Ronski's Solar & battery DIY build with whole house backup

Ron-ski · 17 Sep 2022 at 22:33

Got all my aluminium cut for the frames today. Didn't get as much done as I'd hoped, but had some complications - got called out on a breakdown that took about an hour, at least I was at work already.

Seems my measurements and cutting is pretty much spot on

I also primed the frames, they will be sprayed black, only really needed to do the end ones, but did the lot.

Was hoping to get a start on the battery rack, but that didn't happen, I've got the steel, just ran out of time. I've got the drawer slides/runners on order, they should be arriving Tuesday, each pair can take 100kg.

The warning tape arrived - both lots as I ordered some more, so I can get the trench filled in tomorrow.

PS Think I've got some sweeping up to do Tuesday.

HungryHippos · 17 Sep 2022 at 22:54

Looking good!

Ron-ski · 18 Sep 2022 at 17:05

Finally got that trench filled in.

Hard work compacting the soil down.

But it paid off, as there was not much soil left over. I sieved the remaining soil, which will be spread over our flower beds.

Troop · 18 Sep 2022 at 17:21

The hard work looks done now; you'll soon be there.

Old Eberspacher set up in the garage for heat.....new man cave is born.

Eying up those nice slate slabs you have there

(be a nice base for the steam engine I'm building)

Ron-ski · 18 Sep 2022 at 17:40

Yes its coming along nicely now, still need to sort the garage out, going to move some cupboards around to make more room on the solar wall.

Slabs are Marshalls Symphony Black Porcelain 600 x 300, bought 30m2 of slabs off Marshall's factory outlet on eBay when I did the back garden back in 2018, all my own work including knocking out the hole and installing the bi-folds.

Ron-ski · 19 Sep 2022 at 15:06

When I bought the SWA at auction I also bought a 100amp switched fused unit, but along with that was to two 17 edition plastic consumer units, and a couple of other bits which I was going to eBay. But last night it occurred to me I could use these two CU's as solar combiner and fuse units for my 4 strings.

So I've ordered two 250mm long DIN rails and the following to convert them to my needs, hopefully I've ordered the correct bits.

Ron-ski · 20 Sep 2022 at 20:28

My battery rack slides arrived today, certainly seem well made, each pair weighs 3.5kg, but then they are rated for 100kg a pair, they have a slight over extension, which will make working on the cells easier.

Ron-ski · 25 Sep 2022 at 18:26

Weekends progress, plywood will be faced with cement board, so its not flammable.

Only had to buy two long vertical studs, the rest I had, so that cleared a little more space as well.

SWA is just screwed up temporary to get it off the floor.

Ron-ski · 29 Sep 2022 at 20:41

Just found the Victron Toolkit App, looks useful for calculating voltage drop for the battery cables

Troop · 29 Sep 2022 at 22:00

Any more of your gear arrive from CN?

My EVE LF280k's arrived today, not bad really 6 weeks from ordering on the 16th of August.
Dodged a bullet with buying them before the pound tanked.

Ron-ski · 30 Sep 2022 at 13:16

I've had some circuit breakers arrive, and just had notification that three orders have arrived in the UK

Are your cells all ok, and the twin bolt or single stud type?

Troop · 30 Sep 2022 at 13:49

Ron-ski said:
I've had some circuit breakers arrive, and just had notification that three orders have arrived in the UK

Are your cells all ok, and the twin bolt or single stud type?

Yes, cells are all fine, single stud fitting, just waiting for more 25mm quare cable and I can start another battery build.
JK BMS and all the other gear has been here since the summer.

Just need to wire up the cells/BMS and connecting up to the Victron smart shunt that the other battery is connected to.

Ron-ski · 2 Oct 2022 at 18:03

Some more progress.

In the virtual world.

And in the real world.

katie279 · 2 Oct 2022 at 19:03

Looking good Ron-ski - some space there for extra batteries too when you choose to upgrade....

Looks really neat thus far, looking forward to seeing your cable management solutions! Don't know if you're already equipped with 3d printer - these are a godsend for this sort of thing as you can easily make custom cable mounts, holders etc to perfectly suit. If you're not, but do reach out if anything I can help with - happy to design, print and send anything....!

Ron-ski · 2 Oct 2022 at 19:11

Thanks, they certainly are, I have an Artillery Sidewinder X1, but I do need to fix a leak on the print head, been extremely useful since I got it.

The rack has space for four batteries, so about 58kWh, although it's unlikely I'll have four but possible. I expect once I've got the main expense out the way and everything is up and running I will add another. There is space for another MPPT as well, just in case I add more panels in the future.

Cable management is going to be a bit of a headache, but I'm starting to form some ideas, but will need to check some things with the electrician.

Troop · 2 Oct 2022 at 21:22

@Ron-ski

If you are going with the Linx busbar system (as in your pic), the best option is to go with the Gerbo GX to tie it all together.
The raspberry PI, Venus OS works great but more for DIY busbars and such.

It will be a cracking system when it's all up and running for sure.

Ron-ski · 2 Oct 2022 at 22:21

I was looking at making my own busbar setup, but then I thought actually the Lynx set up would fit quite well, and then just run a pair of cables from each battery tray when I add another battery.

Not sure yet on the Gerbo GX, but it may be simpler in the long run.

Ron-ski · 3 Oct 2022 at 20:09

Got some more parts arrived today, battery/cell tester, panels clamps, and electrical parts for the combiner boxes.

Unfortunately the clamps are wrong they, they sent 35mm and not 30mm clamps.

The parts below were ordered on the 19th September from China, I ordered a couple of bits of DIN rail from the UK the next day, but that has still not arrived

Should also have the aluminium for the bottoms of the rack drawers tomorrow.

SBo · 6 Oct 2022 at 19:00

I'd be really interested in what your spark says about both earthing and also isolation from the supply. Hopefully he has a copy of this https://shop.theiet.org/code-of-practice-for-electrical-energy-storage-systems-2nd-edition (I don't).

1. Earth is reasonably straight forward - earth rod in addition to the supply earth with the appropiate (low) impedance. For you I think that will mean having to export the supply earth to your outbuilding in addition to having a rod.
2. Isolation from the supply seems to be more complex, live is generally disconnected by inverters and you don't want to be switching it again or your inverter won't know when the supply is back on, but you are also supposed to disconnect the supply neutral and so you then need to bond neutral and earth upstream of that and do so mechanically so that it disconnects itself again when you go back to grid. The powerwall does this (insturctions below). I don't understand the point of the disconnection tbh, they won't want any risk of you feeding current back down either line conductor but with a PEN supply the neutral/earth link in the cut-out will just put the supply neutral back at the same potential difference that it would be at without isolation, and you are not required to disconnect the supply earth when islanding. Keen to learn more.

Page 25: https://www.tesla.com/sites/default...wall_2_AC_GW2_UK-EN_Installation_Manual_0.pdf
Quite a bit here: https://engx.theiet.org/f/wiring-and-regulations/25149/battery-backup-earthing---pme-supply/109663

Ron-ski · 6 Oct 2022 at 19:52

@SBo He did mention something about requiring an earth, but to be honest that's all above my head. I'm getting close to the stage where the house consumer unit can be replaced and a new garage one fitted, and the supply routed through the garage, not sure if he'll want to do that first then the solar inverter side of things later. I'll ask him next time I speak to him.

Here's a block diagram of the Quattro, from what I understand it will disconnect the incoming grid in a power outage. AC in 1 is the grid, AC in 2 could be a generator, but I've no plans for AC2 at the moment.