The (no longer) Latest Patched Firmware Description
Update: See the Firmware section of the index post
to find the latest patched firmware for your machine.
LiFePO₄ and Lead Acid Patched Firmware
This post describes both the LiFePO₄ and Lead Acid patched firmware for PIP-4048MS, Axpert 5 KVA and similar machines with other names. It is based on Voltronic's 72.60 firmware, which is supplied with newer machines that have single, dual or triple MPPTs (Solar Charge Controllers) that are capable of charging at up to 80 A. We believe that it is safe to use on all post-2013 machines.
and disclaimer. It is possible to set the total charge current to 140 A, which may be beyond the capacity of your hardware. I don't believe that this is a problem, since the Solar Charge Controller (SCC) will limit itself to its own hardware capacity. All our testing has been on an early 2016 machine which came with 72.40 firmware, and no adverse effects have been detected to date, apart from the 60 A current limit noted below in the section headed "SCC Compatibility". So it all should be safe, but caution is advised particularly during initial testing.
This patched firmware has been developed mainly to overcome a bug in the charging algorithm for these machines. The bug manifests itself as not charging the battery fully. When charging from solar, the charge will often transition from bulk/absorb mode to float mode far too early, often in the first minutes of charging. The reason is that one of the termination conditions is the current dropping off to a low value. This is all well and good, but there is no check that the low current is due to the charge having completed; it could happen because the solar charge current available is below that low value. Our patch introduces an additional termination criterion: the battery voltage must be near the bulk/absorb voltage setting (parameter 26 on the LCD menu) as well as the charge current being at the low value. This means that the absorb stage cannot complete until the battery is close to or above the required absorb voltage. This bug is more likely to be seen when the maximum charge current setting is high; as a result, it seems to be less commonly seen with lead acid batteries (which typically charge at C/10 to C/6.7).
For those interested in the exact new charge terminating conditions, here they are. Others can skip this somewhat complex paragraph. The battery voltage must stay above a threshold, and the charge current must stay below another threshold, for at least 50 seconds. The voltage threshold is the bulk/absorb setting (parameter 26) minus 0.5 V. The current threshold is the maximum of two values:
1) the sum of all the Maximum Charge Current settings (parameter 02) for all paralleled machines, divided by 5 (24 for LiFePO₄), and
2) the number of paralleled machines multiplied by 5 amps (1 amp for LiFePO₄).
The official firmware is the same except that (a) it doesn't have the voltage criterion, (b) the total of maximum current settings is always divided by five, and (c) the number of paralleled machines is always multiplied by five amps.
Having gone to the trouble of devising the patched firmware, some other changes became desirable. Some of the 7 segment character renderings leave something to be desired, particularly letters "r" and "k". Weber devised a set based on what others have done, and a desire to have most character renderings distinct. In the end, he decided that "S" and "5" need to use the same rendering. Some letters like "M", "W", "X" and "k" you can't do much with, but I think he's chosen good compromises.
When more than one machine is parallelled, one is designated the master, with "HS". This was presumably because they thought their rendering of an H looked more like an actual M than their rendering of an M did. In this firmware, we've used a different rendering of an M. After a while, you get used to reading the three separated segments as an M. Try to imagine it's like this:
It's also desirable that the patched firmware be readily identified, yet software such as Watchpower should not be confused by a version it's never heard of. Therefore, the U1 main version display screen has been replaced with either an Li1 (lithium iron) or Pb1 (lead acid) display screen, still with 72 in the middle, but now with 60A on the right. Subsequent versions of the patch will be labelled 60b, 60C and so on. Enquiries such as QFVW (main firmware version enquiry) still return 00072.60 as before, so that Watchpower still works properly (with the limitations described at the end of the following post).
LiFePO₄ patched firmware only
All changes from here on are made to the Lithium Iron Phosphate (LiFePO₄) version of the patched firmware only. For other common lithium chemistries the "lead acid" patched firmware should used, typically with 14 cells in series.
For LiFePO₄ batteries, the most important other desired change is the battery low cutoff voltage, where the battery will be effectively disconnected to protect it from under-voltage. The maximum that this voltage can be set to in the official firmware is 48.0 V, which is unsuitable for lithium iron phosphate batteries. We have added 4.0 V to the manufacturer's range of 40.0 to 48.0 V, allowing cutoff voltages of 44.0 to 52.0 V. This assumes 16 cells in series.
In cases where the battery low cutoff voltage defaulted to 42 V, it now defaults to 44 V.
The battery low warning used to happen at 2 V above the battery low cutoff voltage, and reset at 4 V above the battery low cutoff voltage. They now happen at 0.5 V and 1 V above.
The transition from the "float" charging stage to the "bulk" charging stage was set at 4 V below the float setting. This has been reduced to 1 V below.
It also makes sense for parameter 12 (back to utility voltage) to be increased. This is the battery voltage below which the loads will switch back to the utility. This is used when output source priority (parameter 01) is set to Sbu or SoL. Now, the range of this setting has been increased by 2 V, so it is now 46 V to 53 V.
LiFePO₄ and Lead Acid Patched Firmware
* The extra criterion for transitioning from bulk/absorb to float.
* "Font" improvements, and HS -> MS for Master units.
* Firmware revision display screen contains patch revision.
LiFePO₄ patched firmware only
* The bulk/absorb to float transition occurs with a different threshold: minimum 1 A per paralleled unit, and (sum of maximum charge current settings) divided by 24.
* Low battery cutoff voltage range changed from 40-48 V to 44-52 V.
* Back to utility voltage range changed from 44-51 V to 46-53 V.
* Float to bulk charge stage transition occurs at 1 V under the float setting.
* The battery low warning occurs at the cutoff voltage plus half a volt, and returns at cutoff plus one volt.
SCC firmware compatibility
The Voltronic main firmware version 72.60 normally coexists with SCC firmware version 04.10. If you use either the original 72.60 or our patched 72.60A with any earlier version of the SCC firmware, the inverter refuses to charge from solar unless you set the maximum total charge current (parameter 02) to 60 A or lower.
So if you need a higher maximum charge current and you want to use this patched firmware, you will also need to update the SCC firmware to version 04.10 (provided below).