coulomb wrote: ↑Mon, 13 Aug 2018, 22:19
... I note that the MS
E series, being "economy" models, aren't parallelable. So they should not have the major charge bug, which is in a function associated with parallel operation. In fact, I believe that the source file name with the main charge bug is "parallel.c".
Despite asking Coulomb to explain this in email, I still have no idea why he thinks that the function containing the bug is "associated with parallel operation" in such a way as to suggest that it would not be present in a non-parallelable machine. The function is only associated with parallel operation in the weak sense that almost
every function needs to consider other machines in parallel, when they can exist. The bug itself is not associated with parallel operation in any way.
The bug is in the function that checks whether the conditions have been met to go from absorb stage to float stage. This is required whether machines are parallelable or not. As Coulomb discovered, the bug consists in choosing the
smaller of the absorb and float voltage settings when it should be choosing the
larger. The cause was probably a programmer typing a "<" instead of a ">".
The MSE and MS series are so similar in every respect
apart from parallelability, that I think it is almost certain they use the same code-base. I think the parallel version of that function was almost certainly created by copying a non-parallel version and modifying it. But there was no reason to revisit the buggy comparison in that process, as this only involves voltage settings, and voltage settings are necessarily the same across all machines in parallel. Other functions take care of that.
So I think it is highly likely that the MSE series have the same premature-float bug as the MS. But there is no need to rely on either Coulomb's theory or mine. If you have one, you can just do the experiment I describe here:
viewtopic.php?title=pip4048ms-inverter& ... 332#p59896
The good news is that Coulomb and I have weakened.

We will look at fixing the premature float bugs (only), in any model closely related to the PIP-4048MS (off-grid, not grid-feed or hybrid) [Edit: and not those models with unsafe SCCs (those that can't go below 120 V and have no insulation monitoring)], if someone can send us a firmware update file for it, e.g. by forum private message. We will keep such benefactors anonymous.
One of the fathers of MeXy the electric MX-5, along with Coulomb and Newton (Jeff Owen).