Consultation for photovoltaic system

I can’t say for sure because I haven’t had the new system for a full year yet; I only had the first full month in the current combination in May.

Have you been able to figure out how the charging algorithm works?

For maximum lifespan, Li-ion batteries are supposed to be kept at about half charge (as opposed to lead batteries, which should be kept as full as possible).

That is, how does the charging continue depending on the time of day when the battery is half full (about 3.8V/cell)? Or what does the charging control do if the battery has been fully charged for several days and no consumer wants power? Does it then discharge itself to 50%? It could, for example, charge so that starting at about 18:00 it charges further/higher if 100% was not reached the previous night and the battery was quite drained in the morning. If there was still enough remaining capacity before sunrise, it could stop charging at 50% around noon.

In other words: Can the charging curve be selected between maximum battery lifespan and maximum power availability? Or does it learn to optimize itself?

i.e. how does the charging continue depending on the time of day when the battery is half full (approx. 3.8V/cell)?
Or what does the charge controller do when the battery has been fully charged for several days and no consumer wants power? Does it then discharge itself down to 50%?

This is possible with a smart home control system that knows a forecast of the expected consumption and, if necessary, has a vacation mode. The interfaces are available. Not in my case, as I do not have a smart home. On the other hand, I have never had a full charge state lasting for several days.

It could, for example, charge further/higher from around 6:00 PM if 100% was not reached the previous night and the battery was quite low in the morning.

For that, the coupling to weather forecasts exists — not yet integrated in my model, but will come with an update within the next ? years.

If, on the other hand, there was still enough residual capacity before sunrise, it could stop charging at 50% by noon.

This programming would then be useful if you know that you will not need the charging capacity. In combination with the smart home control, this is possible (see above).

Can you select the charge curve between max battery lifetime and max power availability?

Yes. I have a 10-year full warranty without limitation of charge cycles and do not charge gently with a maximum C-rate of 1.

Or does it learn to optimize itself?

Not yet.

Also clever is the possible prioritization without a smart home, for example for power to heat in the hot water storage, charging station for the e-car...

I find the combination of a battery system and spot price tariff in winter exciting. But it is not yet available in my device either, although it can basically be delivered later as an over-the-air update.

What exactly makes your system premium then? I have a regular SMA system and there is a checkbox "forecast-based charging," I click that, set a threshold from which it applies (e.g., always charge the battery up to 20% and then switch to forecast-based), and it runs considering the weather forecast as well as the load profile. Costs nothing (not even time) and requires no smart home connection (which I don't have either). I could also use different tariffs, temperature increase for heating/hot water, etc., but that's too fiddly for me and effectively brings almost nothing (for me). I don't know the battery charging curve and I'm not interested either - I assume LG Chem and SMA can handle that without my input :)

What exactly is premium about your system then?

Only the price... Nah, I don’t want to do any product advertising here. I also know the device professionally very well, as the manufacturer is a client. Happy to share more via private message.
With SMA, you didn’t buy a cheap product either. There are good reasons for that.

I find forecast-based charging sensible when weather and consumption forecasts are combined. Since my storage tank won’t remain full for days even in midsummer (unlike this year), the weather forecast was not yet a deal breaker for me.

Pretty demanding. But okay: The rule of thumb is €1000 per installed kWp as well as installed kWh storage. Currently, due to material shortages, about 10-20% more expensive. There's no suitable storage, because it’s nonsense. Installation is included. Everything else depends on your house, so you’d best discuss that with the solar installer. Maintenance, given your low roof pitch, would possibly be cleaning every few years.

What I’m getting at is that “it’s currently not worth it for saving money” is being presented. As long as savings only occur earliest in 10…15 years (theoretically), it’s never really worth it. By then, repairs/failures will occur on one or another component. That’s just the way it is. It already annoys me with the now 12-year-old electric blinds. (No mechanical defect). First failure after 9 years. So far, 3 replaced and another one is already looming. As long as it’s not profitable in 3-5 years, the “PV stuff” will never really pay off—except for the seller, of course. And I say this as an electronics technician. ;)

...As long as savings are made at the earliest in 10…15 years (theoretically), it will never be worth it in life.

that is due to politics: instead of solving problems politically-strategically "at the top," they are passed down "below." With monetary control mechanisms, you can allow yourself any nonsense as long as there is enough pekunia in the account. Those "down there" without a relevant account are then supposed to restrict themselves sensibly.

Restrictive control mechanisms are then politically not enforceable, see above, because of the outcry of "paternalism"

As long as the survival of the climate does not pay off, nothing will come of it.

A pity really, otherwise this world could be quite nice. If only the Ahr and its sisters would not flood.