weber

Interesting update. Thanks Calvin. No, I didn't take him up on the offer to send me some cells, as we already had the charge/discharge curves from Arvio (that showed they were LTO) and I couldn't do any chemical or microscopic analysis. It's interesting that they now admit they are LTO. But I expect they are still poorly-manufactured LTOs and I expect their BMS will still be rubbish.
I'm sorry I have no additional evidence.

Anyone thinking they might take a risk on these so-called "super-capacitors" on the basis that LTO is a long-lived battery chemistry, should forget it. That's only the case if the LTOs are properly manufactured and are protected and balanced by a proper BMS. The BMS in this device is rubbish. The photos of the fire should have been enough to convince us of that. But some more information has recently come to light, thanks to a brave volunteer guinea-pig.
I received the following email 6 weeks ago. I asked the author to please post the information himself directly, but because he hasn't yet done so, and I'm concerned that people might still be thinking it's worth the risk, I post the email below, unedited. "Arvio" is the Australian agent for these devices.
The executive summary: It lasted about 2 years. The warranty was not honoured. Disassembly found bulging cells and leaking electrolyte.

 

Users of Coulomb and Weber's patched firmware 72.00a beta for the Axpert King 1 or PIP-MK, please note: The rarely-used feature "Dynamic Current Control" does not work with solar charging. It only works with AC charging. The SCC continues to use the EEPROM value of maximum charge current. I have updated the documentation accordingly.
Many thanks to @Calvin, for reporting this. Thanks also to Calvin for reporting that all other features work as advertised in his 3-parallel-machines setup, as we did not have parallel Kings for testing.

This is no longer strictly correct.  I have 3 Kings in parallel and the Dynamic Charge Control not only does not work but causes wrong data - I reported the symptoms to @Coulomb some time ago.
Having said that, all the other features work very well, exactly as advertised.  Great improvement over the normal firmware.
 

I just noticed that we never announced in this thread, the September 2023 release of our fully patched firmware for the Axpert King, kindly sponsored by Power Forum member @Youda. See https://forums.aeva.asn.au/viewtopic.php?p=97712#p97712
It says "beta", but it's thoroughly tested by now and no problems have been reported.
[Edit: Calvin has since reported that Dynamic Current Control does not work with solar charging in this beta patched firmware. It only works with AC charging. The SCC continues to use the EEPROM value of maximum charge current. Calvin reports that all other features work as advertised in his 3-parallel-machines setup.]

I assume
I assume you're happy that the upper limits on all 5 user voltage settings are not too restrictive for 18S LFP. They look OK to me. There are 3 hidden voltage settings that can't be changed by the user. We have set them based on 15S and 16S in the LFP flavour of our patched firmware. But they will probably be OK for 17S and 18S too. You can read about them here:
https://forums.aeva.asn.au/viewtopic.php?f=64&t=5955&p=76194#LFP
Time, indeed, is the real issue. The electrolytic capacitors on both the battery bus and the 400 V bus will age more rapidly because they will be running closer to their rated voltages. They will spend most of their time around 60 V instead of 53 V. It's almost certain that these inverters were not designed with that in mind. These capacitors, particularly those on the battery bus, have always been a weak point of these inverters. And when their internal resistance rises enough that they can't control the voltage spikes that the MOSFETs are subjected to, the MOSFETs will also be 7 V closer to their rated voltage.

We have already released patched firmware for the King which fixes the premature float bug (and nothing else). That's presumably what Lionel is referring to below. It can be found here:
https://forums.aeva.asn.au/viewtopic.php?p=76178#p76178
I assume you meant to write "PIP-5048MK". Yes, Coulomb recently obtained one, and we plan to start porting more of our PIP-5048MS patches to it in a few weeks time.

We have already released patched firmware for the King which fixes the premature float bug (and nothing else). That's presumably what Lionel is referring to below. It can be found here:
https://forums.aeva.asn.au/viewtopic.php?p=76178#p76178
I assume you meant to write "PIP-5048MK". Yes, Coulomb recently obtained one, and we plan to start porting more of our PIP-5048MS patches to it in a few weeks time.

Anyone thinking they might take a risk on these so-called "super-capacitors" on the basis that LTO is a long-lived battery chemistry, should forget it. That's only the case if the LTOs are properly manufactured and are protected and balanced by a proper BMS. The BMS in this device is rubbish. The photos of the fire should have been enough to convince us of that. But some more information has recently come to light, thanks to a brave volunteer guinea-pig.
I received the following email 6 weeks ago. I asked the author to please post the information himself directly, but because he hasn't yet done so, and I'm concerned that people might still be thinking it's worth the risk, I post the email below, unedited. "Arvio" is the Australian agent for these devices.
The executive summary: It lasted about 2 years. The warranty was not honoured. Disassembly found bulging cells and leaking electrolyte.

 

Anyone thinking they might take a risk on these so-called "super-capacitors" on the basis that LTO is a long-lived battery chemistry, should forget it. That's only the case if the LTOs are properly manufactured and are protected and balanced by a proper BMS. The BMS in this device is rubbish. The photos of the fire should have been enough to convince us of that. But some more information has recently come to light, thanks to a brave volunteer guinea-pig.
I received the following email 6 weeks ago. I asked the author to please post the information himself directly, but because he hasn't yet done so, and I'm concerned that people might still be thinking it's worth the risk, I post the email below, unedited. "Arvio" is the Australian agent for these devices.
The executive summary: It lasted about 2 years. The warranty was not honoured. Disassembly found bulging cells and leaking electrolyte.

 

Anyone thinking they might take a risk on these so-called "super-capacitors" on the basis that LTO is a long-lived battery chemistry, should forget it. That's only the case if the LTOs are properly manufactured and are protected and balanced by a proper BMS. The BMS in this device is rubbish. The photos of the fire should have been enough to convince us of that. But some more information has recently come to light, thanks to a brave volunteer guinea-pig.
I received the following email 6 weeks ago. I asked the author to please post the information himself directly, but because he hasn't yet done so, and I'm concerned that people might still be thinking it's worth the risk, I post the email below, unedited. "Arvio" is the Australian agent for these devices.
The executive summary: It lasted about 2 years. The warranty was not honoured. Disassembly found bulging cells and leaking electrolyte.

 

I'm sorry @Hercules Weyers, but you appear delusional when you claim:
(a) there was no over-current protection (thanks @plonkster), and
(b) there was no fire—only a DC arc.

You also imply that the owner is certifiably insane, by claiming they had the system redone "using exactly the same modules". Can you provide any evidence for this? Or for any other of your claims that weren't already disproved by the available evidence before you made them?

The Sirius supercapacitor scam just hit Australia. I was looking for info and found that you guys had it 18 months ago. See my posts on the Australian Electric Vehicle Association forum.
http://forums.aeva.asn.au/viewtopic.php?p=66819#p66819

@David Botha  The advice you received above is sound and valuable. I have been using ICC-Pi since it became avaliable and the  control and monitoring of your solar system is just too good to not install it. I have also flashed my 2 Axperts with @Coulomb and @weber's much improved firmware. Also flashed my Internet router with Gargoyle free firmware which has OpenVPN built in. As @wolfandy said, you can control your setup remotely and with the router VPN,  safely from anywhere in the world via the Internet. All these benefits are just too important to ignore. Besides it is a lot of fun too. 

Weber and I are considering a fully patched Axpert King (PIP-5048MK) firmware at some point. But this is a lot of work, and it would have to be community tested, since we don't have Kings to work with or test on. With the rapid change in King main (DSP) firmware, we don't want to start this, only to have it obsoleted, and/or have to do it all again to a new version.
So we want to wait till the worst of the bugs we don't know how to fix (such as PV dips and freezes) are fixed, and there isn't a new version every few weeks to cater for new battery models with BMS. Forum readers will be in the best position to judge when the firmware is stable. Is 71.92 this stable version yet? Is 71.93 better?
For example: I've not heard much about the PV dips and freezes lately. Is that because it's fixed? If so, does anyone know what version it was fixed in?

See Coulomb's excellent posts via the first 3 links here:
https://forums.aeva.asn.au/viewtopic.php?t=4332#commands

There is no patched firmware for any 3 kVA models.

This is not mere theory. Coulomb and I do this with every new battery (set of cells). The typical 55 W headlight bulb draws about 4 A at 13.8 V, so you might expect it would only draw a quarter of the current at a quarter of the voltage, so about 1 A at 3.4 V. But in fact it will draw about 2 A at 3.4 A. This is because the filament has a much lower resistance when it is only glowing a dull red compared to when it is white hot.
A fan will behave in the opposite way. i.e. it will draw much less than a quarter of the current at a quarter of the voltage. I doubt that the fan will draw enough current from a single cell to be useful in balancing the cells in a reasonable time. But it can't hurt to try it.
If you only do this manual balancing after you stop charging, then the cell you connect the load to, and in fact all the cells, will drop below 3.4 V almost immediately, so you will only have a very short time of balancing. You would have to repeat this many many times.

This is not mere theory. Coulomb and I do this with every new battery (set of cells). The typical 55 W headlight bulb draws about 4 A at 13.8 V, so you might expect it would only draw a quarter of the current at a quarter of the voltage, so about 1 A at 3.4 V. But in fact it will draw about 2 A at 3.4 A. This is because the filament has a much lower resistance when it is only glowing a dull red compared to when it is white hot.
A fan will behave in the opposite way. i.e. it will draw much less than a quarter of the current at a quarter of the voltage. I doubt that the fan will draw enough current from a single cell to be useful in balancing the cells in a reasonable time. But it can't hurt to try it.
If you only do this manual balancing after you stop charging, then the cell you connect the load to, and in fact all the cells, will drop below 3.4 V almost immediately, so you will only have a very short time of balancing. You would have to repeat this many many times.

One way is to use one or more car headlight bulbs with alligator-clip leads, and a multimeter. With the battery on charge, and close to full charge, clip the bulb(s) on to the cell(s) with the highest voltage(s), provided that voltage is greater than 3.4 V (for LFP cells), to burn off some charge and let the other cells catch up. You can leave the bulb on a cell until its voltage drops below that of the lowest voltage cell.
You can also work in the other direction. If you have an adjustable-voltage current-limited power supply (a lab power supply) you can set it to 3.6 V, and when the whole battery is being charged and some cells are over 3.4 V, connect it to the lowest voltage cell until it goes above the voltage of the highest voltage cell.
If there happens to be two to four high cells next to each other, you can clip one bulb across the lot to burn off charge faster.
You should put each bulb in a porcelain cup or mug to stop it blinding you and melting things. This is a @Coulomb innovation. 😀
Likewise if you have a number of low cells next to each other, you can adjust the lab power supply to (n × 3.4 V) + 0.2 V. But this is more dangerous. You must monitor the individual cells often to ensure none goes over 3.6 V.
3.4 V is an absolute minimum for balancing. The higher you go, the more accurate the balancing will be, but you shouldn't let any cell go over 3.6 V.
I note that connecting LFP cells in parallel will not balance them unless you charge them to more than 3.4 V while they are connected in parallel.

The best hypothesis I can come up with is that the battery was sitting on the shelf for a while before it got to you. And in that time the cells got out of balance by maybe 2%, so that when the battery voltage gets to 27.6 V you have 7 cells averaging 3.41 V each and one cell at 3.73 V. The BMS would have switched on the bypass resistor for that cell when it passed about 3.5 V, but it can only bypass maybe 1 A, and you're charging at maybe 30 A, which is why it got up to 3.73 V. And then to save that one cell, the BMS open-circuits the whole battery using a solid-state relay so the charge current goes to zero. That's what I think is happening when the voltage suddenly jumps up to the absorb voltage setting of 28.4 V.
After a few minutes of disconnection, the bypass resistor pulls the voltage of that cell below maybe 3.6 V and the BMS reconnects the battery, and the cycle repeats. As it's doing this, the high cell is coming more into balance. But if it was 2% ahead of the others, that's 4 Ah for a 200 Ah battery. And if the bypass is only 1 A, then it will take 4 hours to balance that out. So it may continue these crazy oscillations for several (sunny) days, but if I'm right, they will eventually reduce and finally cease.
If you want to speed the process up a little, and be a little kinder to the battery, you could wait until the problem starts occurring each day, then set the max charge current [02] down to its minimum of 10 A, and then set it back to 30 A or 40 A each evening. But you don't need to do that. You can just let it go as it is now.
Please let us know how it is going in say a week's time.

It's only on cloudy days that it might matter. You can wait and see if you get premature float on cloudy days, and if so, drop setting 02 to 30 A.

Today I updated my September 2018 King firmware from 71.50 to 71.86. I also updated the screen firmware to 2.00. The updates went well and took about 15 minutes to complete.
After changing setting 5 to PYL and waiting about a minute. I now have communication between the batteries and the inverter. So it seems (for my inverter anyway) the 2018 Kings do have the correct hardware to communicate with Pylontech batteries.
  
 

Coulomb and I have just uploaded a beta version of our first patched firmware for the Axpert King, based on 71.80. It is called 71.80d and it only fixes the premature float bugs. It does not fix the PV dropouts or freezes. It does not add any of our features such as AussieView, KettleKomp or Dynamic Current and Load Control. You will find it here:
http://forums.aeva.asn.au/viewtopic.php?f=64&t=5955&p=76178#p76178

Coulomb and I have just uploaded a beta version of our first patched firmware for the Axpert King, based on 71.80. It is called 71.80d and it only fixes the premature float bugs. It does not fix the PV dropouts or freezes. It does not add any of our features such as AussieView, KettleKomp or Dynamic Current and Load Control. You will find it here:
http://forums.aeva.asn.au/viewtopic.php?f=64&t=5955&p=76178#p76178