I want to build an offgrid system that mainly will be used during the summer.
Briefly outlined:
Energy generation, storage:
- Phoenix Combi 12V / 1600W (we already have)
- 4x PV panel 300W
- MPPT 250/100
- Car battery 12V 45Ah
Consumers:
- Waterpump 1 phase 800W - 230V, 1h/d during summer
- Intrusion detection (SMS module ca 5W, 24h/7d)
The system will be placed in a gardenshed.
The following questions come to mind:
- On a sunny day, will the power flow directly from the MPPT to the inverter?
- Plans to a future upgrade to a 48V system. I made calculations for the battery pack and the result was a 4x 12V-110Ah Gel battery combination. This was based on the rule which limits the maximum charge and discharge currents in regards to their expected lifetime. For this 48V system i need 3 battery balancers, which have their costs. My friend google found the Pylontech or Liontron LiFePo rack system. These systems have an integrated BMS. Can I use the Multiplus II GX or EasySolar II GX for the communication with the BMS of the rack battery? Or do I need an seperate GX device. And what power consumption is to be expected from this GX device.
- Do I need in regard with the future, buy the MPPT with ve.can functionality for communication with battery rack?
- Shouldn't Victron upgrade their MPPT's to higher voltages? I understand that more PV-panels on a string is a better choice. 250V seams limited to me for future design, if compared to AC-grid inverters.