Hi,

I have two MPP 5048MG paralleled inverters (71.80) linked to 4.2KW of solar with 15.36KWH of battery (8 x Zenaji Aeon LTO), when I'm on battery the whole house runs off of it.

In summer, when I start to get multiple days completely on battery, I get power outages, basically for a few seconds the inverters seem to crap themselves and my power goes out and straight away it comes back up.  No errors that I know how to find.

Has anyone seen anything like that, it happened about a month ago (the last time I went over 24 hours on battery) and the power went early in the morning, ICC feeds into emonCMS and it showed a loss of data an hour before the outage (~50v on battery), then an hour later it pops back with data showing the battery at 0v and an hour after that the battery comes back at 50v, its really bizarre.

Its been happening in summer a lot since I got the system, it seems like maybe a CPU craps itself slowly and all hell breaks loose.

It doesn't happen at all in winter because I pretty much never get multiple days on battery, starts around November and stops around February.

I'm not really sure what I can do to troubleshoot it, I have a few UPS's now to mitigate some of the nastier effects but its still a pain, the living room TV coming on and the louvres opening at 6am is not great.

Cheers

Richard

I don't know what a MPP 5048MG is, maybe try figure out it's real name on the Voltronic web-site (the actual manufacturer of these inverters). I had my Axpert King 5kW do these recently when Cape Town had a high voltage cable fault that took out the whole City's power.  The inverter shutdown then turned back on after some seconds.   I suspect it was because there was a surge on the line, from pictures they released, it looks like there may have been a phase to phase short on two 100kV+ lines.  So I suspect a large imbalance followed by a voltage surge on one of the phases.  Point being, it may be that you have a surge.  And the reason it is probably during the summer is because you have the highest PV output during the summer.  So PV surge then maybe...

This is all speculation. @Coulomb is the guy to ask, he has a lot of experience with these, especially the PV side (which I don't use so have no experience)

Edited December 23, 20213 yr by Gnome

51 minutes ago, Gnome said:

I don't know what a MPP 5048MG is,

It's an Axpert MKS II 5K-48: high voltage SCC, older non-removable display, PF1.0, 5kW, 48 V nominal.

Quote

maybe try figure out it's real name on the Voltronic web-site 

I find it easier to use the Voltronic Zoo post.

Quote

@Coulomb is the guy to ask, he has a lot of experience with these, especially the PV side...

I have vastly less experience with the higher voltage SCC models. Whenever I hear of interruption of power like that, I suspect the battery BMS if disconnecting due to over-voltage. Richard has posted about his problem on the AEVA forum, which is why I didn't respond again here. Hopefully others that have this or a similar model can comment on their actual experience.

Richard's LTO battery (Lithium Titanite Oxide) is uncommon, but I suspect it's the same problem we see with many BMS: the manufacturer recommends a charge voltage that is very close to the cutoff voltage, and the Axpert overshoots the charge voltage, causing the battery to disconnect.