kosmik

I tried changing the battery settings from whatever to lithium etc but nothing worked you will still get SOC/V drift. Only way I overcame that is forcing a top up to 100%, and not the assumed SOC 100% but watch that it gets to that 53.77V mark. One installer did suggest going the setting by voltage route vs SOC which I suspect would work. Mine is set as per the Hubble recommended ( lithium and the respective levels ). The batteries have been fine since and I regularly use the system to the max of my inverter ( 5KVA ) and it has no problems with the batteries. You can clearly see where it misses a topup due to loadshedding and the next day it "regains" that lost voltage. If you want to run them, you either need the surety of one a week hitting the 53.77V or try the by voltage setting, otherwise you are going to have nasty surprises with SOC saying one thing and your actual battery voltage another and be left in the dark with a sudden shutdown because the batteries go into protection at 43.5V ( well, mine do ).

You might still need a bit depending but even if you do drop it is minuscule. On 40A charge, I get 32% SOC on 2 hours but if a bad day, thats still short of hitting the 53V float level. Because of winter and bad sun, the two day tiers I have is 70% and the 100% so that I can still capitalize on the sun but if its raining or badly cloudy, the time frame is short enough to still make it to float. Easy to reach the 70% from my nights usage ( Allowed 50% SOC ) and anything over the 70% odd gives the system time to float properly at full levels but the "100%" SOC is normally only around 52.4V odd so it needs a good few minutes to actually get the battery to the 53+ even at "100%".

100%. So what I've done now is have a forced timeslot to ensure that batteries hit 100% or at least do some balancing. I'm not too happy with how its tracking though as even with that, looks like I'm losing 0.3v a day ( drifting I should say ). Right now am on loadshedding but my SOC is 64% with a voltage of 48.09. Thats considering Monday it was at 100% for 40mins and yesterday for around 20mins ( 53.77V ) But lets see after a week, bad rain and cloud so a bit annoying and I have LS today during my topup time but that should be fine, will balance out tomorrow again, in theory so will see what happens then.

I agree with you Hendrik, I've had to now put in a schedule that ensures that the battery is at 100% at least at some point in the day. I'm not sure if that will work though as when I had it first installed, there was minimal battery soc and it would have hit 100% often. It is ridiculous though to have this "drift". So lets say a person gets a bad week of full rain and the batteries never hit 100%, mine are "crashing" between 7-14 days with charge/discharge between 40%SOC to 85% SOC. AM2's though.

So I had a crash again this morning but now I'm not sure if its the batteries or the inverter or as has been suggested the BMS. Would the BMS alter the state of the SOC vs its own? I would think not. To explain, the batteries dropped from 52% SOC to 0% SOC. Now looking at the batteries , they physically show 2 bars each ( assume 40% - 50% each ) so the battery LED SOC does not match the inverters soc. The inverter now thinks its charging from 0% even though the batteries show the two LED charge. Images below Battery 1 Battery 2 Inverter Ignore the time, its the 1 hour ahead issue, this was at 6.48 this morning. Currently charging as if from zero. Oh and no faults visible anywhere. Kicked it up to my installer as well to see what the hell is going on. If the serial number is anything to go by, these batteries were manufactured in Feb this year so should be on the latest firmware etc I'd assume but I'm now thinking its either the inverter or something with the canbus between them?

I could understand that but previously it was hitting 100% daily and I still had the failure at @ 90% that time. Admittedly since the change I don't think I've hit 100% with the rain and cloud at the moment but there is a mandatory topup to 85% regardless late afternoon.

I have the same/similar problem. My battery voltage "creeps" lower and lower even though there is the same SOC at times. Monday last week was my "crash" @ 46% SOC. Previously I had one @ 92% SOC and they altered some settings but if I go back, the same slow voltage decay happens over time. For example, All at SOC 60% - Static 15 May - 46.3V 14 May - 46.8V 13 May - 47.1 V 12 May - 47.3V 11 May - 47.6V 10 May - 47.9V 9 May - 48.5V 8 May - 46.0V ( Day of last "crash" , just before )