Great. They can also use tools to check the battery logs, make sure it’s happy and there isn’t a bad cell.
I know Pylon have updated some of their firmware as well. So if everything checks out then getting up to date will also help.
They should be able to check all the VRM charts/data (presuming it is calling home) and see if there is anything obvious in the data.
If the battery is getting to it’s 52.4V and cell differences are ok, then you won’t be breaking anything short term.
IMO PylonTech batteries are good but I don’t like them being 48V nominal batteries when nearly everyone else doing a 48V system is using 16S (51.2V) rather than 15S (48V). This means you can’t mix and match them with other brands or even some of their own batteries which are 51.2V.
Your problem is most likely as Nick said, a cell imbalance. Remember at 52.4V your cells are actually at an average of 3.493V per cell - that is likely more than 95% - probably over 98%. SOC at the upper end of the LiFe charging cycle is a bit of a guessing game because it depends on a bunch of variables, charge rate, temperature, etc. As soon as you take them off charge they’re going to rest at 3.4V per cell anyway. On the BMS I use I can tell it to consider 3.5V 100% SOC - I’m not sure if you can do that on the PylonTech - it’s probably locked down.
Thanks John.
I’d be perfectly happy to consider 95% as 100% SOC if Pylontech allowed that but don’t think I can do it.
As to cell balance, this is what I see:
I know next to nothing about the internals of Pylontech nor about LiFePo4 SOC estimation method but I would have guessed that it integrates the current going in and out and that any errors in there will accumulate unless the integration is reset when the battery is full. But this is just guess work.
WhenI get to the cottage I will first update the firmwares and then I think I will disable my boiler kicking in at 98% SOC which happens around 20:00 everyday when there is no more enough solar power to feed the boiler AND charge to 100% SOC.
I hope I can then reach 100% SOC in the evening.
I will then modify the boiler to start at 90% SOC which should happen before noon and hopefully there will be enough solar power to both charge and heat water and water heating will be done before the sun goes too low on the sky and then the remaining power will bring the SOC up to 100% everyday.
That seems a perfectly balanced group at 100% SOC… 
Thanks Alex. That was my un-educated feeling too. So to me it looks something like I speculated that the Pylontech SOC algorithm is out of whack (or there is a systematic measurement error that accumulates) just a bit but enough to delay the 100% SOC detection to an unfortunate time of day (ie evening).
Also, if the above figures are for a below 100% SOC, then which are the followings, in the exact same moments:
Both found on Pylontech menu, first on the first line of that menu, together with voltage and power, the second on the Parameters submenu.
If the CCL is different than 0 then one or both of the batteries are still charging/balancing.
Also, I’ve seen cases when CCL is 0 and the battery is still balancing and in that case the battery’s current to be something like 0.1A or a little bigger.
I will check the values this evening when the situations repeats.
Here is sample of the values I see. The charge/discharge current fluctuates between charging, not charging, discharging at some 10-15 second interval with no apparent pattern.
From the first (over vied picture) you can see the two consumption spikes (AC Loads) last night when SOC was 98% (or over) twice and from the PV Charger plot you see how the over night consumption was quickly replenished some hours ago and now the SOC has been stuck at 92% for some time.
FYI
Yesterday finally the stars were aligned and the system reached SOC 100% and the water boiler also reached turn off temperature. I am not sure if these are related cause the water heating started at SOC 98% (around noon) and continued well beyond the time SOC 100% was reached.
A particularly sunny day might explain this but Yesterday we had rain and cloud with some sunshine.
Also today SOC 100% was reached around noon.
