Thank you for the detailed explanation!

@batpred 

I just came across an article stating that things are moving with plug in panels in the UK! The source is Bloomberg. The link has the english translation of said article.

https://en.protothema.gr/2026/03/26/britain-introduces-plug-in-solar-panels-for-homes-to-tackle-the-energy-crisis-caused-by-the-war-in-iran/

I did some research, but unlike NMC which are special delicate snowflakes, LFPs just don't seem to care about anything except heat (the most important), the usual overcharge/discharge (which the BMS should prevent) and cycling near full charge.

There's this study which says "Cycling near the top of charge (75%–100% SOC) is detrimental to LFP/graphite cells." However, charging the battery instead of using the energy directly is also detrimental to the bottom line because the inverters have 10-15% losses on the roundtrip... So using the energy in real time is both more efficient and saves wear on batteries. In other words, priority to the EV charger and other stuff, battery charging comes last.

There seems to be a linear relationship between total energy cycled and aging, no matter the SOC span of the cycles, except the point mentioned above. So with half-cycles, they will last twice as many cycles... but if I only use half the capacity, then I need to buy 2x as many batteries, so why bother?

They report losing 1% SOH per year which is in line with manufacturer specs. With lots of care and cuddling, the cells will probably last longer than the BMS lol.

Pylontech says do not go below 5% SOC so I set it to 10% to be safe. I will probably add 1-2 more and set it to 30% to have some juice in case of blackout.

I set max SOC to 100% so the BMS can do its balancing. They do age faster at 100% but they don't stay there for long...

I put them in the cellar, the internal sensor reports temperatures around 20°C idle to 30°C at end of charge.

Max charge power is about 10kW so 0.5C, but this only occurs if nothing else wants power. If the car is plugged in, or there are other loads running, home batteries will of course charge slower or just wait for their turn.

Since you seem to quite thoroughly investigate every step you take, how did you choose these levels? I am trying to understand what are the optimal levels to preserve battery health and lifespan.
Sungrow (our battery) documentation suggests a 10%-90% range. We are able to fully charge our 9.6kwh almost every day and now that we have the ASHP, we can also easily drain it on a daily basis. Thank you.

I meant plug-in like just to connect to a socket. 

We do not have Leroy here, but B&Q seems to have tried a similar approach. 

I see that in France, there are plenty of items Leroy sell as DIY.  

Here is an example of local Leroy offerings (in exotic greek...)

A couple of threads highlighting risks and that you may find useful to post on 

Thank you! I did look through them and I got dizzy by the technical level and heated discussion!

Did you consider changing the angle of some of the panels so that no snow can sit on them?

Our PV panels are bolted on the rooftop, they are the first to accumulate snow. What I had in mind is to store the plug and play kit in the garage and only install it in a south facing balcony in case of emergency (having also our house cut off the grid, to be reconnected only after grid restoration would have been completed for grid personnel safety reasons)

Prey what are the SOC% limits you have set for your battery?

12kWp on the roof, 2x Solis S5 6kW hybrids, 20kWh Pylontech

So far pretty good

..

I would be very much interested though to hear and learn from people who have used DIY PV kits as I have not abandoned entirely the idea. And I have extended family who are also interested.

I meant plug-in like just to connect to a socket. 

We do not have Leroy here, but B&Q seems to have tried a similar approach. 

I see that in France, there are plenty of items Leroy sell as DIY.  

A couple of threads highlighting risks and that you may find useful to post on 

• the challenges of the plug-in DIY route these days in the UK
• this one is more about going DIY with classical solar PV

Did you consider changing the angle of some of the panels so that no snow can sit on them?

I wonder if ikea will be selling the balcony diy pv kits there..

I don’t know about IKEA but for sure some DIY chains (like Leroy Merlin) do. A plug and play set of panels that you plug in one socket.

One of the reasons we started the PV+battery journey was staying a week without electricity in 2021 after a heavy snowfall (lots of fallen trees damaged the distribution network).
I’ve been flirting for sometime with the idea of getting as 2nd rudimentary backup such a kit (to be installed on the spot if our rooftop panels are covered with snow, just to power communications) but I was put off by its size…. We ended up with a backup petrol generator that has never been used up to now. 

I would be very much interested though to hear and learn from people who have used DIY PV kits as I have not abandoned entirely the idea. And I have extended family who are also interested.

Those water heating systems do not have the same reliability as PV. With the risk of sounding harsh, are people not replacing those unused systems with Solar PV in Greece yet? 

In fact, the average life span is 20 years and ROI is less than half of that. I dare say nobody replaces solar thermal with PV. The ones who can afford it, add PV panels. Government grants help in household PV adoption, but the installed household base is as of yet an insignificant fraction of the solar thermal one. The fact that in the cities most people live in blocks of flats does not help either. There is however a large installed base of commercial PV parks than contributes significantly to the country's RE consumption.

Thanks, here we have a body MCS that accounts for some significant uplift in PV installation costs. But the connection to the DNO is included when an MCS certificate is produced. I wonder if ikea will be selling the balcony diy pv kits there..

To be honest, I would rather pay €400 to a DNO assuming the rest are standard electricians costs. That seems very good value and your very decent yield must help.