FoxESS Community - Owners & Installers Forum

Ovo / Greenspace Solar completed an 8 solar panel installation on 18th December. It includes 1x FOX ESS EP12 (11.52kWh), 1x FOX 1ph 5kW Hybrid Inverter. It was sold to me as having a reduced rate overnight battery charge from Ovo but on the 18th December Ovo emailed me to say the off peak charge was no longer available.

I am trying to understand how the Fox controler works. It is set on Self Use Work Mode, system min SOC 10%, 10% battery reserve capacity and grid chagre time off. I appriciate panel production is low but the system has exported to the grid when the battery is only 38% charged. It has imported even when the solar input is occuring. The battery reserve droped to 8% last night but then charged on two occasins overnight so it is now 38%. In my mind it only needed to charge to get the battery to 10% and then just meet demand from the grid. I have times when I am buying at 24p and selling to Ovo at 20p even when the battery is less than 50%
I have reported the matter to Greenspace who are investigating.
Can anyone tell me what the system should do on Self Use Mode.
Do I have the facility to see the settings and change them beyond the 4 control settings?

Much of what you described suggests the batteries are cold, as you say when they fall below minSoC you would expect to see a small amount of power charging to get them above 10% (usually overshoots by a % or 2), but when very cold the battery protection steps in and the charge level increases in an attempt to warm them.

Your batteries should have heaters on board, have you enabled them ?

Can you post your inverter and battery firmware versions, there have been a number of posts recently about cold handling and lack of heater functionality and the latest firmware is much better than previous versions.

Under normal conditions Self Use is all power generated from PV is used to cover house load first, and left then goes to the batteries, if the batteries are full (or too cold to accept charge) the power goes to the grid as export.

When there is no solar and your batteries are above minsoc they will cover house load, when they reach minsoc they will cut off and power will come from grid - As the inverter and batteries are actually powered from DC (i.e. PV or battery) at night they continue to take a small amount of power from batteries and you typically see the battery do small charge cycles every hour or so to maintain minSoC.

It’s usually best to make sure you charge the batteries as much as possible during a low tariff, to ensure you don’t draw power at a higher tariff (unless you have a single tariff).

December / January usually the worst months for solar, once the suns elevation is high enough you’ll charge your batteries from solar.

Hi Thanks the quick reply. Yes it has been very cold which may explain my problems.
To deal with your points
I do not know about battery heaters- How can I tell if I have them and how would I switch them on? Would it be usual for them to be fitted in the UK?
Battery Device Information
State：Normal
Master SN：60EP6120597Q174
Slave SN：60EP6120597Q174
Plant：
Model：EP12
Associated Inverter：605H5020593A011
Version_BMS：1.011

Inverter Device Information
State：Normal
SN：605H5020593A011

Model：H1-5.0-E-G2-WL
Datalogger：605H5020593A011
Version_Master：1.47
Version_Slave：1.04
Version_ARM：1.35

When I acepted the quote it included an off peak battery charge. The day it was fitted the supplier emailed and said it was no longer doing off peak battery charge with effect from 1st Feb. I am looking at changing suppliers but Ovo seem to do the best buy in rate.
I hope this helps

In the Fox Cloud 2.0 App, under Quick Launch look for "Battery warmup" if you do not see this choice, then press the edit button to the right of the Quick Launch, and add the tick to battery warmup, if this is greyed out, then you need a Firmware upgrade on your Inverter, so that it is aware heater is a choice.

The latest FW for battery heating is 1.011 that you are running already, so that is ok. And AFAIK all EP12's have heaters.

Hi
Where do I find Quick Launch please? I cant see it in Dashboard or settings. I have not been given any instruction in using this !!!

Fox Cloud 2.0 is an App you get on your phone/tablet from Play Store or Apple store.

Video from Will


A small video from me where you see the heater animation, so you know it is working.
viewtopic.php?p=10871#p10871

You won't need to follow this video, but you can see a nice overview of the Fox Cloud 2.0 App here direct from Fox themselves.

Hi Great Thanks. I battery warm up switch was OFF!
turned on and temp set as per video.
Tried to set the grid time settings was able to change time and hit subit got tjhe OK but the slider switches wont slide to the right to switch on.
Unfortunatly I have to go out now so I will have to deal with this latter but thanks som much for your help.
If you can reply I will deal when I get back
Thanks again
Peter

Are you struggling to get the grid charge setting of the heater to stick?

The App itself isn't usually a problem, the speed of the Fox Cloud website/the in home WiFi signals can cause you general trouble setting values, a pull down from the top of the screen can force the App to refresh.


Just a heads up about the heating that is a current problem even on your 1.011 FW, when it heats up, you will find that it cannot discharge for some people (maybe everyone.) We are hoping that this gets fixed ASAP, it's also causing some inverters to go into a boot loop too it seems.

Hi it worked. Thanks so much for your help.Peter