Victron: please create a default LFP profile

DIY
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1

As many of us have discovered, on devices such as the IP22, Victron has a preset for lithium batteries (called “Li-Ion”) but this preset leaves a lot to be desired:

It’s not well-documented, but appears to have the following settings (unclear, see Link)

  • Bulk: 14.2V
  • Absorption: 14.2V
  • Absorption time: unclear - might be fixed to 30 minutes?
  • Float: disabled
  • Storage: 13.5V

What’s wrong with these settings?

  • lack of Float mode and unclear absorption times are confusing (Link)
  • Storage mode of 13.5V is too low, allowing LFP battery SOC to degrade (Link)
  • “Li-Ion” is a problematic name, as it’s not clear if this means a modern LFP (LiFePO4) battery vs. some other chemistry (Lithium Polymer, or Victron’s own Lithium batteries [which themselves have several variants] etc.)

Proposal: Victron should add a new “LFP” preset for all the DIYers out there who are using non-Victron LiFePO4 batteries.

I propose these settings:

  • Bulk 14.4 (many LFP batteries specify 14.4 +/- 0.2 )
  • Absorb (same as Bulk)
  • Absorb time: (? unsure, perhaps a fixed 1 hour default would make sense?)
  • Float: 13.8
  • Storage: 13.8
  • temperature compensation: Off
  • This preset should be named “LiFePO4” or perhaps “LFP”

Ideally, similar presets would be created for other devices such as the BMV712.

What do you all think?

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I always use the expert settings, but I have been at this a while. I agree the things you mentioned are confusing to someone not familiar with this industry.

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Victron configured the lithium preset for it’s own lithium batteries (and it’s also suitable for most other LiFePO4 batteries).
If you want/need other settings you can create your own preset.

4

And you have already noted a reason why one does not exist.

With the ability to make and save a custom profile based off the lithium preset there is not much more that can be done for all the variations in chemistry and school of thought out there.
Some of the schools of though that vary are the cell mac voltage - how long in absorption - whether or not you should be charging to that every day, the list continues. With that the custom profile is the only way.

Then there is the ability to problem or troubleshooting - something the DIY side of the market struggle with as it needs some knowlege. That is why the forum exists.

Learning to differentiate between battery problem, charger problem due to physical fault, firmware fault, or settings fault. (Or in some cases a wiring fault)

It takes time, but when in diy that’s what you have to put in. Time to do - time to learn. And pretty much what you signed up for.

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A default LFP mode cannot exist! It really depends on your vision, opinions and most of all, the way the LFP is going to be used. There is a huge difference in using LFP in ESS systems versus LFP on marine/boat installations. For the latter for example the float of Victron is always way TOO high. With 13.5V the battery will always be almost 100% charged, which is terrible for the life of the cells. You should not do this. If its being used in an ESS system, it’s less problematic because the cells will not be for a long time at or near the 100% SOC state.
Furthermore, there is really no need to charge with high voltages like 14.2 or even higher. To get a battery fully charged, 13.8 is sufficient. Just use the right amount of absorption time. Way less stress for the cells then charging with 14.2, .4 or even .6. There is enough proof these days that cells get 100% full if charged with 13.8. (and if you have doubts, I can show you my research). So the 14.2 of Victron is a little bit outdated.
Regarding the absorption time, the tail current is even more important. 0.05C or even 0.033C is common these days as a tailcurrent and in my opinion that is leading above the absorption time, which really depends on how deep and long the battery has been discharged.
Long story short; use expert mode and fix settings based on the latest knowhow.

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Agree 101% ! It took me months to search and set my own custom configuration but set Bulk to 14.6 (based on battery mfg recommendation),float 13.8 VDC, and storage (over winter on our wet docked boat on shore power 24/7. I had posted on the forum many times but never got a good answer so hoping more folks are responding to this with how they set there IP22 charger. Also, battery mfg indicated a top balance only when getting to full charge/14.4-14.6 volts therefore the 14.6 Bulk setting?

Post linked in another topic.

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To clarify : I’m talking about the mass-market consumer LFP batteries which are largely coming from China, and are probably over 90% of LFP batteries on the market these days for DIY.

That’s the most common battery a Victron device is going to be connected to, and it would make sense for Victron to offer a profile which works with these batteries.

This is not true - modern LFP cells have thousands of cycles even at 100% DOD and when stored at 100% SOC. Most people are more at risk of calendar aging (e.g. time) rather than cycles or storage SOC.

Perhaps you are thinking of older chemistries such as NMC?

This isn’t good advice - many consumer LFP batteries require 14.1V for the top-end balancing process to even begin. If you charge below this, you deny the BMS the chance to do cell balancing.

If you aren’t familiar with these batteries, I encourage you to do some research: look up some of the common names (WattCycle, SOK, EcoWorthy, LiTime…)

Many of these have very similar specifications, and in many cases, they are literally the same battery being re-branded.

8

You are allowed to disagree with me of course, but, then you also have to come with facts. I might tell you things you were not aware of yet and don’t fit in your world yet, but that does not mean they are not true. First of all, your advice to me to do more study. Well, I studied LiFePO4 for a long long time and read most scientific research which has been done on this topic. Did you?

Now, lets look at the facts

“To clarify : I’m talking about the mass-market consumer LFP batteries which are largely coming from China, and are probably over 90% of LFP batteries on the market these days for DIY.

That’s the most common battery a Victron device is going to be connected to, and it would make sense for Victron to offer a profile which works with these batteries”

That’s a fact, however, has nothing to do with the usage of those cells. They are being used for marine grade batteries (like my company builds them) and ESS systems. So, you are not saying anything of any value here. Using them in maritime installations have other requirements then ESS.

”This is not true - modern LFP cells have thousands of cycles even at 100% DOD and when stored at 100% SOC. Most people are more at risk of calendar aging (e.g. time) rather than cycles or storage SOC.

Perhaps you are thinking of older chemistries such as NMC?”

No, I’m not. I’m talking about LFP. Why do you think Tesla and Apple are recommending 80% instead of fully charged every time? But, okay, let’s go to the real knowhow. This report is of your interest. They tested several stages of SCO for LFP for a longer time and the research shows that the higher the SOC for storage, the more degradation. Just read the report. There are more studies on this if you want to.
Study of aging mechanisms in LiFePO4 batteries with various SOC levels using the zero-sum pulse method - ScienceDirect

Dahn et all: The Operation Window of Lithium Iron Phosphate/Graphite Cells Affects their Lifetime - IOPscience

And this one is a good read too: Systematic aging of commercial LiFePO4|Graphite cylindrical cells including a theory explaining rise of capacity during aging - ScienceDirect

Last but not least: Erik of Nordkyn Design has done thorough study on this subject too. If you did not read it yet, you should. This is ‘the bible’ : Lithium battery systems | Nordkyn Design

“This isn’t good advice - many consumer LFP batteries require 14.1V for the top-end balancing process to even begin. If you charge below this, you deny the BMS the chance to do cell balancing. If you aren’t familiar with these batteries, I encourage you to do some research: look up some of the common names (WattCycle, SOK, EcoWorthy, LiTime…) Many of these have very similar specifications, and in many cases, they are literally the same battery being re-branded.”

This is really awkward. I’m sorry, but LiTime, WattCycle are not the grade A suppliers. They don’t use EVE cells or Winston. Furthermore, it depends on the BMS when cells get balanced. A good BMS can balance on every voltage you specify. It makes perfect sense to start balancing on let’s say 3.4V/cell. If you absorb at 3.45V then GOOD cells have enough time to balance. There is no need to go any further, it only stresses the cell. Again, the proof: Panda did testing: https://panbo.com/charging-lifepo4-whats-the-impact-of-lower-voltages/ and also, a channel you might be familiar with, Off the Grid Garage, did several tests on this.

Also we did several tests on this. In fact, if you set a good tailcurrent with charging and use a good CC/CV Profile, you might get even more energy out of the cell with ‘just’ charging it to 3.45.

Sample 1 shows an EVE LF304 cell charged to the common 3.65V: 307,80Ah and 994.49Wh.

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Sample 2 shows the same cell, but now charged to 3.45V and with a tailcurrent at 1A. Total discharged 308.60Ah and 997.54Wh:

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We also did testing what happened if the cell was charged with 3.45 with a good absorption profile. There are diagrams of it too. But in short; no energy was stored in the cell anymore, temperature and pressure were rising and with a loadcell to measure the pressure in the cell we saw that the pressure was disproportionately high when charging from 3.45 to 3.65. Doesn’t proof anything, but it’s a good sign lithium plating is taking place at that moment.

I’ll leave you with that. Very eager to learn from you which research shows that storage at 100% SOC does not make any difference.

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  1. Apple doesn’t sell a single device with an LFP battery, so that’s not relevant.
  2. You are correct that Tesla used to have an 80% recommendation, but this was before they started using LFP batteries. For their cars built with LFP batteries, their charge recommendation is now 100% SOC.

I don’t feel it’s productive to debate when you are getting these very basic facts wrong.

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You can ask a hundret people about their preferred LFP charge voltages and get a hundret different answers.

I only charge my 12V victron LFP in my work van up to 13.5V absorption and 13.2V float. I dont see the need to push the cells up to 3.55V on a daily basis. But, i use the equalisation function to charge it once in a while to 14.2V, to give it the possibility to balance the cells. Works fine since 1.5 years so far.

Im using a similar setup for the Pylontechs in the ESS, there however through the SOC, since thats much easier to control. Theres no need to balance on every single charge cycle if you dont charge/discharge fully or ask high currents of the cells. But im sure thats a discussion in of itself.

Does it prolong cell life? Who knows. I have no second identical system to compare to. And even if, a sample size of two is saying nothing, so ill never know

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That’s funny. I come with a lot of proof and facts based on research done by very well known engineers and researchers, you come with nothing and just saying that I am wrong:-)

Your knowledge may be outdated but it looks like you are not eager to learn something new. That’s okay. Good luck.

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That’s an interesting setup - keeping the voltage low for day-to-day use, but using the Equalization function (which is disabled in Victron’s Li-Ion setting, and is really meant for Lead-Acid chemistry) on occasion to ensure cell balancing. It’s creative – I like it. :slightly_smiling_face:

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Its technically what the function was used for in lead acid batteries, to bring the cells up to gassing voltage which would then ensure that they all balance naturally. Theres nothing special to the equalization function itself, no fancy voltage spikes for desulfatization, its just another voltage level that can be activated time-based automatically or manually

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Please ignore most of what the member posted above. It is a collection of internet material that is not relevant in the context of commercial LiFe batteries in an ESS.
Apple, Tesla and co and the needs of an individual cell simply does not apply to this use case. It has been discussed to death over the years. If you are DIYing a battery then it is something you need to consider when programming your BMS.

That said a single profile makes little sense. There are variances in the number of cells, different manufacturers have slightly different requirements for charging and ultimately the battery is meant to be managed and provide its own limits, and cut-offs for the inverter.

One size fits all doesn’t work well for shoes, it certainly won’t for batteries.

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And that’s exactly what I said. It’s impossible to have ONE default profile what is best for all situations. It’s depending on the use of the battery what settings are best. ESS it makes perfectly sense to float at or near 100%. In maritime applications it’s not, because sailing boats are not used every day and can be in the box for weeks. Keeping the battery at or near 100% SOC kills the batteries in those cases. That’s what study’s say. My guess is that the different studies are right :wink: Charging to 100% should not be a problem when the battery is being used after charging (ESS). Charging to 100% for a (sailing) boat and no usage has no usage, besides now and then for top balancing. But, of course your views may be different.

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Me, having kept my home emergency backup system with 200Ah of drop-in LFP batteries from a brand that no longer exists on float at 13.6 for literally 8 years straight and still being able to pull 212.3Ah out of them at a 10-hour rate :face_with_monocle:

Sure, 8 years ago it was 214.9Ah that I could pull out of them at a 10-hour rate, so I suppose they’ve been “killed” by a whopping 1.01% by keeping them fully charged 100% of the time… but personally I call that nowhere near worth worrying about.

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Thx Justin. ‘Don’t be a know it all, be a learn it all’, a wise man once said. This is very interesting. Just for my knowledge; it is really a backup system where the cells sit at 100% SOC for near 100% of their time? How many days per year are the cells at 100%?

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364, I’ll say. It only exists in case the grid goes down at home long enough (>60 minutes is my threshold) that I need to power my fridge and such, and that hasn’t happened since I built the system in late 2017. Once a year if I remember, I grab my CBA V from my work test bench and run a capacity test (thus the one day that the batteries aren’t at full capacity) though I’ve forgotten a couple of times, which would move it to 365 days at 100%, except I’ve also moved twice in that time so the system was off the charger for about a day each time, so I’ll call it at 100% capacity 364 days a year.

I did remember to grab the CBA last year, so it was in mid-December 2025 that I pulled the system down and got my 212.3Ah measurement, which was pulling it down at 20A steady until the BMS shut off the batteries.

2 Group 24 100Ah LFP drop-in batteries, a charger (IP65 12/15 for the past 6 years, started out with a NOCO but it wasn’t as configurable), a BMV-712, and a 2kW ProMariner TruePower Plus inverter (inverter output hardwired to the Belkin power strip in the foreground), built into a modified bamboo shoe-storage bench from Amazon back in the day.

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True! But if you actually do this survey, my claim is that you would find some parameters (Voltage, Absorb Times, etc.) statistically very common, because of the cheap Chinese LFP batteries that now dominate and largely use the same cells and BMSs.

Whatever those #s are are, it would make sense for those values to be a preset.

You might say “But what about future battery technologies? Sodium? Adamantium?”

My answer: Victron is amazingly good about updating their firmware - I see many firmware updates per year for many of their products.

If new battery technologies arise, Victron can simply add new presets.

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It is the cycling that kills cells not being held at one actual voltage within the nominal use range. So technically being in float service isnt bad.

And i think all you are doing is highlighting the different schools of thought in cell charging.
The hills people like to die on.

At the end of the day, responsibility land on the owner. And knowing the product you have specifically. Because even between lifepo4 prismatic cells there is different schools of thoughts and of course every manufacturer has its own recipie.

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