Growatt SPH3000 Stops discharging from 21:00 to 21:20.

[Halude]

Hi All,

I wonder if you can help me please, i have had a SPH3000 Growatt inverter installed with batteries,

So far every day we are seeing the following

1. inverter stops discharging the batteries and pulls from the grid for around 20 or so minutes around 9pm each night.
2. early in the morning when boiling the kettle getting random spikes pulling the energy from the grid when the battery has excess charge

Below is a graph from today with the corrisponding battery level.

If anyone is able to guide me in what would be causing this and how to resolve would be greatly appecaited.

 

[binky]

Spikes will be due to battery algorithms and how they respond to a heavy load like a kettle. Your other issue sounds like a maintenance thing, ie the battery is checking itself, balancing out the cells, or something like that.

 

[johnb2713]

Do you have solar PV as well? (the graph suggests you do).

My Growatt SPH inverter does exactly the same at effectively sunrise and sunset, according to tech it's the inverter running a self diagnostic mode which I dont believe, but the timing tie with panels starting output and shutting down.

 

[binky]

Do you have solar PV as well? (the graph suggests you do).

My Growatt SPH inverter does exactly the same at effectively sunrise and sunset, according to tech it's the inverter running a self diagnostic mode which I dont believe, but the timing tie with panels starting output and shutting down.View attachment 13880

Inverters do go through a self check at starting up in the morning, not sure if hybrids do this as well.

 

[johnb2713]

Inverters do go through a self check at starting up in the morning, not sure if hybrids do this as well.

Whats to self check and why does it take so long?

In my installation the inverter never stops due to solar PV and battery.

 

[Halude]

Thanks All,

Thanks for your responses and is similar to my other google searches, I do have Solar PV but will keep monitoring my usage.

I wam having a call with the installation person tomorrow and will bring this up with them and bring up why i am discharging to the grid from my battery

 

[binky]

Whats to self check and why does it take so long?

In my installation the inverter never stops due to solar PV and battery.

PV inverters always check the DC insulation and the AC supply before starting up in the morning. You wouldn't notice this as it occurs when there's sufficient voltage from the panels to activate the inverter from overnight stand by mode, but not necessarily enough to actually get going. It's quite normal to hear various relays clicking in the morning as it trys to start work for the day - something else RCDs can object to. I've not lived with a hybrid, so don't know what they do. I suspect that if the battery is discharged, start up from PV in the morning would be the same. If there's still charge in the battery, then I don't know what happens, but I would guess a self check occurs at some point when the PV isn't supplying power. The self check is an important safety aspect of PV systems, all inverters do this, so I'm guessing it's in a standard for inverters somewhere like G99. It usually takes less than a minute, so a half-hour shutdown doesn't seem right to me as per the op.

 

[binky]

Thanks All,

Thanks for your responses and is similar to my other google searches, I do have Solar PV but will keep monitoring my usage.

I wam having a call with the installation person tomorrow and will bring this up with them and bring up why i am discharging to the grid from my battery

View attachment 13886

Interesting, I can understand the energy spikes with the kettle on, but leaking a bit to the grid doesn't make sense unless the algorithms are a little poor. I have to say I've never liked Growatt, I'm beginning to think my bias is justified

 

[johnb2713]

PV inverters always check the DC insulation and the AC supply before starting up in the morning. You wouldn't notice this as it occurs when there's sufficient voltage from the panels to activate the inverter from overnight stand by mode, but not necessarily enough to actually get going. It's quite normal to hear various relays clicking in the morning as it trys to start work for the day - something else RCDs can object to. I've not lived with a hybrid, so don't know what they do. I suspect that if the battery is discharged, start up from PV in the morning would be the same. If there's still charge in the battery, then I don't know what happens, but I would guess a self check occurs at some point when the PV isn't supplying power. The self check is an important safety aspect of PV systems, all inverters do this, so I'm guessing it's in a standard for inverters somewhere like G99. It usually takes less than a minute, so a half-hour shutdown doesn't seem right to me as per the op.

Mine still does this still having plenty of charge in the battery, why would it take 10 minutes to check insulation?

 

[johnb2713]

Interesting, I can understand the energy spikes with the kettle on, but leaking a bit to the grid doesn't make sense unless the algorithms are a little poor. I have to say I've never liked Growatt, I'm beginning to think my bias is justified

Mine seems to keep testing the grid and kind of checking the voltage. It seems to reduce it's voltage until it takes a bit of import 10w or so and then increase the volatge so it its exporting slightly. The cycle repeats, it doesnt add up to qa lot of power, typically 1 kWh per day or thereabouts

 

[binky]

Mine still does this still having plenty of charge in the battery, why would it take 10 minutes to check insulation?

No idea, that has to be a function of the programming.

 

[binky]

Mine seems to keep testing the grid and kind of checking the voltage. It seems to reduce it's voltage until it takes a bit of import 10w or so and then increase the volatge so it its exporting slightly. The cycle repeats, it doesnt add up to qa lot of power, typically 1 kWh per day or thereabouts

Grid voltage is constantly monitored, it has to be to keep output voltage a couple of volts above the grid. Losing a kw seems a lot, but I think we need to look at the bigger picture of how much energy you get to use/ keep yourself.

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