Hello !
Dear friends, it is about two months now since I have installed a small grid assisted solar setup for personal use. My current setup is: 12x Longi 535W bi facial panels, 2x Growatt SPF 5000ES inverters working in parallel, 2x Dyness battery packs with total of 9.6kWh capacity and 1x WiFi communication dongle. Since the beginning I've noticed very erratic behavior when there is no sufficient or no sun power. My current "back to AC" setting (12) is at 25% battery, "back to battery"(13) is at 30% and the ''low DC cut off'' (21) is at 20%. After reaching 25% battery capacity, both of the inverters are indicating that they are in AC bypass mode but the battery slowly( in about 2-3 hrs) continues to discharge to 20% ( even being all the time in AC bypass mode) and than the ghost has two scenarios: 1. Grid AC charge the battery to 30%; 2. the battery continues to discharge to 0% and the whole system shuts down or grid AC is starting to charge the battery from 0% to whatever percentage the ghost choose (this morning stopped at 54%).
So I am tying to figure out why after reaching 25% there is still battery "leakage" and is this battery or inverter problem, or the communication between them is somehow not OK ? If I have to be honest the fact that sometimes the battery continues to discharge to 0% is bothering me the most.
What have I tried so far:
1. Tried both CAN and RS485 communication with the battery with according jumper setup on the front panel of the master battery (no error 20).
2. Switching places of the inverters (master-slave).
3. Tried the original Dyness (straight) communication cable (works in RS485 mode with protocol 01 in menu 36 and also this cable works in CAN mode with protocol 51 in menu 36) and also made my own cable (1 and 2 pins on inverter and 1 and 3 pins on battery working only in CAN mode with protocol 51 in menu 36).
4. Switching places of the batteries (master-slave).
5. Disconnecting ground from the battery and then from the inverters (just trying).
6. Reset the inverters with 305 code before changing any major setting.
7. Saying many bad words.
Other settings: 01- SBU; 02- 50A; 03-UPS; 04-DIS; 05-Li; 12-25%; 13-30%; 14-OSO; 18-ON; 21-20%; 23-PAL; Firmware: 067 01 1.04, 068 01 1.04
I will be really grateful if someone have an idea what might be the problem and how to solve this puzzle !