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

Ron-ski · 24 Aug 2022 at 20:35

I asked Fogstar for the EVE test data spread sheet last night, they emailed it through this morning.

My cells range from 290.6 AH to 294.1 AH, if that is the case it will give a 15kWh battery. Once I get my battery tester I will test some cells.

The only odd thing is the spreadsheet has a production date, and creation date value for each cell, all of which are the 15 June 2022, which differs from what the Lifepo4 app says, which is January this year for most of them.

Troop said:
Hydraulic Wire Crimper, next on your list of stuff to buy, it never ends!, if you don't have one already.
I'd go the 16Ton version for the longer length handles, makes crimping a bit easier, you still have to use all your strength
A lot of crimping to do.

I didn't, I do now though, it arrived yesterday

Only the 8t one though.

Last night I ordered all the aluminium for my solar mounting brackets.

Ron-ski · 24 Aug 2022 at 20:47

Gym, what's the gym??

I'm sure I'll be fine, as long as I don't do too many at once.

PS Over 30 years as an HGV fitter helps, but I'm getting older now and not on the tools so much.

Ron-ski · 27 Aug 2022 at 00:02

Some aluminium arrived today, 36kgs of it.

Ron-ski · 27 Aug 2022 at 22:47

Journey said:
Are you designing the railing system/mounting solution yourself, or something you have seen elsewhere?

Designed it myself, and will build it myself. Aluminium equal angle 50.8 x 3.2mm, rubber blocks under aluminium pads bolted through the roof, and plenty of polyurethane mastic, although the rubber/ally pads should provide an effective seal, its always good to use some decent mastic just to be sure.
Idea is to keep the height of the panels below that which is required for planning permission.

Well that was a long hard days work, but my brother and I have successfully installed the two cables, still have some internal tidying up to do, then just a trench to dig and get the cables into the garage. My 43 meters of 25mm SWA actually turned out to be just over 50 when we measured it, so plenty of cable.

Ron-ski · 28 Aug 2022 at 21:00

Another successful day, tidied up all the cables in the utility room, run in some 10mm T&E for a future induction hob (currently gas hob), tidied up the cables down the wall, and under the oven. Also cemented around the SWA where it goes through the wall.

In the below picture in the foreground is the 25mm SWA in and out, then the kitchen ring main, 6mm T&E for the oven, and the dark grey one is 10mm T&E for the hob. This is all hidden by a 300mm wide pull out unit.

This is the cables running across the back of the utility room, this area is covered with a 3mm steel plate, the gas pipe used to run along there as well, but that was removed a year or so ago, and now enters via the kitchen. Its a pain using cable clips on thermalite, I actually drilled out the cable clips and use 2" nails, then they stay put. Sometimes you can nail them into the mortar joints. The white pipe is the condensate drain from the boiler.

Tomorrow I just need to put the fridge freezer back in the utility room, and put the baskets back in the pull out unit. Then its a day off. Next weekend I'll start digging the trench to the garage.

Ron-ski · 3 Sep 2022 at 17:47

Well that was extremely hard going, rock hard clay soil, numerous stones, the odd house brick and concrete block, also hit the foundations, as they were laid in the wrong place when the extension was built, but at least the trench up to the path is dug.

Tomorrow I just need to dig under the path and the pit the other side of the path by the garage, then drill appropriate holes through the concrete foundation of the garage.

I should have enough SWA left to run a piece back from the garage to the wall top right of the picture, which is the most likely place an ASHP would be installed if we ever got one.

Ron-ski · 4 Sep 2022 at 15:04

I've got the pit between the path and garage dig quite easily, even the tunnel under the path wasn't too bad to do.

I'm on to the really difficult bit now, drilling 30mm holes through 400mm of concrete, poor old SDS drill is getting rather hot. Got one through, need to drill at least one more, but then I need a hole for the network cable, and also potentially another for the cable for the ASHP. No idea if we'll ever install one but just seems sensible to put the cable in whilst the trench is there.

Ron-ski · 4 Sep 2022 at 15:10

Not for the 240v, I will for the data cable though.

If I put a duct in for the power cable I would need a diamond core bit to drill through the garage slab.

Ron-ski · 4 Sep 2022 at 22:35

Yes, I've been in contact, sent pictures and spoken to them, I'll update them with progress tomorrow.

Ron-ski · 5 Sep 2022 at 13:47

@Troop it would be a solution, but still with issues, the garage floor slab projects 120mm from the base of the wall, and to get the bend radius on the SWA I would have to cut the concrete out, which is doable and I do have a petrol cutter with diamond blade, so could have done that,

@SBo 6mm wouldn't be enough, given the length, there would be too much voltage drop for solar (even doubling up the cores) I'd much rather play it safe with a nice chunky cable, remember the whole house will be running through it

Two holes are drilled, just need one more at 30mm, and one at 20mm for a network cable.

The additional extra 30mm hole isn't really required, it just makes future installation of an ASHP easier.

The 25mm SWA also easily allows for the required cable derating - 25mm can handle 134 amps, so plenty of scope for derating.

Ron-ski · 5 Sep 2022 at 15:38

That's the electricians domain, so currently I have no idea.

Ron-ski · 10 Sep 2022 at 17:57

I drilled the others holes during the week after work.

Today I got the cables all in, and the pipe for the data cable, unfortunately my warning tape hasn't arrived so can't fill the trench completely.

I used bits of old garden canes as stakes to separate the SWA, which was bedded in sand, then covered in sand, followed by soil, then cut paving slabs (had them spare so why not), then some soil, then should be the tape once it arrives.

I've got a sign to go above the cables where the enter the concrete slab, but this bit between the path and garage will be dug out eventually and filled with decorative stone eventually.

My old Stihl cut off saw - bought this with a knackered engine in the mid 90's and rebuilt it, its been very useful over the years.

Starting on the left below is 20mm pipe for network cable, then 25mm SWA for potential future ASHP, 25mm SWA from the grid/meter, lastly 25mm SWA back to the consumer unit.

The above cables are not tight against the wall as I will build a stud work frame, with ply, and then cement board for fixing everything to.

Ron-ski · 13 Sep 2022 at 19:27

Waiting on quite a few bits, but then I've still got loads to order/organise.

I'm going to spend the day at work Saturday making the mounts for the solar panels, and I've also got the steel to make the sides of the battery rack.

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.

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.

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