FoxESS Community - Owners & Installers Forum

Hello everyone. Just installed a 10.5kh, 1 x 4300 master and 2 x 4300 slave. What a brilliant system! Absolutely towers over my old solis and lv5200 batteries! I cant believe the difference. It draws much more from the same panels (struggled to hit 3kw even in middle of summer yet over the last few days constantly hitting 3.5kw off less than 5kw worth of panels). It just seems to be so much more efficient. I have little solar knowledge but it almost set itself up! Very happy with it. So, it is constantly drawing between 1 and 15w. Some sort of reference signal maybe? It took 2kw from the grid over 5 days, with a lot of sun and full batteries. Just wondered why its doing this. And, are the lights on the slave batteries supposed to be flashing, and also the slave light on the master is flashing? The lights on the master flash until fully charged but the slave lights just carry on flashing no matter what. Is this correct? Thank you.

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.

Your old system would have been doing the same to some extent.

Regarding the lights, can you be more specific about colours / frequency / etc of the flashing?

Hi Callum, the lights are all green. Flashing maybe once a second. All the lights on the master, are solid green as its fully charged, except the one at the bottom marked "slave", which is flashing. The light marked "master" is always solid. If a solid light means fully charged then why are the slave lights flashing? I dont know if thats the case as there are no details of what the lights mean in the manual. I am assuming if there is a problem, then a fault code would be showing but its says "normal" on screen. It all works great so i dont think anything major is wrong, its just a bit frustrating when i dont know why the master and slave lights seem to mean different things depending on whether they are flashing or not. Thanks.

Great, glad you have it all working, the KH is a great inverter

Green lights are good, what you are seeing is the master polling the slaves and each poll shows a flash, with a corresponding flash from each of the slaves, it’s a bit like a pack heartbeat.

As Calum said, grid tied hybrid systems have to synchronise to the grid and it balances itself which results in a very small power sample, but when it is exporting it won’t use any power as it’s biased the other way, so the more sun you have the smaller it will be. 2kWh over 5 days sounds about right.

Morning Dave, yes, its certainly a bit of a beast! Thanks for the explanation of the lights. The fox manual is great for installing and getting it running, but woefully inadequate when trying to find out what each setting does or what the lights mean! I guess this is where solar experience comes in handy. I am about to go through the vid Will made, where he explains each setting. I bought the LAN dongle and that was very easy to get to work with the cloud on my PC. I cant believe how little problems i had setting it up. I was about to buy the 4100s, until i got an email from the Fox UK accounts manager! How weird is that!? I sent Fox an email weeks ago, asking if any of their batteries were compatible with the 5200s. This was when i was trying to keep my solis. He asked me to phone him to discuss this. So, i had a very long and interesting conversation with a guy called Greg Hockin. I gave him the opportunity to finish the call a few times, but he wanted to give me his time and made sure i was buying the correct items for my situation. Just incredible really, given the state of a lot of customer services. He said they will stop making the 4100s very soon. So i changed to the 4300s! Also, the LV5200s were made specifically for solis. As solis do not make their own batteries, they asked fox to make some. You may already know this, but i thought i would mention it. Its turned out to be a very good move, ditching the solis and moving to Fox, mainly due to the info you gave, so thank you for the time you put in with me.

Glad you have it up and running, yes as you say the Fox user manual is more of an install guide, you have to work through the help available on here and the facebook forum ‘guides’ - so that’s another learning curve

When you are in contact with Fox directly they are usually excellent with their advice and support, but obviously very, very busy.

Thanks for the info on the 4100’s, I didn’t know they were being withdrawn - I can understand them not wanting to tell people about these things, but it’s a big investment and you have to get your capacity right from day 1 … which rarely happens.

I cant remember the reason why he said they were stopping the 41s. He was giving so much info, its difficult to remember everything he said! He seemed to be quite excited about talking batteries! lol! But it was nice to hear someone that obviously loves the job he is in. I know he said there wasnt a reason to keep them as they have 29s and 43s, and the 41s are just too close to both. I have said this before, but i am absolutely stunned by how good this stuff is. I only have my previous system to compare it to but its the same panels. I am getting so much more power from them. I know you saw my fb post concerning the lv5200s and springwell electrics having a shipment coming in of them. I am so glad i bought the fox stuff before Liam sent me that text! I really dodged a bullet there!

It's definitely not a good thing that invertors require a small amount of energy from the grid. Here in Germany, we buy energy at 30 cents and sell it at a fixed price of 8.6 cents.

I can sort of understand why its done though. I can switch the grid off altogether if i wanted to and not have that slight draw. Which is obviously the end goal. If i did have a power cut, which i simulated when i first set this up, it switches straight to EPS. As i have my whole house powered by EPS, all i saw was a cut in power for less than a second, then it all came back on. With my old solis, if i lost the grid, i would have to physically go and set the solis to off grid mode. Its a brilliant machine, the 10.5kh, so i guess i have to make some compromise and accept the slight draw if i want to keep the grid connected.

So the way fox have developed their on grid inverters is so that it's grid synchronised. If you turn on a high load like an oven or kettle it would make LED lights flicker until the battery catches up with the new house demand. With the inverter always pulling 20-40watts its able to perfectly balance demand and battery response without you seeing any odd issues with sensitive lighting or eletronics. I work around this by starting each day with a full battery charged at cheap rates so my inverter is exporting by 9am and I don't have this tiny draw as I'm exporting something nearly all day.

Will wrote: ↑Fri May 10, 2024 9:00 am So the way fox have developed their on grid inverters is so that it's grid synchronised. If you turn on a high load like an oven or kettle it would make LED lights flicker until the battery catches up with the new house demand. With the inverter always pulling 20-40watts its able to perfectly balance demand and battery response without you seeing any odd issues with sensitive lighting or eletronics. I work around this by starting each day with a full battery charged at cheap rates so my inverter is exporting by 9am and I don't have this tiny draw as I'm exporting something nearly all day.

I stick to incandescent bulbs on the whole but there are a couple of LEDs in the front room where my pc is. I always wondered why they flickered slightly when i switched on my pc. That was with my solis. I havent noticed it doing it since i got the KH but obviously the lights go on much later this time of year. I think i will test it tonight! Thanks, Will.

Exactly, the KH will keep the voltage flat so you won't notice any voltage peaks and dips.