On 2024/10/22 at 5:09 PM, Coulomb said:

I see the battery voltage going  to 55.2 V, occasionally to 55.3 V.

* What is your CV (bulk/absorb) voltage? That sounds like a CV voltage to me,  but it depends on your battery and the  CV voltage setting.

This patched firmware has a  new algorithm that has not been proven yet. It's only 10 or so lines of code, so I figured I'd be unlikely to  get it wrong, but it's certainly possible.

The voltage criterion is now that the battery voltage must strictly exceed (not merely equal)  the CV voltage  less 0.3 V (for  48 V models; 0.2 V for  24 V models). In other words, it must be at most 0.2 V below the CV  voltage setting for  30  seconds with no  exceptions to  get to the float stage. Does that sound reasonable?

It's possible that with your battery rarely seeing the  CV voltage, they might take longer than normal  to reach float for a few cycles.

* What chemistry is your battery?

 

My bulk is set to 57.6V, and 55.2 is exactly what is set as float voltage
My battery never goes even close to the CV for some reason
It did before on grid and even overshoot that voltage for a bit

My batteries are SOK LiFePO, BMS goes into OV at some voltage and starts balancing
Never happens on solar for some reason

Also, going to this firmware from 60.66 to 60.96 patched reintroduced the bug when inverter is using ~2A (~400W) from grid to charge the battery even is Only Solar Charging is selected

Edited October 24, 20241 yr by WallK

On 2024/10/23 at 8:37 AM, Tarek Yag said:

As you have DSP version 71.01 right now, it's totally logical that they pointed you to the 71.03 version, and from what I'm starting to believe right now, you need the 57.xx MCU firmware. Because these versions are what I found linked to each other in the official firmware folders available in the earlier shared FTP link.

Would you please confirm what's the original MCU firmware version that came with your inverter on purchase?

@Khalil Koja Would you please confirm what was the original DSP firmware version before any updates?

I think I just found out the firmware difference for "push button" and "touch button" models of VM III ??? @Coulomb

my original factory firmware is dsp: 71.01 mcu: 57.09
they did send me an ftp link that contained only the files I uploaded here.
I still haven't updated my firmware because the connecter on the old laptop I have, turned out to be VGA and not rs-232 🤣
since we both seem to be from that same country
where did you get the rs-232 to usb cable to update the firmware? I still can't find one to update my firmware.

Edited October 24, 20241 yr by Eddie1

12 hours ago, WallK said:

It did before on grid and even overshoot that voltage for a bit

My batteries are SOK LiFePO, BMS goes into OV at some voltage and starts balancing
Never happens on solar for some reason

From my experience, I guess this could be caused by a high charging current (40+ A). See, on grid you get the needed charging current right away, while on solar you'll get lower current over a few hours before you reach the day peak, where the batteries would be almost or already fully charged.

When charging so quickly, and without using a smart active balancer, it would be too late to balance all the cells quick enough, thus exceeding the over voltage limit with some cells. Try lowering your AC charger max current, I believe you'll get much better balancing near the end of charging, and won't go over voltage.

12 hours ago, WallK said:

My bulk is set to 57.6V, and 55.2 is exactly what is set as float voltage
My battery never goes even close to the CV for some reason

Would you please review your battery's specification sheet, or contact your seller and make sure what are the recommended charging settings for your battery? I do think there's something wrong with your voltage numbers and the battery is limiting the inverter from reaching CV stage because it's too high, thus staying near the float voltage.

12 hours ago, WallK said:

Also, going to this firmware from 60.66 to 60.96 patched reintroduced the bug when inverter is using ~2A (~400W) from grid to charge the battery even is Only Solar Charging is selected

Yeah, this is well known now. I believe it's just by design, where some firmware have it enabled, and some not.

2 hours ago, Eddie1 said:

my original factory firmware is dsp: 71.01 mcu: 57.09

That's what I thought. One last request please, would you please confirm what type of display buttons you have on your inverter? Push or touch buttons? A picture of the display only would be very much appreciated.

2 hours ago, Eddie1 said:

the connecter on the old laptop I have, turned out to be VGA and not rs-232 🤣

LOL. That's what I expected.

2 hours ago, Eddie1 said:

where did you get the rs-232 to usb cable to update the firmware?

You can find it at local PC stores/shops. It's a very old piece of tech, so no doubt you'll have to search a bit until you find it somewhere!

1 hour ago, Tarek Yag said:

That's what I thought. One last request please, would you please confirm what type of display buttons you have on your inverter? Push or touch buttons? A picture of the display only would be very much appreciated.

push buttons, brand: renovo, my inverter is exactly like the picture I uploaded before

On 2024/10/17 at 3:47 AM, Eddie1 said:

 

1 hour ago, Tarek Yag said:

You can find it at local PC stores/shops. It's a very old piece of tech, so no doubt you'll have to search a bit until you find it somewhere!

still searching for it, do you recommend some shop?

Okay, I just finished analyzing all FTP files and folders in the link that @Mohammad Jawish shared with us. Here are my findings summarized:

I've found firmware for many models, a lot named by folder name, but some are not named. Unfortunately for me, there aren't any folders named for VM IV whether twin or not. Anyway, I will focus on the named folders only.

Interesting models for this thread:

A. VM III (3 kW / 5 kW) Non-Twin
B. VM III (4 kW / 6kW) Twin

Other models:

C. Max (7.2 kW / 8kW)
D. Max E (11 kW Twin)
E. Max E (11kW Duplex)

The VM III models listed above come with the following DSP - MCU sets:

A : (DSP 47.03 - MCU 02.87) & (DSP 41.18 - MCU 02.90)
B : (DSP 60.10 - MCU 25.15) & (DSP 60.10 - MCU 57.16) & (DSP 71.03 - MCU 57.16)

In an overview of all available files at the shared link which is at the official Voltronic Power site. Although it's not a strict rule for them as we already know by experience, but I can now safely say that @Coulomb's general rule of following the same major version number for each DSP or MCU is totally correct. At this link at least, which is very recent, they look like they're using a single major version number for each major hardware version (or a customization).

Focusing again on firmware for the TWIN variants, and taking into consideration the recent findings the community is helping with. VM III Twin comes in two DSP hardware versions, and two MCU hardware versions, each have their respective firmware, and I can only guess that they can be mixed in production.

Finally, it's all speculations as all of this is not officially documented, but I wanted to put it out here for future reference, trying to understand the messy world of Axperts.

Edited October 25, 20241 yr by Tarek Yag

On 2024/09/14 at 1:36 PM, Khalil Koja said:

My MCU HAS NOT touch buttons and the buttons stop working after update from 57.08 to 25.08, I don't think that factory rest will solve this problem. I'm trying to get MCU FW 57.10 to test it.

21 minutes ago, Eddie1 said:

push buttons, brand: renovo, my inverter is exactly like the picture I uploaded before

Now, this at least proves my recent findings which I discussed in my previous post. You both had the same original MCU's major version number of 57.xx and you both have the push button display variant! @Khalil Koja I would really love to hear back from you after you reflash the recent MCU firmware I found for you a few posts earlier, hoping it solves your inverter's buttons issue!

4 hours ago, Tarek Yag said:

Try lowering your AC charger max current, I believe you'll get much better balancing near the end of charging, and won't go over voltage.

30A max for two 100A batteries in parallel is low enough I think (15A per battery)

 

4 hours ago, Tarek Yag said:

Would you please review your battery's specification sheet, or contact your seller and make sure what are the recommended charging settings for your battery? I do think there's something wrong with your voltage numbers and the battery is limiting the inverter from reaching CV stage because it's too high, thus staying near the float voltage.

It is literally the spec

And it happens only on solar charging

 

4 hours ago, Tarek Yag said:

I believe it's just by design, where some firmware have it enabled, and some not.

I don't think so, voltronic said it was a bug and provided me with 60.66 firmware built to fix it

On 2024/10/25 at 7:22 AM, WallK said:

30A max for two 100A batteries in parallel is low enough I think (15A per battery)

It is low enough indeed, as long as it's 0.5C (half the total capacity) you're on the safe side for sure.

On 2024/10/25 at 7:22 AM, WallK said:

It is literally the spec

I'm sorry to tell you this, but your settings are way above safe limits for LiFePO4 chemistry! Please search online for the recommended settings for a 48V LFP battery. I do prefer Andy's Off-Grid-Garage BMS settings (and I use them as-is for my JK-BMS), this guy is a genius! Check out his own settings at this link from his own website, or at least take some notes from the entire website, he has a great YouTube channel too, don't miss it.

I believe that you'll solve the whole issue when you use the recommended LFP battery settings.

On 2024/10/25 at 7:22 AM, WallK said:

I don't think so, voltronic said it was a bug and provided me with 60.66 firmware built to fix it

Thank you for this info! We hate their bugs for sure!!!

Edited October 27, 20241 yr by Tarek Yag

Here are more HEX File Only Packages of (DSP / Main CPU / U1) firmware for VM III TWIN and VM IV TWIN.

An updated list of available packages in this thread can be found in the very first post at:
https://powerforum.co.za/topic/29708-collection-of-dsp-axpert-firmware-for-vm-iii-twin-and-vm-iv-twin/

CREDITS: Original uploaders of the attached firmware files:

@Mohammad Jawish DSP version 60.10 dated 2024/06/14
Note: Quiet fans control logic is not available in this version + I copied this firmware's full package from the uploader's provided FTP link in his own post
Link to original package post

@Mohammad Jawish DSP version 71.03 dated 2024/03/12
Note: I copied this firmware's full package from the uploader's provided FTP link in his own post
Link to original package post

USE AT YOUR OWN RISK, NO GUARANTEES WHATSOEVER!

DSP Reflash Tool is always available in the very first post of this thread at:
https://powerforum.co.za/topic/29708-collection-of-dsp-axpert-firmware-for-vm-iii-twin-and-vm-iv-twin/

Detailed instructions of how to update/reflash firmware of Removable and Round Display inverter models, posted by @Coulomb at:
https://forums.aeva.asn.au/viewtopic.php?p=87767#p87767

If you think your inverter is bricked, there are a number of helpful tips posted by @Coulomb at:
https://forums.aeva.asn.au/viewtopic.php?p=59897#p59897

Enjoy!

VM TWIN (III & IV) DSP 60.10 hex.zip VM TWIN (III & IV) DSP 71.03 hex.zip

Edited October 27, 20241 yr by Tarek Yag

5 hours ago, Tarek Yag said:

Side note: you can't divide the current over your number of batteries when they're connected in parallel, they both take the same current equally in this setup.

Sorry, what? If I put 30A into system of two parallel batteries they each will take a part of it depending on their resistance
They will take fractions of available current, so that <full current> = <bat1 current> + <bat2 current>
So in my case of almost identical batteries one will take half and the other will have remaining half
Literally <available current> / <number of batteries>

 

5 hours ago, Tarek Yag said:

I'm sorry to tell you this, but your settings are way above safe limits for LiFePO4 chemistry! Please search online for the recommended settings for a 48V LFP battery. I do prefer Andy's Off-Grid-Garage BMS settings (and I use them as-is for my JK-BMS), this guy is a genius! Check out his own settings at this link from his own website, or at least take some notes from the entire website, he has a great YouTube channel too, don't miss it.

I don't have JK BMS and theirs charger settings will not allow the battery to ever balance
I will not change the BMS settings from designer's recommended (that we discussed with them) for the fear of losing a pretty long warranty
Also, those charging numbers are what BMS requests when connected over CAN or

 

5 hours ago, Tarek Yag said:

I believe that you'll solve the whole issue when you use the recommended LFP battery settings.

I've tried other settings and it's getting stuck at whatever is set as float

Edited October 27, 20241 yr by WallK

56 minutes ago, WallK said:

Sorry, what? If I put 30A into system of two parallel batteries they each will take a part of it depending on their resistance
They will take fractions of available current, so that <full current> = <bat1 current> + <bat2 current>

My bad, you're totally right, sorry for the misinformation! I deleted it in my previous post.

56 minutes ago, WallK said:

I don't have JK BMS and theirs charger settings will not allow the battery to ever balance

Sorry if I wasn't clear enough. The settings I shared do not exclusively apply to JK BMS, and I didn't assume that you have one, I just wanted to provide you with an example of good LFP battery settings.

56 minutes ago, WallK said:

I will not change the BMS settings from designer's recommended (that we discussed with them) for the fear of losing a pretty long warranty

The suggested settings you're given by your seller are way too high for an LFP, I confirm again. A 3.6 volt per cell is near the max limit of safe LFP voltage, and is a recommended "over voltage protection" setting for LFP! I just hope you never try their "Max Absorption Voltage" (3.65 VPC)!!!!

Anyway, if you're still not convinced and don't want to research, you better ask other battery experts about the values you got. I'm just trying to grab your attention for your own safety. I have no personal benefit out of this.

56 minutes ago, WallK said:

Also, those charging numbers are what BMS requests when connected over CAN

Any BMS when connected to an inverter will change charging settings of the inverter to what is set in the BMS settings, it's how the inverter - BMS communication works. Whatever battery settings you set in your inverter will get changed as soon as you connect your BMS successfully to the inverter.

Nevertheless, I will keep looking for a fix for that "not reaching CV stage" issue that I, you, and @bratpit have! I will mention you in any future findings in this regard!

Edited October 27, 20241 yr by Tarek Yag

3 hours ago, Tarek Yag said:

A 3.6 volt per cell is near the max limit of safe LFP voltage, and is a recommended "over voltage protection" setting for LFP!

This is exactly how balancing works
It goes into OV and then charges the cells that are under this
How else do you plan to actively top balance cells?

Your link recommend not charging to 100%, but most sources say it's fine or even recommended

And I'm not talking about seller here, I'm talking about battery designers here, Current Connected

 

3 hours ago, Tarek Yag said:

Nevertheless, I will keep looking for a fix for that "not reaching CV stage" issue that I, you, and @bratpit have! I will mention you in any future findings in this regard!

Just to reiterate -- this only happens on solar charging, grid charging is fine for some reason...

Edited October 27, 20241 yr by WallK

On 2024/10/24 at 8:02 PM, Tarek Yag said:

We didn't find the official full package of it,

I can confirm that my disassembly is in a folder called "dsp 60.76 hex only", and I don't have a complete upload archive.

 

On 2024/10/24 at 9:43 PM, WallK said:

My bulk is set to 57.6V, and 55.2 is exactly what is set as float voltage
My battery never goes even close to the CV for some reason

That's a very high voltage; an average of 3.60 V per cell. It's possible that the BMS will disconnect before it gets that high. I wonder if the inverter is struggling to reach that high of a voltage, though it's a common maximum for lead acid (14.4 V x 4).

There is no reason to go beyond 3.5 VPC; personally I stop my 16S LFP at 3.45 VPC, and float considerably lower.

4 hours ago, WallK said:

This is exactly how balancing works
It goes into OV and then charges the cells that are under this

That's how you equalise flooded lead acid batteries (and just add the dissociated water back afterwards). But with lithium chemistries including LFP, generally the excess charge of the highest  voltage cells are bled off with a resistor, or occasionally some capacitive or inductive circuit transfers charge from the highest voltage cells to the lowest voltage cells.

Having said all that, I can't see why the inverter won't get to 57.6 V.

Edited October 27, 20241 yr by Coulomb

8 hours ago, WallK said:

Just to reiterate -- this only happens on solar charging, grid charging is fine for some reason...

It happens on grid too.I checked it  at night.

At the begining  for example at 20% of SOC diode is blinking but goes early solid on . 

Edited October 27, 20241 yr by bratpit

4 hours ago, Coulomb said:

That's a very high voltage; an average of 3.60 V per cell. It's possible that the BMS will disconnect before it gets that high.

It should!

4 hours ago, Coulomb said:

But with lithium chemistries including LFP, generally the excess charge of the highest  voltage cells are bled off with a resistor, or occasionally some capacitive or inductive circuit transfers charge from the highest voltage cells to the lowest voltage cells.

As far as I've read it's balancing by using input current, not by discharging the highest cells (or something along the lines)
With the idea behind it being all the cells will become fully charged thus really balanced, not just equal voltage
I'm not sure about the specifics, but the disconnected battery with BMS doesn't balance, at least perceptibly
The highest cells just passively lose charge a bit faster. But this is an anecdote, I haven't left them for any substantial amount of time

2 hours ago, bratpit said:

It happens on grid too.I checked it  at night.

At the begining  for example at 20% of SOC diode is blinking but goes early solid on . 

I will check when I have good grid power if it goes over the float
But mine stops at 100% or close to it, it doesn't stop THAT early...

Edited October 27, 20241 yr by WallK

I have found the default (recommended?) settings of SOK 16S LFP if you're curious

This is actually the usual (or close to it) BMS config for Pace BMS based batteries, I have found several very similar setting by image search
But also some with 3.5 OV and 3.65 OVP
Not sure, but as said before -- I don't see a reason for it to affect inverter stopping at 55.2V

12 hours ago, WallK said:

This is exactly how balancing works
It goes into OV and then charges the cells that are under this
How else do you plan to actively top balance cells?

I think you have some BMS terminology misunderstanding. Over voltage is a dangerous voltage you never wanna reach. Balancing starts at a balancing voltage (not OV) and it's totally different for the two methods of balancing (passive and active) with the latter being the better and newer technology, and which all new BMS products are starting to adopt it.

12 hours ago, WallK said:

Your link recommend not charging to 100%, but most sources say it's fine or even recommended

100% SOC is something defined in your BMS settings, though not all BMSs give you the choice to change this.

12 hours ago, WallK said:

Just to reiterate -- this only happens on solar charging, grid charging is fine for some reason...

I have this happening on both charging sources! @bratpit

7 hours ago, Coulomb said:

That's a very high voltage; an average of 3.60 V per cell. It's possible that the BMS will disconnect before it gets that high.

That's exactly what I've been trying to say since the very beginning, thank you Coulomb for joining in, finally!

I have my BMS set at 3.5 for CV and 3.4 for float, but since I have the CV issue in my inverter, and my BMS comm is faulty and unable to connect to my inverter too, I got both on 3.5 V at the inverter level, I just hope to solve my problems soon enough to let my battery float, finally! Then, I'll even lower my CV to 3.450 and Float to 3.350, the best I've ever known!

Side note: Unfortunately, I'll be discussing replacing the BMS or the whole battery under warranty with my seller next week, as my BMS communication board proved to be faulty, finally!

Thanks for the rest of your explanation in your post, I always appreciate your advice.

3 hours ago, WallK said:

With the idea behind it being all the cells will become fully charged thus really balanced, not just equal voltage
I'm not sure about the specifics

Dear @WallK, I really appreciate you trying to understand how everything works, but I think you really need to consider my words, at least! Trust me, lower the voltages you have. To gain yourself some more LFP batteries knowledge, go check out the Voltage vs SOC curve for LFP, this chemistry is crazy near the two curve knees! You never wanna go near them, that's were voltage is not stable anymore and you will struggle with balancing, and of course it's the danger zone!

I'll end the discussion here because we went way too off-topic!

7 hours ago, Coulomb said:

Having said all that, I can't see why the inverter won't get to 57.6 V.

2 hours ago, WallK said:

Not sure, but as said before -- I don't see a reason for it to affect inverter stopping at 55.2V

I totally agree, and of course looking for a resolution for all of this!

Edited October 27, 20241 yr by Tarek Yag

@Tarek Yag @WallK @Coulomb @bratpit

I would like to share my experience as it could be beneficial , ,

My battery is : Felicity 48 200 10 kWh 

my inverter : Triple A Axpert VM III twin 

my battery/inverter reach 55.6 and stop charging, it never exceeds this voltage .

the inverter charge it till 55.6 then charging stops , the voltage dip slowly till it become 54.X (no floating ) then it charge it again to 55.6 (I don't know if its recharging due to normal voltage drop or because of balancing) it does this every 2 or 1 hour while there is a sunlight or grid .

7 minutes ago, esmail-kassir said:

(I don't know if its recharging due to normal voltage drop or because of balancing) it does this every 2 or 1 hour while there is a sunlight or grid .

If you have your inverter connected to your battery's BMS, this looks like the works of the BMS charging timers (for CV and Float), it's how BMSs normally operate. If this is the case, it is irrelevant to our issue.

1 hour ago, Tarek Yag said:

If you have your inverter connected to your battery's BMS, this looks like the works of the BMS charging timers (for CV and Float), it's how BMSs normally operate. If this is the case, it is irrelevant to our issue.

100% correct . it is connected 

I couldn't do many tests using manual settings because my inverter during charging and when the voltage exceed 55.X . inverter read much higher voltage than the battery , even it seems they are consistence in the other cases

Hmmm, could it be the CV timer in the BMS stopping the charging process? Solar charging is usually slower than AC charging, which might very well exceed the absorption timeout before getting the battery fully charged at first try

@WallK @Coulomb @bratpit ???

If this is the case, then the simplest solution would be increasing CV timeout, or decreasing Float timeout, or both to reasonable values!

Thank you @esmail-kassir for pointing this out!

Edited October 28, 20241 yr by Tarek Yag

 

4 hours ago, Tarek Yag said:

If you have your inverter connected to your battery's BMS, this looks like the works of the BMS charging timers (for CV and Float), it's how BMSs normally operate. If this is the case, it is irrelevant to our issue.

Mine inverter is not connected to bms. Both  BMS  and inverter are connected to SA.Inverter settings for battery is set tu "USER" 

Edited October 28, 20241 yr by bratpit

9 hours ago, bratpit said:

Mine inverter is not connected to bms.

Yeah, me too. So, this is not a possibility for you and me. I just wanted to make sure again that you have the exact same case as me. WallK has his inverter connected to the BMS, unlike us.