FoxESS Community - Owners & Installers Forum

Hi,

I've just had a 12 panel array fitted, which I think is a nominal 5kW. A hybrid H1-3.7-E Inverter with EP5 Li-ION battery. At the same time I've had a EV Charger fitted (Apex not Fox) and bought a Tesla! Not to mention the Blink Doorbell so a lot to learn.

Firstly whoever set up, manages and replies on this forum deserves a medal. It seems a common experience that installers walk away with a general "use the App" and little additional guidance and are slow to respond to detailed setup type questions. So this resource is excellent and gratefully received. I've already found the answers to several issues (like why doesn't my BMS/Battery behave as expected? - Answer because its been consistently -2 C at night, options for insulation etc) Whilst the support for tweaks to setup have been a little slower, I have to say the system is working really well, generation higher than I anticipated and the installation very tidy, on time and cleared up afterwards so I wouldn't complain. However I now have two questions of my own.

My installer advised only to use V1 of the Foxcloud App, saying that they don't recommend migrating to V2.0 as "it's too buggy and unstable" is this correct it seems most people on here are using V2.0 - was my installer being over cautious? Is it possible to use V2.0 with reverting back to V1.0 as an option, or even running both Apps in parallel? I'm up and running OK on V1.0 and on the Website so should I make the change?

Secondly, I have read your answer regarding using off peak rate period for EV charging and to prevent draining the battery into the car by setting the battery to "Charge from grid" for the same period and that all makes sense. My concern is the total current draw this would create. I am on a shared supply with max current fused at 60A. On maximum the EV Charger is limited to 32A (ie a 7.5kW charger although this can be set as low as 5A which is one answer) and has load balancing which should protect the system where I have set a maximum 50A total load ie a 10A margin for other things switching on in the middle of the night, which would be another answer. What would the current draw be for the battery if it were unconstrained? I realise it varies with SoC but assuming it was at 20% what would the maximum grid current be to charge the house battery. If I wanted to constrain this to (say)18A how would I do this?

Thanks for the excellent help and I look forward to you helping me optimise my system

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Hi and welcome to the forum and the world of solar

The community was setup a couple of years ago exactly for this reason, there is also a very active facebook group here https://www.facebook.com/groups/foxessownersgroup

The V2 app wasn’t very good when it was first released and I think that is why installers were steering people away from it, but that is no longer true - the V2 app is very good and Fox have since announced that the V1 app support is withdrawn so I would strongly recommend you using the V2 app, it does so much more and well worth the move - it uses the same login credentials as for the V1 app.

There is also a 3rd party application called Energy Stats written by one of the members of these forums, many users find it much easier to use so i’ll put in the links here for you to look at if you are interested - If you have an iOS device you can get it here https://apps.apple.com/gb/app/energy-stats/id1644492526 or if you have an Android device it is here https://play.google.com/store/apps/deta ... nergystats

On the EV charging if your car charger is seen by the inverter as house load it will discharge the home batteries into the EV, this can be fixed with a bit of re-wiring which might need an electrician - but as you have said if you set a charge period at the same time as the car is charging it will not discharge.
As you have such a low main fuse, you can set a charge period but leave the ‘charge from grid’ switch disabled - when it is like this it will neither charge or discharge for that time period.

Your H1 3.7 will have a max charge rate of approx 3.4kW from grid (they can charge a bit faster from solar) so approx 16A to consider - you can throttle them by changing a setting but that would also slow the solar charge - however there is a way to ‘slow charge’ if needed at approx 1kW (approx 4A).

Thanks for the quick response, and the welcome! Certainly is a whole new world. I'll migrate to Foxcloud 2.0 as you suggesst.

The EV Battery v House Battery actually falls pretty convenient. 32A from EV charger + 16A Max from house battery gives me 48A, below the 50A limit where the EV Charger load balancer kicks in to reduce the EV charge, and well below the 60A house fuse. I want the battery topped off at night as I get no meaningful generation until about 11am due to the orientation so that suits me.

Thanks for your help, my only regret now is that perhaps I should have been more ambitious on system size, I could have fitted 4 more panels and a bigger battery. So I might be back for expansion/extension advice in due course.

Thanks for your help - and there's a few sunny days forecast in the UK now.

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