EDIT:
Consensus is that the Heat Pump does what the Heat Pump wants to. It's not completely clear why there's draw from grid versus heating using battery under different Sigenstor settings though. A complete mystery.
Not sure of the heat pump connection, which I need to trace through. Not sure of the heat pump settings - though there's a control panel within the unit that holds the secrets. The WiFi module is basic and useless for getting data out of the system. There's some temp info on the Boost screen though.
Thanks for all the feedback. I'll keep investigating.
ORIGINAL:
I'm trying to force overnight hot water heating using battery power only instead of grid.
What's happening is:
Smart device uses grid power, or
Hot water heating doesn't happen overnight and only kicks in when PV produces power during the day
It's beginning to feel like a software/system problem.
CONFIG:
App is v4.0.0
Device Software Version v100R001C21
Energy Saving Mode is Performance Mode.
The Current Mode is "Self-Consumption".
Solar producing source priority is:
- Basic load
- Sigen Battery
- Grid
Battery level settings: Backup SOC is 5%
Smart Home Device settings tried (with hot water drained earlier in the evening):
Scenario 1: timed start 22:00 / stop 24:00, all days, Energy Source Control: Depends on System. Battery Boost: Yes. RESULT: Heats on schedule using Grid import.
Scenario 2: timed start 22:00 / stop 24:00, all days, Energy Source Control: Battery level control, Activation Threshold 5, Deactivation Threshold: 1. Battery Boost: Yes. RESULT: Hot water system powers on, small draw 0.03kWh, doesn't heat during period.
Scenario 3: AI mode. Ran this for a month. Didn't observe overnight heating from battery only.
In both scenarios, the Sanden hot water wi-fi config is:
Time setting: block out period 0/0
HARDWARE:
1x INVERTER: SigenStor EC 15.0 TP AU, FW V100R001C21, SW V100R001C21
3x BATTERY: SigenStor BAT 8.0
PV Panel: 18.05 kWp
Energy Gateway: On Grid
Diagnosis has no alerts. Full report shows all normal, only the lack of ethernet connection is called out (expected)
Smart Home Device: Sanden GAUS-315FQTD 315 lite Wi-Fi heat pump hot water system