CTskollie Posted July 9 Share Posted July 9 Good Day All, I just need some assistance to confirm all my settings are correct, I set my SOC to a minimum of 20%, i noticed this morning however my battery dropped to 0%. I also noticed some weird spikes in the battery percentages on some days but never thought anything of it, I set my SOC to a minimum of 20% with no grid charging. Am i missing a setting that my battery is dropping below this level? I thought the battery would hold at 20% until there is enough solar to charge it up again but won't drop below the minimum SOC. I changed the setting to grid charge now and the battery is charging normally now but just want to check if I am missing something here. Battery went from 20 normally down to 17 and then just down all the way to zero. Should i request a firmware update perhaps? Inverter is a Sunsynk 8kw and BSL7kw battery. Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 Battery had less than 20w power draw Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted July 9 Share Posted July 9 12 minutes ago, CTskollie said: Battery had less than 20w power draw This seems pretty normal if the BMS disconnects at 20%. Even if the load is 20W. Then after the BMS disconnected it bounced back to normal after reconnecting. Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 (edited) Agreed that it is normal, I cannot however see with no load why the battery dropped below 20% and then a massive dip from 17% straight to 0%. With my minimum SOC of 20% should the battery not hold at that level and use grid when battery reaches that level and not allow it to drop further. Edited July 9 by CTskollie Quote Link to comment Share on other sites More sharing options...
Shadders Posted July 9 Share Posted July 9 2 hours ago, CTskollie said: massive dip from 17% straight to 0% I often see big changes in SOC when the BMS encounters a fault such as a single cell under voltage. How old is the battery? Numerous battery manufacturers recommend a full discharge and recharge cycle to calibrate the SOC reading on installation. It could be that your battery hasn't had the chance to do this yet and so the SOC was out of whack. Other thing to watch out for is that the inverter might have lost coms with the battery and defaulted to the voltage control settings. BMS_Err_stop isn't checked so the system won't shutdown or show the error pop up. Quote Link to comment Share on other sites More sharing options...
Shadders Posted July 9 Share Posted July 9 2 hours ago, CTskollie said: With my minimum SOC of 20% should the battery not hold at that level and use grid when battery reaches that level and not allow it to drop further. Yes it should do that, was grid available? Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 6 minutes ago, Shadders said: I often see big changes in SOC when the BMS encounters a fault such as a single cell under voltage. How old is the battery? Numerous battery manufacturers recommend a full discharge and recharge cycle to calibrate the SOC reading on installation. It could be that your battery hasn't had the chance to do this yet and so the SOC was out of whack. Other thing to watch out for is that the inverter might have lost coms with the battery and defaulted to the voltage control settings. BMS_Err_stop isn't checked so the system won't shutdown or show the error pop up. Battery is about 4 months old now, done a full recharge this past Saturday as battery is currently only set to charge from PV. Should the BMS_Err_stop be checked? Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 5 minutes ago, Shadders said: Yes it should do that, was grid available? Grid was available yes and was running off from the grid during that period. Would it still deplete the battery with the grid being available below the minimum SOC? Quote Link to comment Share on other sites More sharing options...
Bobster. Posted July 9 Share Posted July 9 Two things 1) what is your grid voltage like? My system is set to stop using battery at 40% SOC and resort to grid (so that I always have some battery in case of an outage), but one day whilst the grid was up, it went past 40 to about 35. Shouldn't happen! But the incoming grid voltage was low, the inverter had disconnected and as far as it was concerned it was running off grid and now could start using the reserved charge in the battery. 2) at what SOC does your battery shut itself down to protect itself? Mine will shut down, irresepective of any settings on the inverter, at 10%. At which time the inverter will see zero % SOC because the battery is shut down and will not be sending any information to the inverter. Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 21 minutes ago, Bobster. said: Two things 1) what is your grid voltage like? My system is set to stop using battery at 40% SOC and resort to grid (so that I always have some battery in case of an outage), but one day whilst the grid was up, it went past 40 to about 35. Shouldn't happen! But the incoming grid voltage was low, the inverter had disconnected and as far as it was concerned it was running off grid and now could start using the reserved charge in the battery. 2) at what SOC does your battery shut itself down to protect itself? Mine will shut down, irresepective of any settings on the inverter, at 10%. At which time the inverter will see zero % SOC because the battery is shut down and will not be sending any information to the inverter. How would I check my grid voltage, last I suspected a faulty breaker i checked and the mains was 230v but not sure if it can be monitored in real time. Shut down I set at 20%. Quote Link to comment Share on other sites More sharing options...
zivva Posted July 9 Share Posted July 9 You would need to access the BMS software to check its settings : at what cell voltage it is supposed to reach low voltage disconnect. And try again to discharge your battery to 20% and check what is the voltage of the lowest cell. Then you will know how far you can go before BMS shuts down ... As for BMS_err_stop setting, you can leave it unchecked. It would stop using the battery and display an alarm if communication stops between the BMS and inverter. Not related to your problem ... Quote Link to comment Share on other sites More sharing options...
Bobster. Posted July 9 Share Posted July 9 (edited) 41 minutes ago, CTskollie said: How would I check my grid voltage, last I suspected a faulty breaker i checked and the mains was 230v but not sure if it can be monitored in real time. Well it can be. I presume there is monitoring equipment available that will do it. But I had various real time methods, but they required me to watch. One was an app on my phone that connects to to the inverter and provides a lot of data in real time. The inverter is always monitoring the grid even if it choses not to connect to it. Another was just to watch my municipal meter which displays the voltage as well as other information. I could plug my kill-a-watt into a non-backed up socket as that also shows the voltage at the plug point. So if you notice the battery has gone past 20% and is still discharging then you can have a quick look at the grid voltage. If you only notice after the fact, then it's more difficult. If I wasn't so lazy I'd try to knock up some code on a Raspberry Pi that would poll my inverter every 5 minutes and log the grid voltage. Edited July 9 by Bobster. laziness Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 Apologies for my ignorance but how would i access the BMS setting. Is thus accessible on the inverter? Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted July 9 Share Posted July 9 2 hours ago, CTskollie said: Grid was available yes and was running off from the grid during that period. Would it still deplete the battery with the grid being available below the minimum SOC? When the battery reaches the disconnect level it just disconnects and that why the sudden drop to 0% SOC and bounced back when the BMS reconnect. zivva 1 Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 1 hour ago, Scorp007 said: When the battery reaches the disconnect level it just disconnects and that why the sudden drop to 0% SOC and bounced back when the BMS reconnect. Okay makes sense, I selected grid charge though and then it actually charged it for 45 minutes or so back to 20% so it appears it was actually dead. Reached out to Sunsynk as well and they advised to upgrade my software. Lets hope that helps. Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted July 9 Share Posted July 9 23 minutes ago, CTskollie said: Okay makes sense, I selected grid charge though and then it actually charged it for 45 minutes or so back to 20% so it appears it was actually dead. Reached out to Sunsynk as well and they advised to upgrade my software. Lets hope that helps. If upgrade works this always baffle by 1 brain cell as even the older software should get the info from the BMS and operate correctly. Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 1 minute ago, Scorp007 said: If upgrade works this always baffle by 1 brain cell as even the older software should get the info from the BMS and operate correctly. That is what I was thinking, they offered no advice at all other than to do a system upgrade. Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted July 9 Share Posted July 9 5 minutes ago, CTskollie said: That is what I was thinking, they offered no advice at all other than to do a system upgrade. IT speak. Upgrade must solve all problems? Quote Link to comment Share on other sites More sharing options...
CTskollie Posted July 9 Author Share Posted July 9 2 minutes ago, Scorp007 said: IT speak. Upgrade must solve all problems? Apparently so, might reach out to BSL as well but most likely the challenge is with the inverter. SOH reads 100% on inverter. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.