Solar PV battery options

AC Coupled best option is the Sofar ME3000SP. Perfect with a DIY AliExpress cells linked to a Seplos BMS

The ME3000 is certainly silent

About £750 UK price, do you know of an Irish (or EU) supplier.

How much more would a 5kWh or even 10kWh DIY battery come to on top?

I see Midsummer in the uk are doing a combo on the Sofar ME3000SP & Sofar Amass GTX2000 including clamps and comms and power cables. link below. Will I still need to get the Seplos BMS separate? The 2.4 Kw system comes in at £1887.64 (including Delivery £78.00 and VAT £314.60) and the 4.8 Kw system comes in at £2784.60 (including Delivery £78.00 and VAT £464.10). Of course at the above prices u have to get it delivered to the north and collect it as god knows what extra import tax u could be hit with? Is there any wall mounted type battery's like the Sofar Amass GTX2000 or similar on Ailexpress that could be used with the ME3000SP. They look a lot neater looking job instead of the CALB 200ah 16pc but obviously a lot dearer.

https://midsummerwholesale.co.uk/buy/sofar-storage/sofar-me3000sp-amass-kits

Love my 4.8kw dyness. Very interested at that price....

Do please share the details when you find out.

There is a breaker/handle in between

Yup that's the same company I found the dyness 5.12kwh batteries, they are 1325 + vat.

Wonder what @unkel thinks of that price? 😛

Do you have any detail of that Battery? especially the model. I have the PowerDepot H5 version so maybe mine is not the same or compatible. That is certainly a price i would pay to extend my system from 5 to 10.

A BX51100 I believe.

Buy a 10 DIY and sell your 5 for a nice simple profit. Doubled your capacity free of charge

With all due respect, but @DrPhilG would admit to being quite tentative about taking it on and I have to say, he did a fantastic job. We gave him guidance when needed, but he was the one who did it and has no regrets (and possibly learned a fair amount about his system too.

it's all about being patient and mythodical. But very straightforward@DrPhil

Personally, I think the Sofar ME3000 route is a better bet

1. The ME3000 3kW would be in addition to your solar PV output.

2. You can control whether or when to charge batteries (maybe start car charging before batteries are full)

3. The ME3000 and batteries can be located in a totally separate location to your PV inverter.

4. A Hybrid Inverter is a single point of failure

5. Works beautifully with the Seplos BMS

6. Adding a sofar2mqtt device allows the ME3000 to be fully controlled by a raspberry pi running Node-Red or HomeAssistant

And also don't forget with the solis hybrid you can charge/discharge the batteries at 5kw not limited to 3kw which will cover things like hob/oven at the same time.

Are you a a DIYer ? Several of us here have built a 10kW DIY Powerwall for about €1500. You could have a separate Storage inverter connected to batteries rather than feeling that you need to replace the supplied Solar Inverter

For smaller systems how are people working out whether a battery will be cost effective and what size is worth it?

I've got a couple of quotes, one includes a huawei luna 2000 with a 5kWh battery which can be expanded and another with a dyness 2.4kWh battery which can also be expanded. Given the shape of the roof can really only install ~4kWp and our typically daily usage for the house is <9kWh, my initial gut is that 5kWh is unlikely to be cost effective. Especially as it looks like the huawei battery packs for the luna 2000 appear to be quite expensive at ~€3.2k per 5kWh. So even going without the battery initially and adding subsequently would be expensive based on the €1k per 2.4kWh rule of thumb I've read in the FAQ. Dyness batteries seem to be much more competitive at about €900 per 2.4kWh, so if it was worth going to 4.8kWh subsequently that seems like it would be the better option. However how do I tell if even the 2.4kWh option would be likely cost effective in the first place?

Looking at how the battery would be used, base on the solar performance spreadsheet I'm left with the impression that at 4kWp, Nov-Feb it would be a case of charging from the grid overnight as generally wouldn't generate enough during the day, and then consume it to supplement the solar. Mar-Oct though it looks like in general the power generated would be close enough to requirements that 2.4kWh would get us through any peak usage in the evening/morning so most of a 5kWh battery capacity wouldn't be contributing much. And it didn't seem like that Nov-Feb would be enough to have a larger battery pay back over time. But I feel like I'm just guessing here. Might have missed a guide in this thread as there are enough posts that I was skimming to see if I could spot something to help me understand.

What part are you unsure of. Seriously, go for it and we'll guide you through. It really is quite simple and straight forward.

The simplest way is possibly with 16s2p with then just a single BMS to manage the whole 20kW. When ordering two sets of cells, just make sure you also order an additional pack of busbars.

You can buy the batteries to inverter cable from any motor factors.

All you really need is a decent multimeter

Ok championc. You have convinced me. Thank you for the offer of support and maybe the project could benefit a few others on here. I'm not adverse to wielding a few spanners etc. but not very good on electrics but I do know what a multimeter is and have used it once or twice 🙂. So if you are willing to provide the technical information and assistance via this thread let the games begin... I have five initial questions:

Q1. Does it affect house insurance in any way beyond the value of the components?

Q2. What physical size is 20kwh worth of batteries?

Q3. What weight are they?

Q4. What are the spec / brand of batteries I should order / use?

Q5. Can you provide (maybe pm) links to where I can source the batteries, cables and BMS required (or whatever else is needed)?

BTW I have a 6kw Solis hybrid inverter for 6.9 kwp panel array. Currently I have a 5 kwh Puredrive battery, all reasonably accessible.

Again many thanks...if you are willing to coax me along 😎!

@Bif

I think Dr. Phil's post is right back near the beginning. Either he or someone else has deffo done a fairly detailed guide.

There are several on here who have gone the DIY route and I think a few are close to completion around now.

What you are looking for is the "CALB 200ah 16pcs" on AliExpress, from either PWOD or OYE. These are reputable distributors, as all recipients bought through them. Tax of 20% will be removed at checkout, they then come via Poland and land without any further charges.

The best bet for the BMS might be David Schad in the UK (via Facebook). It's possible that he can / should sell to you ex VAT and you then pay on arrival. Buying it from China is fast, but will cost about $50 for shipping and will get stopped for taxes.

Make sure you buy a USB to RS485 dongle / adapter with it.

And you'll likely sell your puredrive for at least €2k - so quadruple your storage for a few 100's

@rob1air

Don't buy inverters or panels abroad. If you have a company, try registering for a trade account with Midsummer.ie. Get your panels, mounts and inverter there. See above for the batteries and BMS

Loadshifting the extra 10kWh for 200 days per year saves about €130-€140, to give you an idea of the financials. That's based on a 9c difference between day and night rate (like on the better plans available today), but this difference could of course become much bigger in future. It already is on some plans, like the Energia EV plan.

Not all about money though, loadshifting is better for the environment too as already over 50% of all electricity generation in Ireland during night rate hours is from wind.

LiFePo4 should be 90% usable. I did take that into account in my calculation and the about 20% losses of battery cycling too.