Hello from (actually) sunny Hampton

[Stuart444]

First thing I notice is that there appears to be a CT around a cable just above the Voltacon box. Does that CT go round the whole of a T&E cable and what is the CT connected to?

You also have one battery connected to your inverter and the other batteries connected to the first battery. It seems normal convention to connect either the first or last to one pole of the inverter and the opporite battery to the other pole - someone more familiar with batteries can explain far better than I canat present.

Yes, you are right, I put the CT round the T&E I'd used. It was the only 6mm2 cable I could find in B&Q. I figured it was OK, but come to think of it, in its normal previous life it was round one incoming conductor on the feed from the grid before the splitter box. Daft of me! I've always wondered how these devices work so well given how crude they look. But as it's measuring the field round the wire, I guess putting it round live and neutral is going to mess it up. However, I'm 100% certain it's not exporting, as I expect the batteries to run down when we have a dull day (quite a lot recently despite the thread title!) and there's significant load like the washing machine / tumble drier. I've still got the car charging at night when I get cheap Octopus electricity. Tomorrow I'll split the T&E so that I can put the clamp on the live, and I'll charge the car in the day which pulls 7kW and see if it livens up the export.

Re the battery connection, this system works at 52v (so it's 12 lithium cells in series inside, maybe several in parallel too). Adding more batteries to increase the storage has to be done in parallel to maintain the bigger bank at 52v. You are right, the top battery will run at very slightly lower voltage than the lower ones due to the resistance in the connection wires, but they are hefty wire, even at 100 amps it will be small. I make a lot of model aircraft with battery power using much smaller lithium ion batteries, usually all cells in series but occasionally two strings in parallel. we bung 100A down conductors of maybe 10mm2 sometimes, and the strings are indistinguishable after full discharge. Voltacon definitely instruct them to be wired in parallel, I've seen that with these batteries on some of their youtube videos. So at least that bit is right, I think.

Thanks for your comment!

[Stuart444]

In that case welcome to the forum Stuart444 and could you please repost your introduction?

I can still see my initial post, but also still with the warning that it needs to be approved. So as requested, I've copied it and paste it below:

Hi all,

The sunshine outside is right now nice, but the power from my panels is going nowhere, so it's frustrating too. My story is a long one, but ends up with me having a fully installed DIY solar power system that itsn't working properly, and me not being on good terms with the vendor. Who isn't much help at the best of times, to be honest. So I'm hoping you guys can help me sort out the problem. I'm sure it will be something daft I've not noticed.

Hampton is in south Cheshire, near Malpas and Whitchurch.

I'm a retired chartered chemical engineer, I have lots of DIY experience but this is my first solar PV project.

My kit is:
16 off 400W or so panels, so max PV ~ 6.5 kW
Voltacon ESS 5.5 kW inverter (actually made by Voltronic, ESS510)
3 off PylonTech US5000 batteries
Eastron smart meter

I have an Kia EV6 with a 77 kWh battery, hoping to keep it topped up!

[Stuart444]

First, two minor points which won't affect the operation.

1) Your wiring diagram shows you have put the Eastron SDM630MCT-V2 within the DNO's equipment zone, they wont like that. It should be on your side of the Company Isolator. Maybe you have not drawn it correctly.

2) (what Countrypaul says), You have wired your batteries in the non recommended way. Because of the resistance in the connecting cables, your battery currents will be uneven, with the highest current flowing in/out of the top battery and the lowest out of the bottom battery.

If the power cables are arranged this way (see pic below) the current should be equal in/out of all your batteries. Which may mean you need a new cable as one is now too short but lets not worry about that at the moment, it will work as is.


Next, do you know what "operation mode" you have set the inverter up as ?, the manual has 7 operating modes, put it in the wrong mode and it won't operate as your expecting.

Next, do you know what "charger source priority" you have set the inverter up as ?, the manual has 3 modes.

Next, do you know what "Load supply source" you have set the inverter up as ?, the manual has 2 modes.

I note it looks as is you have a third party monitoring device, you say "Whatever load is being drawn by my house, the inverter exports nothing. I put a clamp ammeter on the connection from the inverter to the nearby consumer unit, and it usually shows 16W (0.016kW), dropping to zero if I open the isolation switch."

Again as Countrypaul noticed this - It also looks to me as if the clamp goes all around the whole cable (difficult to see clearly) but to work it must go around a conductor, usually the live conductor only. Is it as simple as this ?, maybe the inverter is working but you don't think it is because of a false reading in the third party monitor ?

Sorry, I'm struggling with operating this forum. Newbies! Who'd have 'em? I replied to Countrypaul and did see it, but can't find it now. Somehow I seem to have got this thread in the introductions section. Sorry if I've got that wrong too.


1. Yes my system diagram was wrong, my Eastron is after the company isolator. I've removed the diagram and will post a corrected one.
2. I'm sure that the battery packs should be wired in parallel, as I have done, not in series as you are both advising. It's shown that way on Voltacon videos, in the instructions for the batteries, and in the inverter instructions v1.1. However I've just read that the batteries should have the DIPs set to identify them, although the Voltacon instructions have diagrams of a similar but different battery to mine. Having said that, I've noticed a thread here on this topic, and the advice seems to be that it doesn't matter. Conflicting advice has been a common theme in this project! We can discuss later.
3. Yes, I realise now I set the clamp meter wrongly. I didn't think. It had been on my incoming conductor to my consumer units, showing us our instantaneous consumption. The clamp connects to a small transmitter and the display receives that, so the display can be remote somewhere where we can see it easily. I moved it in haste as I was ripping out hair! Tomorrow I'll split the T&E so that I can install it correctly.
4. It's getting late. I'll post all the setup values in the inverter tomorrow.

Thanks for your interest!

[AlBargey]

2. I'm sure that the battery packs should be wired in parallel, as I have done, not in series as you are both advising. It's shown that way on Voltacon videos, in the instructions for the batteries, and in the inverter instructions v1.1. However I've just read that the batteries should have the DIPs set to identify them, although the Voltacon instructions have diagrams of a similar but different battery to mine. Having said that, I've noticed a thread here on this topic, and the advice seems to be that it doesn't matter. Conflicting advice has been a common theme in this project! We can discuss later.

Hi Stuart, welcome,

The battery wiring as suggested by others is also the best way of doing it (bar using + and - busbars) the batteries are still parallel, but the main positive and negative are taken from opposing ends. If you're still unsure google image search for best way to wire battery banks. Or read Victron Wiring Unlimited.

I'm pretty sure you don't need to assign the dip switches with only a few batteries, I don't remember doing it for any install of Pylontech I've done, and they all work as expected logging correctly on Victron systems.

[nowty]

2. I'm sure that the battery packs should be wired in parallel, as I have done, not in series as you are both advising. It's shown that way on Voltacon videos, in the instructions for the batteries, and in the inverter instructions v1.1. However I've just read that the batteries should have the DIPs set to identify them, although the Voltacon instructions have diagrams of a similar but different battery to mine. Having said that, I've noticed a thread here on this topic, and the advice seems to be that it doesn't matter. Conflicting advice has been a common theme in this project! We can discuss later.

Neither Countrypaul or I are suggesting you wire your batteries in series, they are still in parallel. Its just how you take the positive and negative feed cables to your inverter to equalise the current to and from all your batteries. I thought the picture would help, we can discuss later if you don't quite get it.

EDIT - Albargey beat me to it.

[Stuart444]

Good morning all, from another sunny day in Hampton. So great to have knowledgeable people on my side

The sleep has done me good, and I realise now that the battery wiring you were suggesting was not to put them in series as I had thought you meant, but to keep them in parallel and connect the inverter to opposite ends of the string of 3 batteries. Yes, a better way! I had to cut the long leads from batteries to inverter to get in the fusebox, and as a result I can't get either + or - lead to reach from the fusebox to the bottom battery. I'm not too concerned about it for reasons I think I explained in a post that's gone missing, but I'll see if I can get a new lead.

I'll need several posts this morning as I have 8 photos to upload. Here are the first 3 after I modded the clamp meter. Hopefully I've got it installed correctly now and you can see it showed a flow of 595W when I took the pic. Unfortunately it can't detect the direction, and as shown on the 2 photos of the inverter's panel, that's not helpful either. (Sorry about the reflections.) The inverter's panel packs a lot of information, but import and export flowrates are not included. My billing smart meter doesn't give me a flowrate either, but the Eastron is showing about - (minus) 500W. I hope that means import, as the inverter is set to no export (see next post) and SPE haven't given me permission to export yet!

[nowty]

My billing smart meter doesn't give me a flowrate either, but the Eastron is showing about - (minus) 500W. I hope that means import, as the inverter is set to no export (see next post) and SPE haven't given me permission to export yet!

Turn on a high load like a kettle / toaster and see what changes on the Easton, that will let you deduce whether its import or export.

[Stuart444]

OK, now to the mysteries of the inverter setup. Here is a list of all the inverter settings that I now have.

The forum won't let me upload a doc, docx or pdf file. So sorry, it has to be screenshots.

[Stuart444]

Third post this morning. Here are some photos of my grid import to the property. I've posted them as the wiring is a bit of a mystery to me, and so my wiring diagram is a bit "assumed" here. You can see (bottom left) the incoming AC supply, going through the company fuse, then to a black box which has the billing meter placed tightly against it. I can't remove the lids of those as they are permanently live and I don't have a death wish. Then it goes to the company isolator, on to my Eastron, and then via a splitter to my two consumer units. I can't see any wires going into and out of the billing smart meter, so I'm assuming they are hidden by the close coupling mentioned as the meter does work!

[Stuart444]

My billing smart meter doesn't give me a flowrate either, but the Eastron is showing about - (minus) 500W. I hope that means import, as the inverter is set to no export (see next post) and SPE haven't given me permission to export yet!

Turn on a high load like a kettle / toaster and see what changes on the Easton, that will let you deduce whether its import or export.

Thanks! Yes, the kettle changes it to - (minus) 3.2 kW. So minus means import here.