Help with battery choice

cheesymouse

I have a house with a 3.9 kWp FiT PV system. We are about to start major renovations and as part of that will be installing an ASHP and UFH to replace an LPG boiler and ancient radiators. Now would seem to be the right time to add a battery, and possibly replace the old solar panels and increase the PV generation. 

I have read extensively around the subject of renewables, and learnt a lot from this forum as well as countless YT videos over the last couple of years. I’ve probably spent way too much time thinking about this and need help to finally come to a decision on which battery (and panels) are the right choice, when considering ethics, installer and battery. Keen to get real world insight from Givenergy, Sigenergy, Huawei and Tesla battery owners. 

Installers I’ve spoken to so far are keen on Sigenergy, but I get the feeling that the installers like them as they are easy for them to install! Local electrician likes Huawei, I’m not finding installers keen on Givenergy, and Tesla because @Screwdriva is such a fan.

I should add we have 2 electric cars and need back up as we are rural and get power cuts.

Any advice will be much appreciated.

Screwdriva

It's no surprise that Sigenergy is so popular with the lower tier of installer - the company has next to zero quality standards when selecting who offers their product (lots of Cowboy outfits) unlike Tesla, which requires company level certification, including solvency checks, RECC etc.

Whereabouts are you located?

cheesymouse

Thanks, I’m in the South West

NedS

In my experience, once an installer has become Tesla certified, they tend to install little else, probably because there is enough demand to sustain that. My local installer (relatively small installer) was holding significant stock of PW3's to ensure they were able to keep up with demand so must have good confidence in the product.

Sigenergy systems seem particularly popular with installers because they are modular and therefore easy to physically install without any additional heavy lifting equipment (the Tesla PW3 trolley lift is quite expensive). On paper they stack up well (no pun intended) against the Tesla Powerwall, but they do not have the 10 year product history and 1 million unit installation base that Tesla has behind it. I must admit I do like the look of the Sigenergy offering, and would be happy to consider it from a trusted local installer prepared to back up the product (given it's lack of history)

The Tesla PW3 met my needs perfectly, ticking all boxes, so it was pretty much a no-brainer and I was very happy with the attention to detail and high quality of installation from my trusted local installer (with a 15 year plus history).

thevilla

If I was buying again, I'd look for something modular so that additional capacity could be added cheaply. Our GE all in one doesn't last all day since we installed tha ashp but adding a second aio is prohibitively expensive. No problems with our battery but GE get a slagging in forums etc.

Screwdriva

https://forums.moneysavingexpert.com/discussion/comment/81878880#Comment_81878880

Re: Sigenergy, you're alot braver than I am

https://www.solarquotes.com.au/blog/sigenergys-terminal-problem-burnt-plugs-throttled-inverters

One other thing most end users are unaware of is that Sigenrgy battery inverters use internal DC optimizers - all is well while they are running fine but should they fail, accessing them is another matter.

cheesymouse

Thank you NedS, thevilla and screwdriva for your input, lots to think about.
I have now contacted a couple of local installers and will get together some quotes for different battery options then go from there.

Magnitio

https://forums.moneysavingexpert.com/discussion/comment/81881413#Comment_81881413

You mentioned Huawei. We have their inverter and battery which we are very happy with and their forums aren't full of complaints, unlike some alternatives. I would understand why you might not choose this Chinese brand for political reasons, but equally, similar reasons might apply to Tesla .

cheesymouse

https://forums.moneysavingexpert.com/discussion/comment/81881936#Comment_81881936

Good to know you are happy with Huawei. I think I’m trying to find a balance between ethical, quality/reliability and price. Its a bit of a minefield!

EcoScruples

https://forums.moneysavingexpert.com/discussion/comment/81882083#Comment_81882083

did you make a decision?

cheesymouse

https://forums.moneysavingexpert.com/discussion/comment/81959775#Comment_81959775

I did, I’ve gone for Powerwall 3 and another 5kWp of PV. Just waiting for some building work to complete and then install can happen. I’ll come back and update when it’s up and running - can’t wait😁