Kia ora all from New Zealand!
My system has evolved over the last 3 years or so and works well except for a few niggles, supplying the house and also often able to AC charge an EV or two. We are
- EasySolar-II GX 48/5000/70-50 MPPT 250/100, no grid input and only AC Out 1 is currently in use
- 12x Trina Honey panels (each 320 Wp, Voc 40.3 V, Isc 10.2 A) wired as 3s4p oriented 45 degrees elevation, ~15 degrees East
- 8x 12v AGM (each 200 Ah at C10=20 A) wired as 4s2p, I treat them as having half that capacity in practice.
- BMV-700 monitoring the AGM batteries, VE.Direct to the GX device
- SMA SunnyBoy 3000 MPPT plus grid tied inverter, connected to the EasySolar’s AC Out 1. Uses the EasySolar’s Multiplus ESS wizard to choke back the SunnyBoy’s AC output by increasing the AC clock frequency when the batteries are full.
- 12x 390 W solar panels, each Voc 48.5 V and Isc 10.5 A, wired 12 in series. The SunnyBoy is fine with <700 Vdc from the panels, but limited to 15 A so the 12s1p is necessary. These panels are elevated 45 degrees and oriented 30 degrees West so they optimally gather afternoon sun.
- 2x 48 V, 100 Ah LiFePO4 batteries (unbranded but perhaps BSLbatt) each with a BMS, coupled together by RS485 as well as DC, and communicating with the EasySolar GX device over CANbus. These batteries are now the primary source and sink of DC current, but they are in parallel with the AGM batteries.
How we assembled this arrangement is a long story but apart from occasional glitches it works.