Don’t you think it’s reasonable to specify that the default configuration for LiFePO4 batteries described as “Lithium Iron Phosphate (LiFePO4) batteries” states that it is for 16S batteries? And to draw attention to the fact that there are two types of batteries considered 48V that are quite different, add an option for 15S batteries? Something simple like this:
Lithium Iron Phosphate (LiFePO4) 51.2V (16S) batteries
Lithium Iron Phosphate (LiFePO4) 48V (15S) batteries".
Where is that from?
System voltage ≠ (nominal) battery voltage
A 48V MultiPlus is designed for 48V system voltage.
48V system voltage means a voltage range of around 40V to 60V.
(24V is around 20-30V and 12V is 10-15V)
Every battery with a nominal voltage within that range would be considered a “48V battery”
The actual voltage range depends on the battery → see manual/datasheet of your battery.
Looking at the market.
Almost all LiFePO4 batteries are 16S only a few are 15S.
System voltage
Cells
nominal Voltage
12V
4
12,8V
24V
8
25,6V
48V
16
51,2V
No one would use only 3 cells for 12V or 7 for 24V.
It’s just a “coincidence” that 3,2V x 15 = exactly 48V
The “difference” described in that article is nonsense IMO because there is no difference in application of 15S and 16S, both are used for the same applications.
15S is just a bit cheaper because of one cell less.
Even if Victron would add a 15S preset the installer would still have to check if the settings suit the installed battery.
The preset would be 53,25V absorption voltage, I don’t know your battery but for Cegasa or Pylontech that would be to high and need to be adjusted.
It’s NOT Victrons responsibility to provide presets for every battery type. The installer of the system ALWAYS needs to configure everything correctly!
PS: I also saw your post on Facebook and most users there are also saying that you are wrong.
Of course. However, the value shown in the table is not for any “48V system”, it is only for batteries with a nominal voltage of 52.1V (16S).
But for LiFePO4 batteries there are no batteries in this entire range. And there is also not just the 52.1V (16S) battery. There are two very different and well-defined groups: 48V (15S) and 52.1V (16S). And Victron treats in the documents and tools as if there were only 52.1V (16S) batteries. That is the problem.
It’s a somewhat subjective basis, don’t you agree? And looking at which market, the current one, or the one from a few years ago? I have the impression that Dyness, for example, had its entire line of batteries in 48V (15S), and now it has changed everything to 52.1V (16S). It seems that Pylontech is also making this move. In other words, although perhaps in the current market 52.1V (16S) batteries predominate, perhaps there is a significant (and still growing) installed base of 48V (15S) batteries.
Obviously. A 12V battery with only 3 3.2V cells would have a nominal voltage of 9.6V, which is too low for a 12V system. A 24V battery with only 7 3.2V cells would also have a nominal voltage too low for a 24V system (only 22.4V). A 15-cell battery, on the other hand, has a voltage suitable for a 48V system, and depending on the situation, it may even be more suitable than a battery with a nominal voltage of 52.1V. There is a very interesting comment about this in my Facebook post:
"it’s not about savings. The operating voltage range of lead acid (not during charging) is slightly lower than that of LiFePO4. At 4 cells for a “12v” system it’s close enough, but for a 48v system with 16 cells the difference have become quite large. I believe that’s why some manufacturers choose tu use 15 cells instead to bring that nominal voltage back down closer to what it would be on a 48v lead acid system.
Lead acid nominal voltage is around 12.0v
LiFePO4 nominal voltage is 12.8v (3.2v x 4 cells)."
I agree. But what interests me in that article is not that, what interests me is the notion that there are (only) these two types of LiFePO4 batteries for 48V systems and that the 15S batteries were perhaps the most used initially. It is the notion that the 16S battery is not “the standard”, it is just perhaps the one that is predominant in the market today.
If this is an argument for not having a default configuration option for 15S batteries, it is also an argument for not having a default option for 16S batteries. If a default configuration option is being offered for 16S batteries, it is because it is assumed that these default parameters will be sufficiently adequate. That although a fine adjustment can be made according to the specific battery model being used, it will not result in major problems or losses using the default value. The problem is that this is only true for 51.2V (16S) batteries, and not for any “Lithium Iron Phosphate (LiFePO4) battery”, as the option description says! What I am suggesting is, first, just the minimally correct specification of the option provided, something as simple as changing the text of the option description to “Lithium Iron Phosphate (LiFePO4) 52.1V (16S) batteries”! Please answer this question, do you see any problem with this simple modification? But since many people think that every LiFePO4 battery for 48V systems is a 52.1V battery, this change alone may not be enough to avoid misunderstandings, so I suggested adding a similar option for 15S batteries. Just like the existing option for 16S batteries, the idea is not that the option fits exactly with maximum precision for all 15S battery models, but that it fits reasonably well. That’s the idea of having default configuration options.
It is Victron’s responsibility to ensure the clarity and accuracy of the information provided. If Victron is offering a standard configuration option for LiFePO4 batteries in 48V systems, and there are two distinct and distinct types of LiFePO4 batteries for 48V systems, it is Victron’s responsibility to specify in the option description which of these two types of LiFePO4 battery that option applies to.
First, this is not a parameter to say whether I am right or wrong. This is an ad populum fallacy (look it up if you don’t know what this is). What should be evaluated to say whether I am right or wrong are my arguments. Second, this is not even true. Most of those who spoke out agreed with me or found my warning useful and important. I did a survey and found that 55 people reacted to the post (reactions to the post, comments and reactions to comments). Of the 55, 45 people had some positive reaction (liked the post, made some positive or informative comment regarding the purpose of the post, liked one of my comments, liked some positive or informative comment). Of the 55, only 19 had some negative reaction (laughed at the post, made some negative comment or liked some negative comment). Of these 19, 9 also had some positive reaction (45+19 = 64, 64-55=9), that is, only 10 people of the 55 had only negative reactions to the post. Of these 10, none of them said I was wrong, because my post contained:
A report on the existence of two types of batteries, 48V 15S and 51.2V 16S, and obviously I’m not wrong about that, no one said that they didn’t exist, at most they said they didn’t know that 48V 15S batteries existed.
A warning to be careful when configuring. Obviously no one said I was wrong for making this warning, on the contrary, those who attacked me the most for the post used the argument that people should be careful when configuring and see exactly which battery they are using, in other words, they agree with my warning.
A warning about the lack of clarity and precision in the description of the default configuration options. No one said I was wrong about that either, no one said that the description was clear and precise! What they said is that since they believe that the 16S battery is the standard, and since they defend that the installer should not trust the standard configuration, then the description would not need to be clearer and more precise, that “it is not Victron’s responsibility” to make the description as clear and precise as possible. In other words, they are not saying that I am wrong, they just have a different view on the best way to do it. I believe that making it as clear and well-specified as possible is better, they believe that it is not (I don’t know why, it must be just to be contrary). Some also disagreed due to lack of knowledge of the list of standard configuration options, they thought that the options were only for Victron batteries, they did not know that there are generic options, such as the option for LiFePO4 batteries in general, and even options for specific models from other manufacturers. Some also distorted what I am proposing, as you distorted, saying that Victron cannot include specific options for all existing models from all manufacturers, which was never my proposal.
PS: These comments on my Facebook post demonstrate the importance of what I am saying:
"Pylontech is one of the few companies that makes 15s lifepo4 and they blow up constantly
To my knowledge Pylontech doesn’t include over voltage protection in their bms"
“yes they have over voltage protection”
“I have seen people charge to 3.7v on pylontech so I don’t know”
“the pylon tech bms is slow. Bit i have seen people run it without can bus communication and multinsetup with 16 s charging parameters. It does disconnect. Eventually”
@vcleto
OK, we understand. We get it. The manual doesn’t cover all scenarios. Thank you for pointing it out.
The users have understood your warnings and for sure they will be paying attention when configuring.
And the persons responsible for the manuals, for sure will be correcting them after this long discussion, at some point in the future.
Can we call it a day about batteries’ voltage?
Otherwise it will be like this, below…
No offense!
The shown settings/presets are always recommendations and you have to check if it suits your battery and adjust them if needed.
What kind of situation would that be?
A 48V lead battery has a voltage range of around 40-60V (depending on the exact type and discharge and charge voltage settings).
15S and 16S are both well within that range.
A higher voltage is always better to keep the current low for lower losses across the cables.
(That’s why some people are using 17S or 18S)
I don’t see any benefits of using 15S instead of 16S besides the price.
(But you also have a lower capacity, 100Ah 15S are 4,8kWh and 100Ah 16S are 5,12kWh)
Both.
I work with Victron for over 15 years and we also install lithium batteries for many years now.
16S is and was always the standard for “48V” LiFePO4 batteries.
15S is the niche here.
But Alex is right, I will stop here.
Victron knows about that topic and will or will not react to it.
What is surprising is the energy spent on confronting something so obvious and simple. And I think you didn’t quite understand the issue, even though it is quite obvious and simple, because if you had understood it you would be directing your comment to those who are spending energy opposing something so obvious and simple, and not to me who am having to spend my energy explaining something so obvious and simple.
That’s right, the second option is for the Victron battery, the first one is not! What does the second option have to do with the first one?
Yes, I read the parts you highlighted in the document and used them to set the parameter for my battery. This was after I discovered that the parameter given in the table for 48V LiFePO4 batteries was actually for 51.2V LifePO4 batteries. IT IS WRONG TO CONSIDER THAT A LiFePO4 BATTERY FOR 48V SYSTEMS IS ALWAYS A 51.2V BATTERY. There is no law, standard, or anything that establishes this. It is a very simple matter of being careful to make it clear which battery you are talking about and to draw attention to the existence of the two types of batteries. I cannot understand why there is so much opposition to this! Why this insistence on defending that Victron does not make its materials clearer and explain such an important point? Do you think that all professional installers qualified and trained by Victron know about the existence of these two types of batteries and always get the battery manual to configure the system? I am sure they do not! Why not make things easier and not worry about DIY people, who can often be more qualified than Victron representatives and installers? For example, I have a degree in electronic engineering, I studied Victron equipment in depth to assemble my system, and I suffered a lot with the complicated and incomplete way in which many documents are written. At several times I almost gave up and went to buy a ready-made system like those from Ecoflow or Bluetti. When I decided to stay with Victron, I talked to the representatives to buy the equipment, and I realized that I already knew some things more than they did. I realized that they didn’t know about DVCC, for example. Even with many, many hours of study on dozens of aspects and details involved in the system that I designed, purchased and installed, and already knowing much more about it than the Victron representatives, I still hadn’t discovered that there were two types of 48V batteries and that the battery I bought was 15 cells! Even so, I had configured everything correctly, because I am quite meticulous and had taken care to enter the parameters from my battery manual. But I know that most people are not like that, they are not as careful and meticulous as I am. Most people will see a configuration option for LiFePO4 batteries and will believe that selecting this option is perfect! There is no point in you saying that this is wrong, that the person has to get the battery manual to configure it, that it is their responsibility. This will not change reality! There is a distance between the ideal and the real! It is impossible to guarantee that everyone installing a Victron system does what is ideal. But it is possible and very easy to make the materials clearer, more precise and informative, in order to avoid problems in the real world! The documents need to be made considering the real world, and not the ideal, which does not exist.
After many many posts leading aside from the original question: back to topic. So…
No offence, at all, but… basicaly, if you find the documentation to be too complicated, you should NOT build a DIY system. Not even consider to do that. That’s my harsh opinion. It’s for valid reasons that Victron states safety hints in that way.
To demand the manufacturer to preconfig some kind of “fits for the most part to a certain bunch of systems” - setup is insane not to say highly risky for both the manufacturer and the self declared diy guy and has nothing left from the idea of DIY. Expecting DIY to be “customer friendly” is ridiculous… sorry! You are either DIY or customer, not both!
Do one want to impose himself a DIY while only pluging together some preconfigured devices? No! It’s not about the proper cables, the fuses and all that - it’s about absolut everything! Analysis of requirements, matching system design, composition of components, networking, controlling and management, parameter settings and their interdependence, .etc… and yes, cables and fuses. And one has to have more than just an idea of what’s going on voltage an currentwise - you have to have a deep understanding and better be highly talented or trained on that. Or you have a very good insurance which is not willing to refuse your claim if your property is burnt down…
And if one says, the ESS needs constant monitoring, you absolutely proof my point. Bc NO, a proper setup of ESS does NOT need monitoring except for tweaking the last penny out of it every now and then.
With yet another post repeating the same old story that Victron’s documents and tools are for specialized professionals and therefore must be complicated and imprecise, I say, without any offense, that if Victron doesn’t know that a LiFePO4 battery for a 48V system is not necessarily a 51.2V 16S battery, doesn’t know that there are batteries available on the market for 48V systems with 15 cells and 48V nominal voltage, and doesn’t have the capacity to produce minimally clear and precise documents and tools about this, it shouldn’t be manufacturing battery chargers. But the truth is that Victron knows all of this, and is a very competent company to do so, and does not ignore the battery market, so much so that it provides much more extensive, detailed and precise information about the compatibility of the Victron system in terms of communication with the BMS of various models from various manufacturers. For those who know how to do this, care about doing it and are careful to do it, the point I am talking about that is flawed is infinitely simpler and more basic. It is about the basics of the basics when it comes to charging batteries and the types of batteries available on the market. I believe that Victron cares about this and only didn’t do it more clearly and precisely due to an oversight that I am sure they have every interest in correcting and improving. So, in my strict opinion, the one representing Victron’s interests here is me, and not you who paint Victron as a company interested in making things complicated, confusing, imprecise, poorly explained, to be used only by a few professionals (who most likely know less about many points than many non-professionals who dedicated themselves to studying certain points that interested them).
I’d like to write something about that, too. I’m an agricultural engineer. Nothing really electrical science-related, unless we’re talking about electron transfer during photosynthesis. When I decided to build an ESS system using Victron in 2022, I downloaded the corresponding manuals for the devices, printed them out, and spent some time with them. I also want to mention that the programming languages I once learned no longer exist. I know Node Red in theory, but I’ve never used it. The setup and installation were challenging at first, but without any major hurdles. I need help from my children when setting up new smartphones; I built and installed the Victron system on my own. The early days of the DESS in the beta phase were indeed full of surprises, and I often felt like I had to intervene, but that, too, has relaxed and normalized. In some respects, Victron is a bit special, but that’s mainly due to its wide range of possible applications, and on the other hand, it’s a huge advantage over other systems. I can connect at least 15S, 16S or 17S to a Victron system, and I can also choose 12V, 24V, 36V or 48/50V. Various manufacturers can also be combined. Someone should try that with other manufacturers. They sometimes settle on one manufacturer for the next 20, 30 or 40 years because combinations are not possible at all. This variety requires configuring certain parameters and also requires a certain amount of energy to deal with it. I come from Germany, but have European connections. Victron does not just develop products for the Dutch, German or whatever market. No, they produce products for the European and global market. This also means that some parameters have to be adapted for each specific market. Then there are the various possible applications such as PV, caravans or maritime use. Perhaps you should inform yourself about this and be aware of it before buying.
I have a different view and opinion. To me it’s not about a DIY person versus customers. No. It’s more about being a (trained/professional) designer/installer and maintainer versus end-users.
And there is absolutely nothing wrong about a fair bit of monitoring. Sometimes even mandatory. Either by the seller, insurer or (local) law.
To me solar is nothing special, and we inform customers about the limitations , like no or reduced warranty, without monitoring. Enphase being one of those brands.
And in my world where decentralised 3-phase setups with third party AC PV systems on both AC IN and AC OUT next to a couple of Victron MPPT’s is pretty standard, there won’t be support without proper monitoring.
Who do you think that the customer and/or insurer blames in case of an incident? Sometimes something simple as a broken meter can be a real problem.
So yeah it’s not always that simple…but again. I myself have no problem with the documentation. Not at all.
And in case someone decides to take the DIY route,some day they may end up here. Nothing wrong with that. But it’s your own responsibility to do everything within your power to make it work. You cannot blame anyone else for failures.
To me it’s not that the documentation is too complicated, it’s that it leaves too much out. For example, when they moved from screw terminals to pressure terminals in the Multiplus, they didn’t document how those should be used. Even what are supposed to be professional installers are using those terminals incorrectly, resulting in bad/arching connections. (I know how to use the terminals, so didn’t have an issue, but I’m blown away by how many bad installations and how much bad advice I see in the community in just this simple thing. It only grows from there.)
1 Like
guystewart
(Guy Stewart (Victron Community Manager))
37
Hi All,
I have read a lot of the conversation. I think both perspectives are pretty fair and reasonable, I’ll sum them up as:
Victron could do more to make it easier to understand and install their products
Victron can’t cover all situations and configurations, and the installer is ultimately responsible
There have been a few notes recently about the default and pre-configuration options, and the team is aware, and will most likely take some of the good faith suggestions on board.
I agree that 15S vs 16S lithium batteries are confusing, Victron doesn’t help much here, but neither do the battery manufacturers. My strong opinion is that battery manufacturers should supply configuration sheets with their products for how they want their batteries configured with various major manufacturers.
But then I know that isn’t how it always happens in the real world, so Victron should not be obstinate, but do what we can to make things as good as possible for our customers.
I disagree that the 48V vs 51.2V distinction is sufficient for everyone to intuitively understand. 48V nominal voltage is used generically for both 15S and 16S lithium batteries.
Generally speaking the documentation is extremely dense, and a huge challenge to balance the critical information required for a trained technical professional who just needs the facts,
vs the very beginner coming to electronics for the first time with no prior knowledge of anything electrical who needs more more basic explanations,
And then a 3rd class of people who think they already know, don’t try to do any further research or training at all, then make a mistake, and go looking for someone else to blame.
I have personally been working to try improve the situation for all 3 types for many, many, many years now. The only thing I am certain of is that it will require continuous improvement, and that means humbly accepting the shortcomings and trying to find good solutions when people bring forth issues.
The software and documentation teams are aware of this thread, and will use some of the points raised to improve things for future users.
This is one of the problems. The manual discibes the settings but it uses different parameters/names and not 1 exactly what you find in the set up of the devises.
Perfect. I would just like to state again that on my part there was never a demand for there to be default configuration options for all existing battery models to accurately address all their small differences. This actually ended up being a Continuum Fallacy that was widely used in the discussion to oppose my proposal/suggestion/complaint, which was nothing like that, it was just to create an option for all LiFePO4 15S batteries and specify that the existing option is intended for LiFePO4 16S batteries. This is a problem that only appears in 48V systems, for 12V or 24V there are not two categories of LiFePO4 batteries with different numbers of cells (and I am talking about batteries that are currently on the market, not hand-built batteries. Anyone who builds a hand-built battery should already know what they did and should not limit themselves to using any default configuration). And for this reason, because it is something that only occurs at 48V, many people are not aware of the existence of two types of LiFePO4 batteries with different numbers of cells for 48V systems.
Wowa. Long post, I skimmed it. I have said this before already in frustration. Victron makes an excellent product, well known and trusted. I however feel they are purposely shooting themselves in the foot by not at least making a dumb down system that your average joe can just wire up and go through a wizard app that asks very specific questions and sets everything up, apple does this magnificently. Victron to the average joe is a terrifying product because of the complexity of the setup and ambiguous instructions that are subject to exaustive interpretation. They need to dumb it down a little or only sell it through certified installers. They are going to lose out of a very big and expanding market, as economy’s decline people look to save money doing it themselves. Yes victron is more expensive, but if you diy it you end up with a better product at a lower price. When I started my install to finish was 3 months of intensive learning and Karen like rage and frustration, I’m sure I made a fool of myself. It shouldn’t be that way. Just my opinion as a typical human.
For years I installed DMX lighting in nightclubs. There are literally 100’s of thousands of lighting fixtures and the DMX lighting controllers were the wild West. Chamsys one of the largest lighting controllers companies came up with snap in configs, you buy a light that’s not in their catalog is not an issue, you send them a link to the manual and within a day they parse the fixure instruction set and send a config update file and add it to their catalog. New batteries are coming out fast and furious. Perhaps it’s time to adopt this method
I did not say anything of what you say or read out of it, about Victrons may-be intentions or sth else. But, if you want to missunderstand my post in that way, feel free to do so…
My point is not that the documents have to be in a certain way, but that the soon to be user of that stuff has to be able to handle it or better gets hands off. At least for his own safety, bc it is his responsibility. And it’s on Victrons side do decide if they see reasons to maintain or change their docs.
