Hey all, I have 2 Axpert 5000 inverters working in tandem.  Then I have 3x 2.4kWH Pylontechs and 1x 3.5kWH Pylontech.  Been running for around 4 years all-in-all, although the 3rd 2.4 battery was purchased mid 2021 and the 3.5 was bought about a year ago (end 2022).

Charge during the day on sun, plus, if needed, eskom will supply house load, so that full, final few hours of solar can top-up batteries at the end of the day.  Mostly batteries are full by 12:00 - 13:00, but some days not, then after 3, eskom will take house load to let solar tup up batteries.

For the night we use the batteries, and can get through a night usually.  Some nights, when batteries don't look like they'll make sunshine, the system brings eskom back into play again to take on the house load and spare the batteries for sunrise.

As a general rule, we nev er charge batteries from eskom - only solar.  Eskom mostly only takes the house load when batteries need some extra juice from solar to be ready for the night.

Obviously, one or two rainy/cloudy days in sequence, I will usually let eskom run all loads, and then, with exception, let eskom also charge batteries incase loadshedding or transformer failure due to so much rain (REFERRING TO ESKOM TRANSFORMER - think WAPADRAND!)  🙂

So, all has been running well for a long time, but, recently I say an H4 warning on both inverters, and checked to see that it means battery voltage low (49v).  This is when batteries are charged way above 60% and even higher, to 80%.

Does anyone know what I could be doing wrong, or what setting is leading to this?  For about three years prior, I never had this.  The only change to the system is that I switched from ICC (SMH) to Solarassistant.io  I find the latter WAY more useable and "intelligent".  With SMH, I had to be on it like white on rice!  Checking the system and what was going on roughly 4 to 5 times per day to make sure things were running in such a way that we always had power.  With SA.io, it has enough intelligent programbility that I hardly ever even think about our solar anymore.  I love this software!  It has changed my life!  But, maybe I have a setting wrong, or I am using charging/batteries wrong, or such, so any assistance would be highly appreciated.

Cheers all

I'm sure folk with more experience of your particular setup will be along shortly, but to get you started...

Does solar-assist log the battery voltage?  Can you see if the 'low voltage' event coincides with anything, like a heavy load?

Personally, I'd start by running the system at a moderate/high load for 20 mins or so and check that nothing on the battery side is getting hot - connections, breakers, busbars etc.  A loose connection or faulty breaker can cause 'low voltage' alarms under load, but seem fine otherwise - but rapidly get worse.  Best to start with the basics.

Next step would probably be to get yourself a USB->RS232 cable (with appropriate connectors) and a copy of the Pylontech 'BatteryView' software to interrogate the batteries.  They hold a lot of detailed information regarding which battery did what and when.  If it is an issue with one (or more) of the batteries, it should tell you.

Can you maybe say a bit about how the system is wired?  Single stack?  Are the batteries (data) linked?