Battery discharging to grid

[JohnW]

I finally got my first battery fitted last week and on Thursday it charged to 86%. However, as the sun set, the battery started periodically exporting to the grid. It This was not continuous, it discharged for a few seconds then we'd import a bit before switching back to exporting again. This continued until the battery reached 20% then stopped.
Is this normal behaviour, as it seemed quite alarming to see my stored electricity disappearing?

I have a Solis hybrid inverter and Pylontech US5000 battery.

Any suggestions gratefully received.






Many thanks

[Joeboy]

I finally got my first battery fitted last week and on Thursday it charged to 86%. However, as the sun set, the battery started periodically exporting to the grid. It This was not continuous, it discharged for a few seconds then we'd import a bit before switching back to exporting again. This continued until the battery reached 20% then stopped.
Is this normal behaviour, as it seemed quite alarming to see my stored electricity disappearing?

I have a Solis hybrid inverter and Pylontech US5000 battery.

Any suggestions gratefully received.






Many thanks

My hybrid inverter does this too. Its how the software is written I think. It can be worse than it appears as my app doesn't update more than every 5 mins. So it looks like it exporting a lot but it's not. This one threw me when I started out and tbh I'd like to be able to 'tighten' it up but on my Goodwe units that's not an option.
Congratulations on the new battery.

Hopefully someone who owns a Solis inverter will be along soon.
BTW, I am talking about 50 to 150W in and out for a few seconds. If you are exporting 2.27kW unasked then there is defo an issue.

[JohnW]

Thanks Joeboy, I'll get the guys that installed the system back, but I don't have much confidence in them!

[MrPablo]

Hi JohnW, good to see another Solis owner!
I might be able to help, but first question for you - do you have a tariff like Octopus Go where you charge from the grid, or is this entirely solar charging?

[richbee]

I finally got my first battery fitted last week and on Thursday it charged to 86%. However, as the sun set, the battery started periodically exporting to the grid. It This was not continuous, it discharged for a few seconds then we'd import a bit before switching back to exporting again. This continued until the battery reached 20% then stopped.
Is this normal behaviour, as it seemed quite alarming to see my stored electricity disappearing?

I have a Solis hybrid inverter and Pylontech US5000 battery.

Any suggestions gratefully received.






Many thanks

My hybrid inverter does this too. Its how the software is written I think. It can be worse than it appears as my app doesn't update more than every 5 mins. So it looks like it exporting a lot but it's not. This one threw me when I started out and tbh I'd like to be able to 'tighten' it up but on my Goodwe units that's not an option.
Congratulations on the new battery.

Hopefully someone who owns a Solis inverter will be along soon.
BTW, I am talking about 50 to 150W in and out for a few seconds. If you are exporting 2.27kW unasked then there is defo an issue.

Can you see the overall stats for the day - to see how much has actually been exported to get a feel for the size of the problem? I get bits exported from mine when it swaps from high to low demand, but it doesn't add up to much normally

[Moxi]

John,

The inverter shouldn't be exporting back to the grid like you show in the pictures and I suspect (Like Mr Pablo) that the settings are not correct for your set up.

First off can you tell us the model number of the inverter so we can determine if you are AC or DC coupled - looking at the pictures I think you are DC coupled but it would be best to get the model number to confirm this.

Next are you charging the batteries just from solar or do you have an electric tariff that allows you to benefit from charging with cheap rate electric during the early hours of the morning ?

What should be happening is that as the sun sets your battery starts to feed the house load and as you switch on or off loads there may be a momentary excess import / export as the control system catches up with the change in demand - this really should be no more than a few tens or hundred watts for a few seconds in most cases.

If you can provide the detail to the questions above then I think we should have this sorted for you quite quickly (wheres the fingers crossed emogi?)

Moxi

[JohnW]

Hi JohnW, good to see another Solis owner!
I might be able to help, but first question for you - do you have a tariff like Octopus Go where you charge from the grid, or is this entirely solar charging?

Hi Mr Pablo.
I currently with British Gas on their standard capped tariff, but wanting to move to Octopus. Currently, the battery is charged just from the solar panels.

Cheers

[JohnW]

John,

The inverter shouldn't be exporting back to the grid like you show in the pictures and I suspect (Like Mr Pablo) that the settings are not correct for your set up.

First off can you tell us the model number of the inverter so we can determine if you are AC or DC coupled - looking at the pictures I think you are DC coupled but it would be best to get the model number to confirm this.

Next are you charging the batteries just from solar or do you have an electric tariff that allows you to benefit from charging with cheap rate electric during the early hours of the morning ?

What should be happening is that as the sun sets your battery starts to feed the house load and as you switch on or off loads there may be a momentary excess import / export as the control system catches up with the change in demand - this really should be no more than a few tens or hundred watts for a few seconds in most cases.

If you can provide the detail to the questions above then I think we should have this sorted for you quite quickly (wheres the fingers crossed emogi?)

Moxi

Hi Moxi
Hope all is good with you and the family.
- The inverter is a Solis S5-EH1P3.6K-L
- I'm on the standard British Gas capped tariff at the moment
- The battery changes just from the solar panels.
- The exporting from the battery was a few seconds at a time but was happening several times a minute for over an hour, by which time the battery had discharged to 20%

Cheers

[marshman]

Do you have a "diverter" to send excess PV to your domestic hotwater tank immersion heater?? If so it may be "fighting" with Solis inverter.

[JohnW]

Do you have a "diverter" to send excess PV to your domestic hotwater tank immersion heater?? If so it may be "fighting" with Solis inverter.

Hi Marshman. No we don't have anything as sophisticated as diverters. Just a basic PV and battery system