Growatt spf 5000 es discharging batteries every day

Is this normal that my inverter is discharging batteries every day around sunset or sunrise?

The settings 14. Charger source priority:To configure charger source priority: is set to Solar Only (CSO) or Solar Energy or utility (SNU),
but every day I see on the graph discharging like below.

There is not a lot of sun these days in winter Poland hence my set of batteries is hitting 10% even they charged next day and this is causing alarm,
they barely charging each day form solar so I do support them from grid,
however shouldn't be the case in this settings that the batteries are used to feed the home only if settings
1. Output source priority: To configure load power source priority is SOL or SBU?

My settings in 1. is SUB (Battery provides power to the loads only when solar energy is not sufficient and there is no utility.)

Do you experience similar behavior?
My idea was to stay with full batteries and use them to feed home only in UPS mode when there is no grid available.
Please advise

anyone? bump...

Our 3kw Growatt drops to 10% anytime Pv is producing power no matter the battery voltage is.
The way I understand it is that a shunt or battery communication is required for the percentage to read correctly during daylight hours, although I could very well be wrong about that. Hopefully someone will correct this if I am incorrect.

I just click on the "i" icon near the battery symbol to check actual voltage. Not quite correct but it works.

The inverter has idle operating power of 50 - 70 watts and it consumes power from the battery in order to operate and perform its intended function. This is by design. The inverter WILL NOT draws its idle power consumption from utility if battery is connected regardless of SUB selection.

Thanks for answers.
However I did not seen this before that inverter is draining the acu for the whole time with breaks for charging it,
Here comes to me another question why is then not respecting settings 21) Low DC cut-off voltage. or 12) Setting voltage point back to utility source when selecting “SBU priority” or“Solar first” in program 01
and just draining the acu to 39v, for agm is very bad that low voltage,

This wasn't that before for sure, it could be because I installed the the battery balancer ? HA02 HC02 ?

djgrubson said:

Thanks for answers.
However I did not seen this before that inverter is draining the acu for the whole time with breaks for charging it,
Here comes to me another question why is then not respecting settings 21) Low DC cut-off voltage. or 12) Setting voltage point back to utility source when selecting “SBU priority” or“Solar first” in program 01
and just draining the acu to 39v, for agm is very bad that low voltage,

This wasn't that before for sure, it could be because I installed the the battery balancer ? HA02 HC02 ?

Click to expand...

The battery balancer is irrelevant. Can you post all the Growatt settings and your battery model (capacity as well)? I would like to verify something with your settings.

djgrubson said:

Thanks for answers.
However I did not seen this before that inverter is draining the acu for the whole time with breaks for charging it,
Here comes to me another question why is then not respecting settings 21) Low DC cut-off voltage. or 12) Setting voltage point back to utility source when selecting “SBU priority” or“Solar first” in program 01
and just draining the acu to 39v, for agm is very bad that low voltage,

This wasn't that before for sure, it could be because I installed the the battery balancer ? HA02 HC02 ?

Click to expand...

I have the same 2 inverters in parallel, 1 phase. I also had this problem and posted here in another thread: https://diysolarforum.com/threads/growatt-spf-5000-es-strange-charge-behavior.52469/. I did a lot of testing and nothing helped, that is how they work. To solve the problem, I made external 54V power supply.

AshleyL said:

The battery balancer is irrelevant. Can you post all the Growatt settings and your battery model (capacity as well)? I would like to verify something with your settings.

Click to expand...

apologies for late reply I am using 4x 100Ah 12V vrla VOLT batteries, https://voltpolska.pl/index.php?controller=attachment&id_attachment=441

Many of the low cost HF AIO inverter do not have firmware that can tell when inverter idle power overhead exceeds produced PV power. They will continue to run the PV SCC and inverter charging function until the SCC shuts down due to PV voltage collapse.

In order to charge battery, the battery to HV DC converter must be running which consumes most of the inverter idle power. Adding SCC controller overhead of 5 watts or so and you have the approximately 50-70 watts of idle overhead.

Overhead power is taken from battery. When you have enough illumination PV power this net yields PV power excess for charging battery.

In morning and late afternoon when sun illumination is low, the produced PV power may be less then consumed by inverter overhead resulting in some discharge draw from battery. Inverter is not smart enough to figure out the overhead exceeds the PV power delivered and shut down SCC and battery charging.

If you have inverter active to produce AC output the dominate part of the overhead power, the battery to HV DC converter, will always be running. It just changes its mode between reverse charging and forward HV DC creation to power sinewave PWM chopper AC output.