McKracken

Update - After getting hold of Solar Assistant and the right cables to see the data from the battery BMS it turned out that the BMS was reporting a decreased capacity by over 12% on each battery. The cycle counter was at 94 and 89 on the 2 batteries. They are 100Ah units. To read the BMS data I had to run the inverter on USE (user) battery settings as the comms don't work to Solar Assistant and the inverter at the same time. I started by using the sticker values for the battery settings and found that when the BMS reported 5% SOC it ran like that for a long time, much more than it should have, then after charging up the battery the BMS reported it's capacity had returned to 98%. I tested each battery one at a time and they both behaved the same. It looks like there is a bit of a quirk in the BMS capacity calculation. Once the battery was charged the capacity dropped but the charge stayed constant resulting in over 100% charge, so it seems the BMS is reducing the capacity number which was giving me a larger loss than expected based on the SOC reported by the inverter when communicating with the BMS. I am going to look into updating the battery firmware in the meantime. At the moment I am running the battery on user settings, but have matched what the KOD (Kodak) values were as they auto populated the parameters. Here are some screenshots for those interested After a full discharge and during charging capacity increased from 89 to 95.9% After charging the same battery it showed 97.9% and I let it sit overnight, the BMS reported capacity dropped to 88.9Ah but the charge didn't:

Its a 2kW element which the inverter reported as running at 2.16 to 2.17 kW, I assumed 2.17 for the entire duration, it ran continuously as the geyser was cold at the beginning, and the data from the app confirmed it ran non stop for the 3 hrs exactly.

Just for the record, Mako and I are talking about the same installation. When using the 'Kod' (Kodak) settings in parameter 5 the SoC displays matches the batteries LED indicators. The problem comes after a night of running on battery power, the SoC has dropped significantly more than expected. I ran a test with only a geyser element running for 3 hours, and the batteries lost 7.4752kWh, while the geyser consumed 6.51 kWh- a difference of 962Wh The inverter won't be drawing 320W and all the other breakers were tripped the USE settings are being run with the battery sticker values at the moment as an alternative (but the SoC is more or less meaningless) it would seem that the USE settings are utilising more of the battery capacity, however the Battery LEDs are still showing lower than they should after a night.