I have 5k Deye inverter and lithium Deye battery. The system is connected to grid and there are no inverter consumers as well as no PV connection. Under such simple conditions, stats tell "total consumption power" is 41W and "battery power 79w" (battery SOC percentage slowly drops from 100 up to the point allowed by TOU threshold setting). I'm very much surprised where does 79w come from - there are no consumers and grid is up and running. I was expecting battery to not discharge at all when grid is on - what am I doing wrong?

52 minutes ago, Amf said:

I have 5k Deye inverter and lithium Deye battery. The system is connected to grid and there are no inverter consumers as well as no PV connection. Under such simple conditions, stats tell "total consumption power" is 41W and "battery power 79w" (battery SOC percentage slowly drops from 100 up to the point allowed by TOU threshold setting). I'm very much surprised where does 79w come from - there are no consumers and grid is up and running. I was expecting battery to not discharge at all when grid is on - what am I doing wrong?

From your description, nothing sounds wrong, this is just how it works.

The inverter itself has a self-consumption to power its own inverter electronics, screen, fans, wi-fi, communications to the BMS, etc.

If you are enabling the TOU function, you are essentially activating/controlling the use of the battery. The system is doing exactly what you're telling it to do, which is to run down the battery instead of the grid.

If you don't want to use the battery, then either disable the TOU function, or keep the percentage at 100%, or limit the battery Power to 0 Watts on the TOU screen.

I did not consider option to set power to 0, I'll give it a test, thanks. I wonder what it will do if power is set to 0 Watts and grid is suddenly gone. Still it is counter intuitive to me - why would anybody want to use battery when grid is available and voltage within functional range.

15 minutes ago, Amf said:

why would anybody want to use battery when grid is available and voltage within functional range.

If they have solar panels, then they definitely want to drain the battery before using the grid, but in your situation it is best to prioritize the grid.

1 hour ago, Amf said:

I did not consider option to set power to 0, I'll give it a test, thanks. I wonder what it will do if power is set to 0 Watts and grid is suddenly gone. Still it is counter intuitive to me - why would anybody want to use battery when grid is available and voltage within functional range.

When the grid is gone, the time of use function settings will be disabled, and the inverter will simply switch over to the battery.

There could be financial reasons why someone chooses to run from battery instead of grid. Like I'm doing it to avoid peak-time Eskom/utility rates.

Had a chance to do some testing, and I have to say results are weird

Conditions:

1. TOU is checked

2. Grid Charge and Gen are checked next to time interval in question, with Power 0 and Batt 85%

3. When grid disconnected battery SOC was 100%

 

Outcome:

Smart Load was feeding small appliance (fan, consumes 8W per spec, Deye tells 16 something) for some time (hours) and then switched off. Honestly I'd be expecting Smart Load to be off asap in my condition (no PV), so I was surprised it was on for so long, but also was surprised it disconnected for no apparent reason (battery did not reach 85% SOC by far)

"If you don't want to use the battery, then either disable the TOU function, or keep the percentage at 100%, or limit the battery Power to 0 Watts on the TOU screen."

Referring to the above suggestion.

I'm have some difficulties with the Pylontech battery (only one).

The battery (Pylontech US2000C) starts discharging when there is no more solar power available. So far, it begins discharging anytime from 19:00 until the panels can start charging the battery again. It discharges down to about 80% plus throughout the night, even if there is no solar power during the day.

The battery is connected to a Deye SUN-5KSG01LP1-EU.
Battery serial number: H230220C30290075

The Deye setup is as follows:

    Load first
    Gen charge and Gen signal: Off
    Lithium mode: 0
    TUO: Disabled

The battery is charged by the solar panels and only functions when there is no AC power or during load shedding.

Any advise.

Thanks in advance.

1 hour ago, jjvvuuren said:

I'm have some difficulties with the Pylontech battery (only one).

No problem with the battery, your inverter will and must use power from the battery to power internal load etc - normal behavior if you use solar & battery as a ups.

Edited February 13, 20251 yr by Demo
Spelling

I do understand if there is no grid AC available it must use the solar and battery, however it drains the battery when there is AC available.

My other concern is the amount it uses is 20% plus.

Or my inverter settings are incorrect.

3 hours ago, jjvvuuren said:

I do understand if there is no grid AC available it must use the solar and battery, however it drains the battery when there is AC available.

My other concern is the amount it uses is 20% plus.

Or my inverter settings are incorrect.

I would depend what your setting is under the timer section and if you have the use grid ticked. 

My 5kW has a 50-60W drain from the battery when I have AC not connected. This is shown under the load value on the RHS at the bottom. This value is the self power when all loads are switched off. 

12 hours ago, jjvvuuren said:

My other concern is the amount it uses is 20% plus.

Over what period of time? 20% of a 2kWh battery is 400Wh. If that's over an hour then thar seems on the high side, if it's over a day then it's low. 

10 hours ago, Scorp007 said:

I would depend what your setting is under the timer section and if you have the use grid ticked. 

My 5kW has a 50-60W drain from the battery when I have AC not connected. This is shown under the load value on the RHS at the bottom. This value is the self power when all loads are switched off. 

Thanks. I can understand if there is no AC but in this case there is AC available.

1 hour ago, Bobster. said:

Over what period of time? 20% of a 2kWh battery is 400Wh. If that's over an hour then thar seems on the high side, if it's over a day then it's low. 

It starts to drain the battery just after 19:00 when there is no solar power left and starts loading the battery the next day when there is sufficient solar power.   I'm adding my current settings. Any advise will be great, thanks.

I don't have any experience with that inverter, so I can't advise on settings.

But the inverter needs power to keep running, and it must get that from somewhere. So let's say there's an 11 hour period between 19:00 and useful PV being available. 20% of the battery, as we said, is 400Wh, so over 11 hours that is a 30 to 40W draw. That's not a lot to keep an inverter running, but almost certainly that is what is happening.

Most hybrid inverters, in their default mode, will try to service the load, including self load, from PV first, then battery, then grid if available. After all, most people buy them to reduce draw from the grid.  But that can be overcome with settings.

@Bobster. Thanks for the info.

My experience is limited on both ends.

The battery capacity is rather limited.

I was hoping to be able to set the battery usage to the minimum and have it almost fully charged in case of power outage or load shedding.

Any suggestions?

1 hour ago, jjvvuuren said:

Any suggestions?

Unfortunately not. I have no experience with that particular inverter. But what you're describing is not a Deye thing, it's a hybrid inverter thing. They are electrical devices, and they have to get power from somewhere.

Get a manual. They'll be available for download somewhere.

Edited February 14, 20251 yr by Bobster.

@Bobster. Thanks for the reply.

@jjvvuuren

Set Zero-export Power = 100.

Save and check how it works now.

@Youda Thanks will test.

6 hours ago, jjvvuuren said:

It starts to drain the battery just after 19:00 when there is no solar power left and starts loading the battery the next day when there is sufficient solar power.   I'm adding my current settings. Any advise will be great, thanks.

Untick time of use in the second pic 

 

And Untick activate battery in the 6th pic. That's only when battery is dead. 

 

Try that 

@abd7 Thanks, will test.

10 hours ago, jjvvuuren said:

It starts to drain the battery just after 19:00 when there is no solar power left and starts loading the battery the next day when there is sufficient solar power.   I'm adding my current settings. Any advise will be great, thanks.

 

Here you have selected the battery to remain at 100% all the time but you did not tick any grid use to keep it at 100%.

Put a tick mark at GRID CHARGE. I will also reduce the 100% to 95%.

On the next slide you did indicate every day. These 2 pages gives permission to charge from the grid.

If I have it wrong can our thousands of users please jump in to help.

By using only a 25Ah battery and some load you can expect to use nearly 80% of the battery in the period with no PV thus you HAVE to tick using grid charge to keep the inverter on. Info on slide 6.

Edited February 14, 20251 yr by Scorp007

To keep the battery fully charged all the time you can just untick "time of use". 

If you wish to drain to specific SoC % at various times in the day then tick it, and set according to your requirements. 

20 hours ago, Youda said:

@jjvvuuren

Set Zero-export Power = 100.

Save and check how it works now.

I have set Zero-export Power to 100. This morning battery was drained down to 75%

9 hours ago, abd7 said:

To keep the battery fully charged all the time you can just untick "time of use". 

If you wish to drain to specific SoC % at various times in the day then tick it, and set according to your requirements. 

I unticked the  TOU but the battery was still drained.