Considering Additional Growatt Battery - supplier/installer recommendations

FlatFour

Hey all,

So, we have a 4.5kWh (10x 450w) Solar array on the roof, a 3.6KWh Hybrid Inverter and a single 6.5kWh Growatt Battery.  Pretty pleased with the system and its performance.  Our bills - we're electric only here, rural area - are substantially lower than they once were.  We actually tend to build a little credit in the summer, and that offsets some of our additional use in the winter.  Nice.

I'm currently considering getting an additional battery, or batteries, not quite sure how many in total my Inverter can support.  Some places say two in total, others say four in total.

Anyway, the company that installed the Solar have long since gone bust.  Lovely.  They were one of the top-rated (going by customer reviews) companies when we had our install done, but there were a few issues at the time.  I guess things went down hill after that.

So, what I'm looking for is a recommendation of a good company to advise, then supply and fit an additional battery (or more than one) to our existing set up.  I'm aware battery prices have dropped massively since I bought mine - like they're less than half the price now for just the battery - but I do need someone trustworthy to supply, fit and make sure everything is working properly.

I'm based in Oxfordshire, so while a local company isn't essential of course, someone who covers this area is.

I'd love to hear from people who've found a company they feel they can trust... it's a bit of a minefield out there.  Several "top" companies doing Solar seem to be no more.

Note: we try to self-use as much as absolutely possible, and have changed our energy use patterns greatly to take advantage of this.  We've even changed other aspect of the house, and how it uses energy to further support this.  Really pleased with the results.  I think a second battery would really help us stay self-sufficient a little longer in to the evenings.

Our single battery was full by 11:30 today - it's darn cold (-2c) here, but lovely and sunny.  Cooking, starting at around 4pm, will likely deplete a good chunk of that, with the battery likely running out (10%) not long after.  Based on energy usage patterns, an extra 6kWh stored would see us sorted for the night on days like today, likely seeing us with left over power tomorrow too.

I do think that self-use really is the way to get the best out of solar.  Don't have an EV - have a perfectly good 13 year old car - no plans to get one, so don't get the super-cheap night tariff or anything like that, just the standard flat-rate (same all day) unit cost + the irksome daily standing charge.  I know people who seem to rely on their daily export rate (while they're at work all day) to make their solar more cost-effective.  However, rates seem to be dropping or even going away entirely from what I've read.

Final thought: I'd love to have someone here who really knows these systems.  The installers, back in the day, weren't able to tell me much about them, how to tweak settings (like the 10% battery reserve level for example).  I could look it up myself, but I'd rather someone knowledgeable showed me.

Cheers.

QrizB

When was your current system fitted? What models of inverter and battery do you have?

Product lifecycles are sadly quite short, so it's possible that your current unit is already obsolete and the best option will be to replace it completely.

FlatFour

QrizB said:

When was your current system fitted? What models of inverter and battery do you have?

Product lifecycles are sadly quite short, so it's possible that your current unit is already obsolete and the best option will be to replace it completely.

A little under three years ago.  It's the 3.6kWh Hybrid Inverter SPH3600.  Battery is just listed as Growatt 6.5kWh, no further information.  Panels are Longi 450w.

Checking online, these units still seem to be available, but they could be revised models I suppose.

All is working well, and system is designed to be extended by at least one battery - I assume it depends on which batteries are already installed.

Oh, I did speak to one local Solar installer, but they don't work with Growatt.

Netexporter

If it was me, I'd look on Youtube for a video on adding an extra Growatt and do it myself.

FlatFour

Netexporter said:

If it was me, I'd look on Youtube for a video on adding an extra Growatt and do it myself.

It is very tempting, and I might indeed go that route.  However, I'd likely be invalidating any warranties doing so, as I'm not a certified solar installer.  The long warranties for Growatt stuff was part of the appeal.

QrizB

FlatFour said:

QrizB said:

When was your current system fitted? What models of inverter and battery do you have?

Product lifecycles are sadly quite short, so it's possible that your current unit is already obsolete and the best option will be to replace it completely.

A little under three years ago.  It's the 3.6kWh Hybrid Inverter SPH3600.  Battery is just listed as Growatt 6.5kWh, no further information.

On the plus side, the Growatt SPH-series hybrid inverters seem to use conventional 48V batteries. No weird and wonderful proprietary high-voltage systems.

Currently they seem to be supplied with either GBLI or AXE-series batteries. The GBLI batteries are the 6.5kWh ones (AXE are 5kWh) so I'd tentatively suggest that this is what you've currently got.

https://growattinverters.com/products/gbli-6532-battery.html

They're available for about £1000+VAT:

https://solartradinguk.co.uk/product/growatt-gbli-6532-solar-battery/

Sadly I'm not in a position to recommend a supplier or installer, but adding a second battery should be relatively straightforward for anyone who's familiar with hybrid inverters. It could even be DIY'd with care.

FlatFour

Yep, that's the one.  I actually found the same seller (solartradinguk) but they're out of stock currently.  If I were to fit it, I'd likely ask my friend (who's also our electrician, though he doesn't do solar) to help.  I'm sure such things are easy to understand, considering his job.  A bit more of a learning curve for me.

Will keep having a think, checking on prices and availability as I go.  I know I need to get the "two battery" lead as well.

From the research I did at the time, these batteries are supposed to be quite good.  Some complain that they're "slow" to charge the last 5%, but I read that this was all part of  preserving longevity, they deliberately put less power in when over 95% or there abouts... it basically trickle-charges that last 5% or so.

Had a bit of sun this afternoon, so battery at 96% and charging at just under 0.50kHw currently.  House usage next to nothing.