May 17May 17 My Solar Solution:1 x Victron Energy Quattro 48/8000 (Single Phase)1 x Cerbo GX with ESS for Self-Consumption1 x Victron Energy RS450/100 Solar Charge Controller / MPPT1 x 48V Freedom Won 40/32 Lithium-Ion battery1 x Yamaha EF6600 Generator with 2 x 16A Out lets - not in use at the moment.8 x 345W Sunpower CPV Panels, S -25.88, Azimuth: North, Tilt Angle: 30°The ESS Assistant will be removed when I disconnect from the grid. Right now I am running in inverter mode.On Thursday 14/05/2026 06:15, the SOC was 76%. I then created several loads baking some Panini, running a pressure cooker, vacuum cleaner and induction stove. At 14/05/2026 17:48, the SOC was 68%.15/05/2026 06:15 - SOC = 49% MPPT Active for the first time on this day.15/05/2026 17:47 - SOC = 58% MPPT - Off16/05/2026 06:17 which the MPPT State became active, the SOC was 39%.By 12:54, the SOC was 51%. By 13:06, the SOC was 100%.Below is an extract from the logs: 51 - 100% SOC from 12:54 to 13:06.image1174×511 41.3 KBimage1308×702 38.1 KBCan anyone allude to what has happened here?How often will this occur?
May 17May 17 7 hours ago, SRTosen said:Can anyone allude to what has happened here?When did the battery charge to 100% before this?SOC calculations do go out after a few cycles. It could also be that one of the cells require balancing.
May 17May 17 58 minutes ago, SRTosen said:Commissioning was done 01/05/2026 and there have been many 100% SOC's.And deep discharges? (not that 39% SoC is very deep...)Could you also provide your charge and discharge current limits set on your inverter, just to provide the whole picture...I do agree that something does not sound right...
May 18May 18 21 hours ago, SRTosen said:8 x 345W Sunpower CPV Panels, S -25.88, Azimuth: North, Tilt Angle: 30°You will have to upgrade your solar system, you have a 8kw inverter 40kwh battery capacity but you can only have 2760w of solar power available much less during winter. Your maximum yield in winter will be 12kwh if that spit between your loads and charging. So your load demand far outweigh your solar capacity. Edited May 18May 18 by TaliaB
May 18May 18 Author 9 minutes ago, TaliaB said:You will have to upgrade your solar system, you have a 8kw inverter 40kwh battery capacity but you can only have 2760w of solar power available much less during winter. Your maximum yield in winter will be 12kwh if that spit between your loads and charging. So your load demand far outweigh your solar capacity.Yes, I am considering another 3kW of panels but this is not the matter I am raising right now.
May 18May 18 17 minutes ago, SRTosen said:Yes, I am considering another 3kW of panels but this is not the matter I am raising right now.If I may be so bold: You did not actually point out anything specific that you were querying, nor ask a specific question. Most people on this Forum (I assume, based on my own actions...) visit the Forum, open a few interesting looking posts, quickly scans through them, and either leave, or respond to whatever was posted. You unusual SoC jump from 51% SoC to 100% Soc within 12 minutes is hidden within a long, and rather difficult to follow, post. I initially (after scanning your post, asked myself "this looks reasonable, what's this guy complaining about?". Only because I had some time to spare, and was curious because of @frivan post, did I struggle through all your details to find this charging anomaly. I'm sure that @TaliaB would have addressed this, had you actually pointed this out specifically in your post...
May 18May 18 22 hours ago, SRTosen said:My Solar Solution:1 x Victron Energy Quattro 48/8000 (Single Phase)1 x Cerbo GX with ESS for Self-Consumption1 x Victron Energy RS450/100 Solar Charge Controller / MPPT1 x 48V Freedom Won 40/32 Lithium-Ion battery1 x Yamaha EF6600 Generator with 2 x 16A Out lets - not in use at the moment.8 x 345W Sunpower CPV Panels, S -25.88, Azimuth: North, Tilt Angle: 30°The ESS Assistant will be removed when I disconnect from the grid. Right now I am running in inverter mode.On Thursday 14/05/2026 06:15, the SOC was 76%. I then created several loads baking some Panini, running a pressure cooker, vacuum cleaner and induction stove. At 14/05/2026 17:48, the SOC was 68%.15/05/2026 06:15 - SOC = 49% MPPT Active for the first time on this day.15/05/2026 17:47 - SOC = 58% MPPT - Off16/05/2026 06:17 which the MPPT State became active, the SOC was 39%.By 12:54, the SOC was 51%. By 13:06, the SOC was 100%.Below is an extract from the logs: 51 - 100% SOC from 12:54 to 13:06.image1174×511 41.3 KBimage1308×702 38.1 KBCan anyone allude to what has happened here?How often will this occur?As you are indicating something is wrong. Your SOC for a 40kwh battery cannot go from 51 to 100% in 12 min if you only have 2200W from the panels. Are you using comms for charging control as it appears the case with the solar charging current in the table showing volts that were rising. Also the sudden increase to 100% in your graph and no charging while you had enough load connected for the time after 13h06 while the battery did discharge. What does your graph show for 17 May?
May 18May 18 Author 30 minutes ago, HennieL said:If I may be so bold:You did not actually point out anything specific that you were querying, nor ask a specific question. Most people on this Forum (I assume, based on my own actions...) visit the Forum, open a few interesting looking posts, quickly scans through them, and either leave, or respond to whatever was posted. You unusual SoC jump from 51% SoC to 100% Soc within 12 minutes is hidden within a long, and rather difficult to follow, post. I initially (after scanning your post, asked myself "this looks reasonable, what's this guy complaining about?". Only because I had some time to spare, and was curious because of @frivan post, did I struggle through all your details to find this charging anomaly. I'm sure that @TaliaB would have addressed this, had you actually pointed this out specifically in your post...Thank you. Your feedback is noted.
May 18May 18 Author 29 minutes ago, Scorp007 said:As you are indicating something is wrong. Your SOC for a 40kwh battery cannot go from 51 to 100% in 12 min if you only have 2200W from the panels.Are you using comms for charging control as it appears the case with the solar charging current in the table showing volts that were rising.Also the sudden increase to 100% in your graph and no charging while you had enough load connected for the time after 13h06 while the battery did discharge.What does your graph show for 17 May?Thank you for your feedback. I will revert.
May 18May 18 52 minutes ago, SRTosen said:Thank you for your feedback. I will revert.On VRM portal create a Widget to show you battery SOC vs Battery current vs Battery voltage. Also ensure your bms is communicating with the system. Then on VRM check under Battery details for the highest and lowest cell voltage.
May 19May 19 Author On 2026/05/18 at 9:07 AM, HennieL said:If I may be so bold:You did not actually point out anything specific that you were querying, nor ask a specific question. Most people on this Forum (I assume, based on my own actions...) visit the Forum, open a few interesting looking posts, quickly scans through them, and either leave, or respond to whatever was posted. You unusual SoC jump from 51% SoC to 100% Soc within 12 minutes is hidden within a long, and rather difficult to follow, post. I initially (after scanning your post, asked myself "this looks reasonable, what's this guy complaining about?". Only because I had some time to spare, and was curious because of @frivan post, did I struggle through all your details to find this charging anomaly. I'm sure that @TaliaB would have addressed this, had you actually pointed this out specifically in your post...From above:"Can anyone allude to what has happened here?How often will this occur?"
May 19May 19 Author On 2026/05/18 at 9:10 AM, Scorp007 said:As you are indicating something is wrong. Your SOC for a 40kwh battery cannot go from 51 to 100% in 12 min if you only have 2200W from the panels.Are you using comms for charging control as it appears the case with the solar charging current in the table showing volts that were rising.Also the sudden increase to 100% in your graph and no charging while you had enough load connected for the time after 13h06 while the battery did discharge.What does your graph show for 17 May?
May 19May 19 Author Today is not a great solar irriadance day in Pretoria. As at 19/05/2026 14:27, solar total is 2kWh.I will continue to monitor and revert should I see another spike of this nature.Below are some of the key numbers I am tracking.DateMPPT State: ActiveSOC (Active)MPPT State: OffSOC (Off)Yield for the DaY (kWh)Max. Charge Power (W)15/05/202606:1749%17:4958%13.642,42916/05/202606:1739%17:4698%11.832,44617/05/202606:1980%17:3770%9.932,47218/05/202606:2349%17:3663%9.072,427A hearty thank you for all the feedback.
May 19May 19 4 hours ago, SRTosen said:"Can anyone allude to what has happened here?How often will this occur?"I don't wish to get into an argument, but neither of the sentences quoted above points to the presumed anomaly of a sharp rise in SoC within a few minutes - in fact, I am still not sure if the rapid increase of SoC is what you are actually asking about... You will really get proper answers/feedback to your posts if you state clearly what you are inquiring about.
May 19May 19 1 hour ago, SRTosen said:Today is not a great solar irriadance day in Pretoria. As at 19/05/2026 14:27, solar total is 2kWh.I will continue to monitor and revert should I see another spike of this nature.Below are some of the key numbers I am tracking.DateMPPT State: ActiveSOC (Active)MPPT State: OffSOC (Off)Yield for the DaY (kWh)Max. Charge Power (W)15/05/202606:1749%17:4958%13.642,42916/05/202606:1739%17:4698%11.832,44617/05/202606:1980%17:3770%9.932,47218/05/202606:2349%17:3663%9.072,427A hearty thank you for all the feedback.Although at times your system might be playing up the above yields look quite ok for the panels you have. Today is a very bad day in Centurion.
June 2Jun 2 4 hours ago, SRTosen said:Freedom Won has done a Firmware upgrade and I will monitor the behaviour.Trust that will solve the issue.Looking at your log, the big jump was from 51% to 78% in 1 minute. With that size battery that is virtually impossible.I would run that battery down to shut off and then do a full recharge. That should reset the SOC.
June 2Jun 2 1 hour ago, zsde said:Trust that will solve the issue.Looking at your log, the big jump was from 51% to 78% in 1 minute. With that size battery that is virtually impossible.I would run that battery down to shut off and then do a full recharge. That should reset the SOC. This was spot on what I tried to answer in my 1st reply on the question what is going on here. I used the 12min period from 13h00 on 16/05 to go from 51% to 100% for a 40kWh battery from a PV input of around 2200W is impossible. Your 1min period is even more impossible. Seems we were on the same page. We all hope the firmware upgrade will solve the problem in SOC reporting.
June 3Jun 3 Author Battery Firmware was updated from Ver 3.6.3. RC34 to Ver 3.7.2. RC22.The latest profile was also loaded to support the new firmware.
9 hours ago9 hr On 6/3/2026 at 10:29 AM, SRTosen said:Battery Firmware was updated from Ver 3.6.3. RC34 to Ver 3.7.2. RC22.The latest profile was also loaded to support the new firmware.so is it solved ?
8 hours ago8 hr Author 30 minutes ago, esmail-kassir said:so is it solved ?So far yes. I have not seen a spike in the charging from solar since. At the same time, the SOC has not dropped to 51% since the initial event.It subjectively appears that the battery appears to be perfoming better - the yard stick being the SOC when the MPPT switches of and then when it switches the following morning. There are many variables overnight. This also does not exclude lifestyle changes to try and ensure that when the MPPT switches of, the SOC is 100%. I am comfortable with an 80% SOC at about 06:00.Pre‑firmware (01/05/2026 → 01/06/2026, 32 days)Avg SOC at First (morning): 72.8%Avg SOC at Last (evening): 89.0%Post‑firmware (02/06/2026 → 16/06/2026, 15 days)Avg SOC at First (morning): 82.0%Avg SOC at Last (evening): 92.0%Delta (Post − Pre):Morning SOC: +9.2 percentage pointsEvening SOC: +3.0 percentage pointsThe chart below does not contain enough data yet. The blue line is when the MPPT is "Active" and red is Off.
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