Erratic Battery State of Charge (SOC) levels
Hi,
I am quite a new user/owner of a Sunsynk system (just over 2 weeks). I think I have the hange of things but one that I am noticing that I don't really understand is that the State of Charge (SOC) for my batteries is changing quite a lot and it makes me worried that I might have either some faulty settings or faulty batteries.
I have seen three differnt things that worry me (as below), it would be great to understand if this is maybe normal for a new battery or if I should be worried.
I have a 3.6 kWh Hybrid Sunsynk invertor, 2 x 5.12 kWh Sunsynk CATL batteries and solar panels (all new).
Sudden drop in power I have had this happen once, but about 5 days ago the battery SOC went from 31% to 0% in 5 minutes (one reading to the next). I have only seen this once but from what I can see it genuinely needed charging to get back up.
SOC changing by up to 10% every 5 minutes/reading It comes and goes, but I notice that often when my battery is idle (i.e. I am not charging or drawing a load), the SOC will fluctuate constantly. I have had periods of 2 or more hours where almost every reading will go up as much as 12% and then back. i.e. at 1400 it will be 30%, then at 1405 back to 18%, then at 1410 back to 30%, and this fluctuation can go on for hours.
SOC jumping to 100% full and then dropping back again I thought to recently try charing the battery to 100% (I have read you shouldn't do this often), but I figured that might help improve the SOC reading. However I noticed that while charging, the battery from from 89% to 100% charged in 5 minutes (which is impossible...it should charge at 20% an hour)
It would be great if anyone out there has any advice. I have included some images of my set up below:
I had a similar problem with my 2xSSLB1 after it was first installed. This was tracked down to a faulty battery. The two were operating as masters despite one being set to slave. The inverter was then switching back and forth between the two for reporting purposes. I saw state of charge (SOC) levels jump up and down depending on which battery it was seeing. Further more the individual batteries started to drift out of sync, so the charge states leapt about even more, only getting back into sync after a charge level of 100%. After the faulty battery was replace they worked as designed and the SOC reading became as one and stable.
I wonder if you have a configuration or communication problem between your batteries and or inverter?