series cells? So the “ready made” firmware will still have the 32S limit but people can recompile other versions without having to check every file for the limit each time a new version is out.
I have perfectly safe 96S Nissan Leaf EV pack to use and a matching High voltage Hybrid inverter and I am going to use it anyway.

Don’t forget there is a much higher risk of fire due to large currents with massively parallel low voltage packs.

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I’m not sure I like the tone of the message @rjsc, very few people are using as many cells in series as you, and there is a genuine risk of DC arcs when operating over 50V DC.

As to the high voltage DC on the solar side/inverter - well thats not anything to do with me, I didn’t design that system/product.

As open source you are free to fork as needed, but I will warn you now that although up to 128 modules are supported on the new controller, the modules often run into communications issues due to the speed of the comms links between modules, once you go over about 45 modules.

The newer V4.4 modules can support faster communication speeds, but the code has not yet been changed to support this.

1 Like
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@rjsc
Maybe, it is because your natural language is not English, but that comment could easily be interpreted as a threat. Is that really the way you feel about all the work that @stuart has put into this project? I invite you to reconsider and maybe edit your post accordingly.

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Yes, you are right. My native language is portuguese.
I never seek to threaten or harm anyone. I was asking if he could change the series cell limit or else I have no other way than to change it on my own.

I have the original BMS from the car maybe I can simply mount the diyDMS in parallel to be able to check the cell voltages over wifi. But even using the OEM BMS for balancing, the DIYbms still has to support summing all of the voltages from individual cells.

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I did not read it that way, and neither did @stuart. You are, as @stuart points out, free to modify his design in any way that you please, but to write in the same sentence that you intend to publish it gives me the impression that you have no respect for his work and you intend to act like this person DIYBMS v4 ebay sellers. If you read down the thread, you can see the general view of people here is, his conduct is morally wrong. Do you want to be viewed in that way?

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I have no intention to sell hardware ready to use and profit out of someone else generous work.
I was talking about publishing the modified source code as a github fork.
Some Open Source licenses even mandate that we publish any changes made to the code.

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@rjsc, if you want to make the changes feel free to submit a pull request in GITHUB for me. I think you only need to change the values in the drop down list in the html page.

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(Tuga here) you can use leaf spy and a elm327 to check the voltage on the battery(without the car) but i have no idea if the bms will do its job without the car.
There is no good way to fill 96bms in the stock leaf pack, i made a 32s3p full pack with leaf cells and it’s a real rat’s nest.

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@rjsc as several people pointed out, the tone of the message is “wrong”.

Native English or Portuguese it’s wrong.

“Well, I liked till I found out that…”
Sounds the same as " you are a great guy, but your fired because you suck at your job"

I know enough Latin languages to read an insult when one is made.
And this wasn’t accidently.

Perhaps it sounded different in your head, and while being tired of finding a way to get your leaf working, and hitting the brick wall many times… Made you angry inside when you wrote it.

That can be.
Unintended still insulting.

96 cells is a challenge.
Especially with series.
It’s long long line for the data to travel.
While each module talks on its own, it does get on the same highway with 95 different packages of data in front of it.

There isn’t a probelm of making 3 X 32, and series that output.

Perhaps need to spend $30 extra for 2 more controlers, your stability increase enormous.

As the pack is perfectly balanced…
You could use one reading times 3 to have the total pack voltage.

Actions on the relais can be parallel
(The relais) if one NO goes open, the “connection” is lost to the Contactor, making it stop contact.

The emergency brake needed to protect the pack still will work that way

Yes, more controlers
Yes, 3 webpages
Or upload the data to a database and pull what ever you like from there.

I’ve tried 80 cells…
Made 40 ready, and it was already getting crazy confusing.

It might work, probably will work.
You do increase the complexity beyond an easy controllable level.

As several have suggested, and I’ll do the same, please edit your post.
It does piss people off.
As it’s disrespectful to talk this way.

I do wish you all the best and success for the leaf pack.
96 cells, over 300v, is inviting new dangers.

Many DC breakers are limited in voltage, that might be something to look at.

I did see more inverters reaching the market “high voltage” battery packs, around 300v.
Not just 12-24-48v.
That is progress, as the high amperage is often a larger problem then higher voltage.

Exiting times, where lithium energy storage is getting more accessable,
People liking to be independently from the grid.

(Or like me, no grid in miles and miles :crazy_face:)