Electrical/Solar help needed

Initially, I decided to buy a factory-made 16 kWh battery pack and sell my existing one, but I was told that they could be combined into a single system. Since I could only sell my old battery for a very low price—even though it contains high-quality CATL cells—I decided to connect the two battery packs, which have different capacities and different BMS units, via an electrical busbar.

The original Victron busbar is very expensive, so I decided to build one myself.

In addition, I constructed a sturdy, insulated platform using 15 cm of polystyrene foam, and provided space heating via a film-type heater with a thermostat, as well as an electric convector heater, also equipped with a thermostat.

Once the battery arrived, I connected everything into a single system.

Затем необходимо было запустить всю систему вместе, я зарядил оба аккумулятора, сделал чтобы показатели на клеммах были одинаковые показатели, сделал предзаряд конденсаторов лампочкой и запустил 2 аккумулятора

It was a bit scary, but everything worked out; the system is up and running. I also added a 12V battery and set up backup lighting.

I have an inexpensive inverter with limited functionality. I replaced the stock Wi-Fi logger with a custom one based on an ESP32. We have a preferential (lower) electricity rate at night, and—provided there are no blackouts—I can make efficient use of the system thanks to my 21 kWh battery bank and this smart logger. The custom logger allows for integration with Home Assistant and also enables the control of Tasmota-based devices.