FoxESS Community - Owners & Installers Forum

Hi All, please can someone help me. I have a fox battery system connecting to x9 solar panels. The thing is sometimes the system exports to the grid even when the batteries are not full. Is there a way to stop exporting to the grid?
For example currently the batteries only have 10% and it’s exporting to the grid. Please help.

Is your work mode set to 'Self Use' ?

I can see you are using the V1 of the app - are you able to switch to the newer V2 app, that is much easier to use and you will be able to see the work mode at a glance.

The thing to mention is that the screen you are looking at is not real time, it's a snap shot of the data taken every 5 minutes - and if you have just switched off a large appliance such as a kettle, toaster, cooker or similar you get a split second of power going to the grid, and if the data snap shot catches it, it looks as if you are exporting to the grid when you are not it's just a sampling error.

Is your battery charging during the day as you would expect or is all of your export going to the grid ?

Hi Dave,

Thankyou so much for the help. A little background on my situation. I brought a house that already had 9 solar panels and an inverter that only exported back to the grid.

I then saved really hard and got the 9.5kWh Fox Ess battery system and it was connected to my solar panels.

The mode is set on ‘Self Use’ and what tends to happen is that the very rarely the battery charges above 15% and most often it seems like it’s feeding back to the grid instead of charging the battery up.

The way I would like to have the system is to only export to the grid when the battery reaches 100% full. This does not seem to happen and instead what I get is the battery feeding the load and then feeding back to the grid.

Do you think I should stop the system from exporting to the grid all together? Is this a safe thing to do?

I have just moved to V2 thankyou and tonight I am going to try for the first time to charge my batteries from the grid at 1am till 4am and my dual tariff has now kicked in. Let’s see what the system will do in the day time will it use the battery?

Many thanks
Much appreciated
Regards
MA

If the system is in self-use it shouldn’t be exporting to the grid at all if your batteries need charge, it charges the batteries first and then exports any remaining.

I think we need to go through some of your settings to make sure that it is working the way it should.

The first thing to check is in the battery settings, go to the Device, Battery tab in the V2 app - the time periods there unless they are being set to charge from grid should not have any value in them - if they are not being used they must be set to 00:00-00:00 with the ‘charge from grid’ disabled. (If there is a time entered with the switch set off, it instructs the battery not to discharge in that time period.)

The next thing to check is your Battery Reserver Capacity & System Min SOC - both should be set to 10% (ten).

If you can see the option for mode scheduler it should be set to ‘Disabled’

These are the more obvious things to stop the batteries charging which will ‘divert’ the power to export instead.

If that doesn’t work we may need to get a bit more adventurous with the inverter settings.

Can you tell me what account type you have (as that will guide me through the next steps) - in the V2 app if you click on ‘Me’ at the bottom, then click on the arrow next to the person icon at the top, it will show your User Name and Account Type - either User, Installer or Agent.

Hi Dave,

Thankyou so much for getting back to me. In self use mode it still trickles small to moderate amounts to the grid when it should be prioritising filling up the battery. I have checked the system and it has 10% on both soc and the battery reserve. The timer is set on 00:00 and the mode schedular is disabled. My account is set as an End user.

Will you be able to guide me to either to set the system up so it only exports to the grid when battery is full or may I should just disable the exporting altogether.

Many thanks
Much appreciated
Regards
MA

Can you post a picture of the power/energy flow from your app, the one that shows how much power is going where.

It looks like this

Hi Dave

Here is a current photo, many thanks

All grid tied systems will pull a small load from the grid in order to confirm it's still connected - if they can no longer draw that power, they shut down to avoid energising the grid and potentially electrocuting anyone working on the power lines.

At the same time, your inverter is constantly balancing how much power it's converting to AC from the DC power that comes from the batteries and panels, or if you have enough generation, how much of the DC from the panels goes to the batteries, vs going to loads or the grid.

If you turn on a large load, there is a split second before the inverter adjusts where power will be pulled in from the grid. Similarly, if you turn off a large load (eg when the kettle has boiled or the toaster pops up), the inverter continues to produce more AC than it needs to for a split second.

The data on the app is not real time - it's a snapshot of an instant taken at 5 minute intervals. This is enough to show the overall amount of power used, generated or exported, but it doesn't show the fine detail of the adjustments the inverter is making. If the snapshot coincided with the 200ms where the inverter was exporting 700W to the grid, you'll see that for 5 minutes until the next snapshot, and this can be misleading.

I log the grid power (coming or going) at 5 second intervals via HA on my H1 and it basically fluctuates +/- 20W, unless there is some large load going on or off.

I have a very similar issue so I have not generated a new post.
I have an installation which was installed about lunchtime today. Initially the batteries were about 50% and it is a nice day so they received from the grid until about 1 hour ago, when I set up the timers using the old v1 app because the v2 app will not allow me to set up the timers.
Now I am exporting to the grid and the battery is discharging at a small rate 54w the charge going out to the grid is currently .75kw but was 1.5kw on the previous refresh (5 mins ago)
Work mode is self use, mode selector is disabled, BRC and System min SOC are both 10%Charge time has two time jones which reflect my overnight cheap rate
23:31 - 5:30 charge from grid enabled and 5:31 to 23:30 charge from grid disabled.

I am using the latest version of the app v2 and I get """Perameter does not meet expectations""" when I click on the grid charge time settings screen - Whatever I enter in there gives that error.
I can only change the times in there if I use the older v1 app.

When I remove the time then the battery starts charging again as expected at this time of the day.

But I want the battery to charge to full overnight using my cheap rate electricity but as soon as I put times in the the battery stops charging from the PV system and I start exporting the generation again.

I’m not quite sure I understand the charge going to the grid, if you are generating solar power and the battery is full the solar would then be exported.

I’ll start with the charge periods, if we get those set correctly we can then see if there are any problems.

Using the old app you should set the charge period from 23:30-05:30 with charge from grid switch on.

The second charge period you have set should be deleted, that’s instructing your battery to ‘not discharge’ between 05:31 and 23:30 - it should be set to 00:00-00:00.

The V2 app has a problem with wrap around midnight times if you want to set 23:30-05:30 on that you have to set charge period 1 to 23:30-00:00 and then charge period 2 00:00-05:30

If you get your charge periods set up correctly, what you should then be seeing is the battery covering the house load until it reaches 10%,.

If you are generating solar it should first cover the house load, then charge the battery, then export to the grid (when set to self-use).