Weird voltages PV

[handyandypt]

Hi.
I am a total solar virgin with Easun hybrid inv. 5k single, 100Ah Lifepo battery and 3 x 460W Amerisolar mono perc 144 and 1 x 450W DSK mono 144)
Setting are:-
(01) - SBU
(02) - 30amp
(11) - 30amp
(12) - 48v
(13) - 51v less utility usage
(26) - 52.8v Bulk
(27) - 52.5v Float
(28) - 51v
(29) - 44v Low Voltage Threshhold
Things are ticking along with only the kettle, first thing in the morning, causing the system revert to mains.
I had previously checked PV voltage before going live and the voltage was a stable 180v midday.
If I check the voltage in service the voltage fluctuates between 220v and 0v but the controller seems to be working OK.
Is this normal or have I got a controller problem?
Cheers

 

[RCinFLA]

Your charger voltages are set way too low. With bulk of 52.8v, that is only 3.30v per cell which is close to 50% state of charge assuming cells are balanced. At this level there will be no balancing and cells will degrade in balance over several months.

For 16S LFP you need Bulk to 56.0 to 56.8v, float to 54.4 to 54.6v.

Bulk is required, at least periodically, to allow BMS some time to balance cells.

How are your panels connected and placed in relative orientation?

Single 100 AH battery is not going to give you much run time. Don't forget about idle current draw on inverter, likely 1.3-1.8 amps from battery.

 

[chrisski]

If I check the voltage in service the voltage fluctuates between 220v and 0v but the controller seems to be working OK.
Is this normal or have I got a controller problem?

The only time I get 0 volts is when the sun is at night. Even on a cloudy day, there’s enough voltage to charge a battery. If the batteries are charged, the voltage reads pretty close to VOC, but delivers 0 amps.

If I had 0 volts in the day with my Victron SCC there would be a problem. In my case with a portable setup, voltage was 0 from things like, a connector got kicked out, a pin was recessed inside a connector, or a set screw in a combiner box had backed out.

 

[handyandypt]

Hi Guys,
Thanks for feedback. I'll adjust voltages but these settings are culled from a variety of forums - all experts!
When I say the PV voltages vary it's between a few seconds with the variation between 220 and 0 and back to 220 - not right.
The 4 panels are in series. 48v x 4. 10 amps.
P.S. I have ordered another 100 AH battery

 

[handyandypt]

OK. Much water under the bridge. The main confusion is that there can be 14, 15 or 16 cells per battery. The popular Pylontech are 15 cells but the 100Ah units I have been buying are all 16 cells so the voltage settings are different. I am using Solar Assistant which gives me total control and monitoring with graphs to determine best grid in/out points.
At the moment I have switch-to-grid voltage of 46v, back-to-battery voltage of 53v and battery charge of 56.8v which seems optimum to this setup.
Different batteries seem to have a different range of voltages, so the solar assistant is the ideal tool to fine tune your system.