Hi all, recently our off-grid system has seemingly stopped charging when it gets to a certain SOC, and only shows minimal solar input (whereas there is actually plenty). If we turn on something with a big load, then the solar input instantly changes to what it should be (see images). It even does the same thing with the generator now too. Originally this happened at around 93%, I spoke to various people, including the local Victron reps who said that it the SOC was just wrong & that I needed to reset it. I didnât think that this was correct, but I did what they said anyway, but now the SOC is just all over the show. It is doing the same thing at 78% now, and running down under 50% overnight!! (Note our usage hasnât changed).
The system is nearly 3 years old & has 3.9kW: 12 x 13V lead acid batteries, 12 panels in 3 series, 5kW victron easysolar with mppt 100/50 smart solar controller.
The local victron people have now stopped returning my calls, so I thought Iâd ask you all. Any ideas??
Hi. You havenât mentioned a specific SOC source, so Iâm assuming itâs coming from the Multiplus. Itâs fairly basic, but essentially it will sync to an SOC value when it reaches the Absorption V set in the Multi. The default I think is 85% SOC and Absorb might be typically 57.6V.
The real issue here may be that your pics all show V under charge down around 52.3V. Thatâs very low, even for a Storage V, let alone Float or Absorb. That you describe your batts as â13Vâ suggests a misunderstanding of how you should be charging what are probably daily cyclers. And that they are still accepting nearly 500W at that low V means that they are nowhere near fully charged. I suspect incorrect charge settings in the mppt.
Hi & thanks so much for the reply! Iâm not sure what the source is, but the Battery monitor and the color control display show the SOC.
The batteries are 12V sorry, so 52V is fully charged from what Iâve been told, as theyâre in 3 series of 4 (4 Ă12V = 48V). If the settings are indeed incorrect, do you know why would this suddenly change after almost 3 years?
With a âbattery monitorâ you have 2 possible SOC sources. Then you need to check in the GX which one is selected. Then understand how to set it up. The manuals are good.
52V may well be typical of your full Pbâs standing for 12 hours with no charge or discharge. But a useless figure if theyâre always in use. The maker should have recommended charge settings, which can be vastly different for standby vs cyclic use. Typically 14.4V (+/- Temp Comp in practice) Absorption for daily cyclers, but Iâd reduce that to say 14.2V because of your parallel strings.
I donât remember ever seeing a complaint of Victron mppts self-changing their settings. No idea there. Have you actually looked? Download VictronConnect from the website.
You may have missed my beginner tag, but I donât understand half of what youâve said sorry. Not sure who the âmakerâ is? You mean the manufacturer of the batteries orâŠ?
Do you mean deep cycle batteries? I googled âdaily cyclerâ but it brought up nothing. I have the victronconnect app, if thatâs what you mean? It only works with bluetooth though & Iâm in bed now. I wouldnât know what is correct anyway?
Im definitely not going to play around with any settings, Iâd want someone who knows what theyâre doing to do it. Trouble is finding one in my country that actually knows these systems is hard. Weâve spent thousands on other issues over the years on so called specialists, only to either find out that they didnât know or that other settings were wrong⊠
Hi @danavancampen
Post a screenshot of the mppt settings so we can tell you if itâs âokâ or which parameter to change
Where do i find these please? Iâve had a look via the remote console but couldnât see any settings for the MPPTâŠ?
not in VRM; use the âvictron connectâ application and put yourself next to the solar charger then connect to the MPPT then go to the settings (top right)
Oh right, thanks! Will do it tomorrow as itâs 1030pm here & the system is outside 
Those settings are ok. But donât match the Battery V reported in your first pics which show Float status. And you can tell by the higher PV Voltage that output W is being limited. The only real way this can happen is that the BMV Voltage sensor is attached to the battery and showing a low V, but the mppts see a higher V. So there might be a partial disconnect in the battery supply wires. Not unusual for Pbs with terminal corrosion or something like that.
Not sure how you found production figures with Connect at 10:30 pm, but if you look at those figures when back in this condition, the Vâs there should all match, and match with VRM Dashboard. If not, look for a wiring fault.
Edited⊠Ah ok @youn, I mixed up the posters, my bad. Iâll leave it up though, might still be relevant if the OPâs settings are similar.
Hi @JohnC
It is normal that these parameters are ok ; these are mine, my installation works; I put these screenshots so that @danavancampen has a reference to know where to find the settings. 
Try the UPDATE or Battery>
You have to start with the updates and the parameters are in the battery menu.
Another point that worries me is the difference in voltage between the BMV and the MPPT, 3V difference could mean a problem with the connections.
If you have a multimeter measure between the voltage between the two ends of the cable the voltage drop should be less than 0.3V.
Another detail send me a screenshot of the âVE.Smart networkingâ menu (unless the DVCC is active in the GX).
Sorry for late reply! Iâm sick with bronchitis at the moment. Hereâs the settings on our battery page in the Victron connect app. Do these help?
I was also concerned about the difference in voltage between the BMV and the MPPT! I will ask my sparkie about that
The settings are ok ; So check your wiring, it must be faulty somewhere; to find the faulty point(s) check if there is no hot point because 2.57V loss at 8.66A means 22.2W loss in line it is quite high for this power (3.5%)
Hi youen, can you please explain which cable to measure the V drop? Between the batteries and the shunt or�
@danavancampen
Just use a multimeter as a voltmeter and measure as follows:
system in charge, you measure on the same cable but at the 2 ends.
example we want to measure the voltage drop on the cable between the inverter and the shunt: you put a measuring tip on the cable on the inverter side and the other on the cable on the shunt side and you read the value.