Some thoughts regarding batteries and ME3000SP inverter integration:
- 50ah pylontec 2.4kw US2000 plus (original) - If I understand correctly ME3000SP inverter support it out of the box
- 66AH 3kw Tesla battery - may be SimpBMS. It can read data from original TESLA BMS and then translate data to the inverter, but not sure whether ME3000SP is supported.
- for other batteries without any BMS - REC SI BMS, It can work with up to 16S battery configuration and supports various type inverters. But I don't have personal experience with that system.