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

Soldato
Joined
3 Dec 2012
Posts
4,137
Location
Kent, much sunnier than Scotland
We already have 4kw of solar on our house roof, which was installed in December 2015, this is comprised of 16 panels witha Solaredge inverter and optimisers, and uses the best two roof's of the house.

As some of you might be aware on the solar thread I've been looking into getting an additional array installed on our detached flat roofed double garage, it will be 12 405w panels in an east west arrangement, the panel angle will be quite low at 10 degrees, this is to keep below planning requirements, anything over 200mm above the highest part of the rood and you require planning permission.

Garage_Solar.jpg


The mounting brackets for the panels are custom designed, and will be made by myself using 50 x 50 x 3mm angle. I still need to get up on the roof, and measure the pitch and allow for that in the design.

I will also be making a custom battery rack of my own design, it will have four pull out draws, each draw can hold 16 cells, and using 16 280ah cells makes 13.44kWh to 14.56kWh battery

Inverter.jpg


As this is a garage install I need to run a new sub main from the existing incoming supply to the garage, then a new sub main back to the existing, this will be using 25mm SWA, and will mean the whole house will run off the inverter in the event of a power cut.

Close up of the battery with busbars

Cell-Pack-with-Busbars.jpg


Oh, and yes I do have an electrician for the 240v AC work.
 
Been thinking of doing something similar so interesting to see what you are doing.

I've a smaller scale setup, but completely isolated from the main supply, with some 100ah gel deep cycle batteries - at 33Kg each the delivery driver was NOT happy - are those 280ah lithium? (EDIT: From the picture and maths I'm guessing they are smaller 3.2V rather than 12V 280ah which would be like 60Kg LOL)
 
I’m excited to see how this progresses. If you have a TNC-S electricity supply then beware the rules of earthing as they relate to outbuilding including garages. I mention since your house will effectively become a sub main of your garage.
 
any chance of putting up details of what parts you've ordered and from whom? Thinking of something similar myself and keen to find out what other people are buying, especially around cells, bms, etc.
 
@BUDFORCE Thanks, think I'm going to need it.

@Rroff They are EVE 3.2v 280ah LifePO4 cell's.


Are they the new K series?
I got 16 EVE LH280K delivered from china in 2 weeks for £1800 inc everything.
8 for my electric chair and 8 for a guy I know.

If they are the real thing. They will have the markings lasered in.

If anyone that lives near Solihull. I have 8 170AH cells to give away.
 
Shame they are about 4x more expensive than gel lead-acid batteries, there seems to be so many advantages to LifePO4.
They can be had for a lot cheaper than I paid from China, but you take your chances on what you get. They could be secondhand, a couple of year's old, or you don't get any cells at all, seems a bit of a lottery.
I’m excited to see how this progresses. If you have a TNC-S electricity supply then beware the rules of earthing as they relate to outbuilding including garages. I mention since your house will effectively become a sub main of your garage.

I understand there are some issues with earthing as it's a whole house backup, but that's the electrician domain, but I would like to understand it more. I know the DNOs earth cannot be relied on in the event of a power outage so a local earth is required, which probably means converting the house over to an earth rod.
any chance of putting up details of what parts you've ordered and from whom? Thinking of something similar myself and keen to find out what other people are buying, especially around cells, bms, etc.

I'll post up a list of what I've ordered later.

@deuse They are the ones with the double bolt hole per terminal. Yes, just check they are the K series. That was a good price, who did you use?
 
Looks a good project, would like to do something in future depending on how things go with some extra panels on my garage roof potentially west facing to spread load through the day but the cabling is set under my recently redone driveway, so would need to be something that could just plug and play.
 
They can be had for a lot cheaper than I paid from China, but you take your chances on what you get. They could be secondhand, a couple of year's old, or you don't get any cells at all, seems a bit of a lottery.


I understand there are some issues with earthing as it's a whole house backup, but that's the electrician domain, but I would like to understand it more. I know the DNOs earth cannot be relied on in the event of a power outage so a local earth is required, which probably means converting the house over to an earth rod.


I'll post up a list of what I've ordered later.

@deuse They are the ones with the double bolt hole per terminal. Yes, just check they are the K series. That was a good price, who did you use?

[email protected] Amy her name is.
Push for a good deal. And do it through email and not the site

 
I had initially planned on using a Multiplus II 48/5000, then ended up deciding to go large and use Multiplus II 48/10000 until someone on the main solar thread pointed out it's not G99 approved, which is a bummer as it has built in anti islanding, where as the Quattro 48/10000 doesn't.

Having emailed Victron this morning asking when it will have G99 approval I've just had a very quick reply from them.

The Multiplus II 48/10000 will be approved at some point but we don’t have a timescale for this, unfortunately

So I have two realistic options, use the Quattro and fit an external anti islanding relay, or use two Multiplus II 48/5000 in parallel. Space wise the Quattro would be better, cost wise the two Multiplus II might be better, also this would give some redundancy.
 
So I have two realistic options, use the Quattro and fit an external anti islanding relay, or use two Multiplus II 48/5000 in parallel. Space wise the Quattro would be better, cost wise the two Multiplus II might be better, also this would give some redundancy.

How much are you being quoted for the Quattro 48/10000 as is should be less than 2x Multiplus II's?
 
The cheapest I've found so far is a French ebay store. Multiplus II 48/5000 £1223, Quattro 48/10000 £2891


I do need to check Victron will honer the warranty, but I've heard they will.
 
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