Matthias M.
The battery makes a very solid and high-quality impression, and the German operating instructions are also really first-class and logically structured.
It would of course be better if a 200A BMS were installed so that an inverter with 2000 watt output power could be operated without any problems.
I also find the screws supplied with the connection terminals to be too short to connect two cable lugs one above the other.
It would be better to have 3 terminals next to each other per battery pole in order to avoid double occupancy.
It's also a shame that this type of battery with a metal housing is only available as a 12-volt or 48-volt system.
A 24-volt system in the same design would complement the series perfectly and would have been my favorite.
I personally find a series connection of two 12 volt batteries disadvantageous because the voltages of the individual batteries can then drift apart over time and one battery is already full while the other is not yet fully charged and the BMS prevents the weaker battery from being charged further .
Same when discharging.
There is a risk that, over time, one battery will be almost completely discharged before the BMS switches off in the event of undervoltage, while the other battery still has sufficient voltage available.
That's why I decided to connect two of these 12.8 volt batteries in parallel to always ensure the same voltage in both batteries.
The photo of my system is even older, from January of this year.
My system is currently being converted, with two Powerqueen batteries connected in parallel and two inverters to power my household.
When the system is finished, I would be happy to send more pictures...