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For another approach, see my poorly named new thread Taves BMS I use an attiny that measures the cell voltage and communicates via 2 wire optoisolated serial. You daisy chain these cell monitors together sending the info to an ESP32. I have made the cell monitor PCB that has 4x cell monitors...

Right now the system is collecting every 2 seconds. The cells are delivering the data in .4 secs for my 8s pack, so I can trivially go higher. Anything can be stuck into csv, so I don't see the point of that. I agree that I have not tested adequately yet. I should be able to heat my...

In my case 9600baud is fine for a 16s (48V). So unless someone needs to 32s, or what @Roqm's 24p13s, the additional cost of the 6N137 is not worth it. It's no big deal, but the WROOM-32D has a PCB antenna that's included, and no need for the dangling thing.

Excellent, tell me what you need/want. Speak up if you want to give it a go. I have boards that are working fine, but I have new designs with minor improvements waiting to be ordered when JLCPCB has the attinyx41s in stock. Alternatively one can hand solder the SMT attinys. Or find another fab...

Except that if you simply clamp the cells in the obvious dimension, you are dramatically reducing the surface area necessary to get rid of the heat. At higher charge rates, you have to get rid of heat faster. In their tests, I believe they monitored the temperature, and they don't say whether...

Wrong! The EDECOA is a high frequency inverter. Sorry about that.

The max cells you can connect is limited by the speed that it can collect all the cell info. I need to do more experiments to see how fast I can raise the baud rate, and trim the turn around time on each cell.

Why did you invent this nonsense?

The multiplus is different from the compact. I can't remember what detail the compact is missing, but it won't work.

I bought the 4kw WZRELB. $460 on ebay shipped to me. 1) I realized my victron multiplus compact 24/2000 is a low frequency unit. Even though it is rated at 2kw and 4kw surge. My opinion is that Victron underrated it. Neither unit will start my air conditioner. I started it from home power, then...

I am buying 16 30 cell flexible sunpower panels from China. My thinking is that 2 will fit under the 330watt fixed panels and I can support those fixed ones with 3 slides to reduce the flexing of them

What are your thoughts regarding active cooling, and what about heating? OK, post a link. I agree that this design will apply towards all the aluminum lifpo cells and maybe this thread is more about the 280ah/Xuba. They must all come from the same factory. They are always blue.

Yes, and no. Right now my panels are effectively connected straight to the battery. There's an SSR (effectively a relay) to connect/disconnect them. That's really the only SCC that is needed. The MPPT part is a totally separate functionality from the BMS. It needs to set the voltage the panel...

Never mind, I found some prices.

I am working on a design for my class A RV that will get me close to 4kw. Here's my plan: I want 60 cell panels so that I don't need a solar controller. These are very common and are typically .5$ per watt, or even less when used. Higher efficiency modules probably do me no good, because it...

I suspect this won't work because the lithium battery has nearly zero impedance and thus it is a short as far as this power supply is concerned. This would deliver all the amps it can, then trip its own protection and stop. How annoying.

True, I agree that I should look for one that has an adjustable low volt shut off. I get the appeal of an all victron implementation. Once you throw in the SBMS0, the useful, clean and very intuitive user interface gets more cluttered. I wish all of these vendors would deliver their UI via...

I think so too. I think I found a water tight gland for it and will post when they reply that it fits. The gland has dimensions of it's opening, but the wire has no dimensions, so I can't be sure.

Right, I agree. Originally I thought my victron multiplus compact would work because it does have a remote switch, but I just realized last night that it has 3 settings, off, charge only, and charge and invert. Thus I cannot control them independently. This is why I'm looking for two separate...

From Dacien's forum, they referred me to https://www.victronenergy.com/upload/documents/Manual-Connecting-other-lithium-battery-systems-to-Multis-and-Quattros-EN.pdf Quoting that document "The Multi or Quattro needs to be of a recent type that has auxiliary inputs. " I found that aux input in...

Agreed True Define "great performing and VERY robust". What does the solution I am providing not do that would lead you to a solution where you are spending $7 per cell instead of $1 (admittedly a very lame comparison because I am only pricing the main chip)? The LT8585 will do active...

True, but on the other hand, it seems to me that a lot of the BMS choices are rather poor. 1) I don't see the point of BMS that has the circuits to deal with amps of the system. Just like we do not include an inverter or charger in the BMS circuit, which totally depend upon the amps, there's no...

I still have no seen any engineering reason that this application requires more accuracy than the attinyx41 delivers. BiduleOhm provided his opinion, but there was no justification for his opinion that related to this particular application. Right now, if I were to design a new 4x cell board, I...

What does this mean? Are you saying that the whole battery consists of 2 strings of 16 where one string has 2P and another 3P? I assume no, but ... I did not find a satisfactory explanation for this heat. For me, the 2 different hot spots, one at the negative terminal and one at one of the...

I wish we could edit our previous posting. My previous was rather poor. My first paragraph really had nothing to do with the low C issue that was quoted by me. I mean that at 750 cycles the no fixture version seems to have 96% capacity and the fixture version seems to have 94%, and the "red...

I just opened my Victron multiplus compact 2000/24 and realized that it is a low frequency unit. I assumed it was high frequency because of the shape and that it says that it has peak of 4000w. But there seems to be a big doughnut that looks exactly like a low frequency unit. Maybe they are not...

To a large degree that is exactly what the browser and http is. The different UI requirements for each different device can be rendered in the browser and delivered via the ethernet standards without colliding with each other. The different devices have different UI needs and there is really no...

I'm an idiot. Bellevue WA USA

It has wifi (and bluetooth) built in, so I set it up as a server and the user points a browser at it. Below is a sample of the UI. The esp connects to a wifi access point, and makes it's own hotspot. In my RV, the wifi router is powered by the batteries, which can be shut off by the BMS. If...

It currently handles any Ns you please. The wired cell monitors are individual devices that happen to be placed 4x onto one board. They transmit their data serially from one cell to the next. There are jumpers that enable you to bypass the individual cell monitors on the board, so you can wire...