Just got marketting email from GivEnergy:-
For a limited time only, you can expand your system with an additional GivEnergy battery, with up to £1,000 off the RRP on selected models (2.6, 5.12 and 9.5 kWh).
But be quick – this exclusive saving is only available until the end of the January 2026
Email says ask for a quote - no prices in the email.
Anyone else got this?
alan_johnston Anyone else got this?
Yes. Looks like they want to shift the old stock before the launch of the Gen4 (which isn't compatible with the old batteries).
I think you are not the only one getting this...
Just got the mail. Just replied.
I will see what they quote me, as I had spoken to my installer in the summer who gave me a quote for another 9.5 then.
SteveCook how much did they quote you?
£3,100 installed. That was for the unit delivered to my door. I would move to into position and fix it to the wall.
The installer would then connect, test and commission
SteveCook just done the same haven’t heard back yet
Sorry the £3,100 was a quote from my installer 6 months ago. No reply from GivEnergy yet
but they don't sell direct only through wholesalers & they don't install kit either, so how does this actually work? - are they setting up their own "shop" now?
(I've not got the email, maybe I'm on the naughty list still)
The email says:
Reply to this email today and we’ll:
Check your existing setup and usage.
Confirm whether an additional battery is right for you.
Connect you with your original installer. If they’re unavailable, we’ll pair you with another participating installer.
hoggy
Probably (!!!), but here you go ( i know the link wont work)
Do two batteries play nicely these days?
I seem to remember a lot of issues with getting their socs more or less balanced otherwise one just sits there with charge but doesn't discharge cuz the primary is empty?
I don’t seem to have got the email, what’s the address it’s from please, I will email them directly and see what they say. I am doubtful it is worth it for me, but worth looking into it
Of course if they would give me a price for just one extra battery pack for a 9.5 then I’d be very interested …. 😉
geoffreycoan
Geoffrey.
It came from marketing@givenergy.co.uk
Is it possible to get two 9.5 batteries working on a single gen 1 Hy5.0.
I know i am limited on charge/discharge rate, but I really just want more storage
SteveCook thanks
yes multiple batteries on a single gen 1 inverter works fine, I had both my 5.2 and my 9.5 connected initially by installers to just one of my inverters by the installers until I worked out that this meant that all the solar power from the second inverter was being exported and was constantly driving the grid voltage up, tripping the first inverter offline.
When the 5.2 was moved to the other inverter, sanity was restored
But this is just an issue of my setup of having two inverters. Multiple batteries on a single inverter works fine, the inverter sees it as one giant battery. There are issues with the batteries not being totally balanced all the time (see other threads) and the inverter switching off charging or discharging when one is full/exhausted so you probably won’t always get the full capacity of both, but it still will make a difference
I’ll email them and see what they say
Cheers
From previous threads, I have seen a best case scenario of a 5 year payback. In some cases beyond the life of the battery itself. For a standard home with a single 9.5kwh battery, no car and no heat pump. is this offer going to tip the balance?
Henry3rd
Henry. Thanks.
My fag packet payback calculation when my installer quoted me £3,100 was about 5 years on current prices, but with potential (we shall see) saving of up to £1,000 and energy will go up, I may take a punt.
TX200 Do two batteries play nicely these days?
Imo no...
I have a 2.6 and 5.2 and they don't discharge fully and last night the 2.6 never reached 100% charge.
So in my experience they really are not great, acceptable but far from perfect.
Hmm I didn't get the email. I've already sunk money in to batteries - 3 x 2.6 (2 at install, 1 a year later) which don't play nicely at all with each other but I'd be tempted to see if it would save my sanity and hours of recalibration by moving to a single 9.5. Probably not worth the thousands it would cost though
Just as an example I have run out of power today and both batteries are at 15% but total system says 4%.
I am going have to check figures for last year but I think I used to run out of power in the evening not afternoon.
Not sure the 3020 firmware has helped at all.
Likewise a single large battery would have been better but space is an issue and getting the 5.2 moved is a struggle...
There are definitely issues with multiple batteries not balancing properly together and this is probably exacerbated with smaller batteries that have a smaller capacity and so when they stop charging then the impact of them not being full is more substantial.
Bang for your buck the bigger batteries are better value for money. If it’s worthwhile I would probably get another 9.5, put that on the inverter that currently has the 5.2 on it, and move the 5.2 to chain onto the existing 9.5.
But whether it’s worthwhile, I remain doubtful. The 2.6kWh charge rate (2.4kWh in practice) of my inverter is the limiting factor. I’m on Octopus Cosy for the winter so can only charge 3/4 of a 9.5 in a 3 hour cheap rate slot, so marginal benefit there. Export-wise it would give me a bit more flexibility and if flat export rates do drop and there’s a move to more time of day export rates Flux-like, having more capacity to do an export and to cover me through to the next cheaper charging period will be good. Have to crunch the numbers
In theory we would be a perfect candidate for this as with our Heat Pump we definitely want more storage.
Until I can get some support for our current system though ordering yet more kit from them seems tantamount to taking a bag of cash out of the bank and setting fire to it.
Before anyone rushes to spend money upgrading their system a read of recent TrustPilot reviews and the many many threads here and elsewhere of people struggling to get Support with faults would be wise.
SteveCook thanks for that. OK so it's likely sending leads to an installer (who may or may not still wish to continue fitting Givenergy kit depending on what experiences they've had) rather than some new install branch opening up.
Can't say I'd personally want to give any more of my money to the company that from the outside seems to care so little of its staff (the last week of Glassdoor has been particularly dire) in the same way that I understand why people don't want to support Mr Musk - but that's just me & everyone else is free to do as they please.
Another point worth mentioning is the export rates are likely to move downwards.
I'm a fairly low user, with a smallish bungalow, A2A heat pump for heating, an EV, 5.46kW solar, 5kW gen1 inverter and a 9.5kW battery, on IOGo. Most of my solar in the summer is exported anyway at 15p and the battery charged each night at 7p. Winter doesn't give enough sun to charge one battery let alone two, and with the gen 1 only charging at 2.4kW, it wouldn't charge both on the cheap rate in the time available.
If export prices fall, as it looks like they may in the next year or two, don't think I'd ever get my money back, and as others have said, with customer service the way it is, don't think I'll go there!
It would be a nice to have if I was given another 9.5, but the figures for me just don't stack up.
This could turn into a terrible offer.
Let's assume in February 2026, GE launch the Gen4 and immediately retire the old gen1, gen2, and gen3 systems. Worst case scenario, system installed in Feb 2021 with original 5yr warranty not extended. If additional new battery added, but inverter fails (out of warranty) in March 2026, the new battery is then useless because it is not compatible with anything.
Once the gen1, gen2, and gen3 are obsolete, they might start turning up on the second-user market at very much reduced prices.
Rubikcube Agree except to point out that the Gen 1 has already been declared obsolete by GivEnergy with only major security holes being patched and no new functional features.
And this happened within about 6 months of me having mine installed.
There has been beta versions of newer Gen 1 firmware in trial for ages. I’ve been running that beta firmware for 18 months now. The fact that this firmware has never reached the top of the testing pile and got formally released shows where it is in the priority list.
The second hand user market for GivEnergy inverters is limited because they need a registered installer to install and configure them. Presumably if they have been previously installed and commissioned you could use them in local-only mode with your app or GivTCP to control them as I can’t imagine you’d get many installers who would want to take on the responsibility of installing such kit.
Inverters are for sale at about £300-500 on ebay at the moment https://www.ebay.co.uk/sch/i.html?_nkw=givenergy+inverter&_sacat=0&_from=R40&rt=nc&LH_ItemCondition=3000
and are selling for about that price range as well https://www.ebay.co.uk/sch/i.html?_nkw=givenergy+inverter&_sacat=0&_from=R40&LH_ItemCondition=3000&rt=nc&LH_Sold=1&LH_Complete=1
e.g. a Gen 2 inverter and 9.5 battery sold (near me) for £1350 https://www.ebay.co.uk/itm/187756672236
geoffreycoan If we are quoting ebay listings, this one has moved from obsolete to "vintage and retro" 🙂
https://www.ebay.co.uk/itm/205889504132
Check the seller name.
geoffreycoan Presumably if they have been previously installed and commissioned you could use them in local-only mode with your app or GivTCP to control them as I can’t imagine you’d get many installers who would want to take on the responsibility of installing such kit.
Yep this is a big issue with second hand inverters as you can't just swap out your old one as you need to change that inverter with your serial number and that requires knowledge on how to do it. That is in the hands of GE.
I wouldn't buy an old inverter and use that serial number in the hope it will work.
Once my current kit dies and GE refuses to honour the warranty I will switch to an open source battery / inverter provider.
M_J Agreed, I suspect most people buying givenergy inverters off ebay are not aware of these restrictions.
My preference would be a more open battery/inverter platform as well, which puts me off Sigenergy which many people seem to like at the moment as its just a difference closed world ecosystem, although possibly less locked down.
Anyway, be interesting to see what kind of offers GivEnergy come back with. The economics are still doubtful for me, but always worth exploring if only to rule it out. There is I think diminishing returns with batteries, you need enough to see you through any time of use peak tariff (or at least a big chunk of it), and thereafter the savings become more marginal. But who knows, any financial calculation is based on assumptions about rates, and for sure they will change one way or another
In the morning, having charged my battery (5.2) on Cozy, I run out of battery in 90 minutes. A Cozy top up 1300-1600 will again run out of battery after 90 minutes though might just stretch to 3 hours it not cooking etc.
Clearly 2x5.2 batteries will not reach full power in 3 hours but my aim is to avoid the high tariff 41.39 as long as possible and top up at 27.6 when I need to.
Some interesting modelling of likely future rates: https://www.electricitybills.uk/2030
The trend is upwards, but probably a little below inflation.
Roy124 Sounds very expensive. EON offers 7.5p for six hours at night. I use that to charge the battery to full.
bRhFDKtjRMK9 it is a total system thing. Come the dawn, before the heat pump comes in, I have had 2 hours before midnight and 3 hours before 7 at less than 13p.
Much more importantly, from 1300-1600 I get another 3 hours at that low rate which allows for a full battery and a further hour of low rate.
If I doubled my battery capacity I would get tye equivalent of 75% charge which would give me more energy in the high rate period.
I could us Octopus EV tariff but would miss my afternoon boost for the heat pump.
bRhFDKtjRMK9 The advantage of Cosy is that you have lower rates three times a day, the low rate for us being 13.5p/kWh so about six pence more expensive than your overnight rate. With a Heat Pump you would likely require more battery storage than almost everyone here has to get you through the day. Not only can you give your Heat Pump a boost and/or top up the hot water during the cheap periods, you can recharge your batteries so you are actually averaging the low rate (or very nearly) rather than running out of battery during the afternoon and running at Standard Rate for the rest of the day.
Even with a relatively small Heat Pump and relatively modest household needs we would have needed well in excess 16kWh of battery storage in November. For the four winter months 500kWh of usage averaging 7.5p.vs 13.5p would cost an extra £30, so an extra £120 for those months. Multiplied over a 12 year warranty period that would give you £1440 which wouldn't cover the retail cost of a 5.12kWh battery, much less the installation.
For heating the heat loss is happening 24 hours a day thus the heating cannot be squeezed into a overnight slot of a few hours.
There are also many households without off road parking or with parking spots that aren't directly outside their house (think apartments for example). If there is no way to install a home vehicle charger then you aren't even eligible for the tariffs you are talking about, whether you own an electric vehicle or not.
Please do other users the courtesy of not immediately assuming they have not chosen the tariff that best meets their needs.
I need to try and find a fresh out the box inverter (or just do a factory reset of one of my spare ones) but I think I know what needs to be done to make it work from 'new' if the worst happens.
hoggy but I think I know what needs to be done to make it work from 'new' if the worst happens
sounds like a business opportunity to me 😃
My original installer quoted £3800 for an additional 9.5kw battery 18 months ago. I received the GivEnergy offer and requested for a quote. Their appointed installer has quoted, today, the discounted price of £3750 for the additional 9.5kw battery.
ddb2k good to hear, I'm out.
Looking at the original offer it says via your original installer (if still operating). I read this as a simple marketing exercise telling your installer of possible interest.
As there is an upto £1000/RRP hook your installer's quote should show abd discount.
If people don't take up the "offer" it's likely to get better as they will increase the "offer"
Installers are likely taking a bigger bung (slice of the discount) to take this on.
M_J done this way installers can set different prices. Interesting to compare offers.
In my case, as my box shifter went belly up 2 years ago it would be another installer who may or may not pick up the baton
I contacted my original installer and they mentioned that they were not aware of this offer and that it seems to be a direct to customer offer managed by GivEnergy through a list of appointed installers.
pwdst absolutely spot on on your analysis of Cosy. For the last two winters I was on Octopus Agile and it was a good option for winter 23/24, and progressively less good for 24/25 until I moved to Cosy in February 2025.
I’ve gone back to Cosy for this winter for all the reasons you say, with three top ups of the batteries a day I can achieve most of my consumption for the home and heat pump at the Cosy rate (14.05p for my region). I chose the Cosy fixed option for the lower rates, even though I may well change back to Agile for the summer next year, its still worth paying the £25 fee for the cheaper winter import prices.
My import for November:
The dark pink is the Cosy cheap rate which is the majority, the pale pink the Cosy day rate and the little bits of green the peak rates. I’m only incurring day rate and peak rate on the especially cold days when my batteries can’t see me through from one Cosy period to another.
I did run the numbers for Octopus Go and it would be about £120 more expensive for the winter. Cheap overnight but I’d run out of that cheap electricity probably by early afternoon.
ddb2k as I said my original provided went Tango Uniform. I think i still have the actual installer"s but my installation was his first for Givenergy so no idea.
Aa for some installers haven't seen the offer, has it been confind to Gen 1 owners with one battery?
Roy124 , has it been confind to Gen 1 owners with one battery?
I have a Gen 3 with 1 battery and I got the offer, so presumably not... 🙂
Roy124
I have a Gen 1 Hy5.0 and a 9.5. I replied to the mailshot (as I would like another 9.5).
I spoke to my installer and he was not aware of this GivEnergy campaign.
He had already quoted me in the summer for another 9.5 and he is going to check current prices, as well as tell me what GivEnergy say to him (if they do get around to contacting him!!)
SteveCook my installer knew nothing. They asked me to forward the GE email so I did. As many have said almost certainly uneconomic but asking costs nothing.
Didn’t get the mail shot, not sure if I opted out at some point or it’s because I have two batteries already. My original install went under, but I’ve emails the company that Givenergy say has taken over the ‘ownership’ of my account… not sure the economics will stack up, but worth getting the info to decide.
geoffreycoan I did run the numbers for Octopus Go and it would be about £120 more expensive for the winter. Cheap overnight but I’d run out of that cheap electricity probably by early afternoon.
I'm still on IOG, and do often run out early afternoon. But have had a few bonus evening slots which help a little. (I must write some scripts to pull the different sources together.)
Nov. was 767kWh for £82.79, giving an av. unit price of just under 11p. (Less £16 for export.) Fingers crossed for Dec/Jan - last year they got close to Cosy price.
I think I need about 2/3 of units to be off-peak to be cheaper than cosy: .67x7 + .33x29 = 14.26
pwdst Please do other users the courtesy of not immediately assuming they have not chosen the tariff that best meets their needs.
Please point out where I did that, I can't seem to locate it in my brief, 20-word long post above.
bRhFDKtjRMK9 I don't know how it could be read any other way than implying it was a poor tariff choice and your tariff is/would be much better. I am pleased this wasn't your intention.
Has anyone actually had a reply back from Givenergy ??
I replied, and have had zip. My installer said they didn't know anything.
DLadd nothing. Installer also didn’t know
SimonClarke
No reply from GivEnergy, installer knew nothing about it
No reply from GE here either.
Maybe an overwhelming response which then needs individual response
I think the point people are forgetting about the payback is truly calculating the useable capacity of the battery. Of a 9.5 (I'm going to assume an average 10% degradation which I'm almost already seeing after 1000 cycles but I'll give benefit of the doubt), you're left with 8.55kWh after deg, then you lose 4% of that which you cannot use ->8.2kWh left, then about 80% efficiency on the discharge ->6.5kWh useable capacity. Assuming it takes about 9.5kWh to charge a degraded 9.5, the savings are not as big as people think. These are real world figures I'm currently seeing.
Payback very much looking depends on where the battery power is consumed. Assume 8kW returned to grid at 15p it might be worth £1.20/hr. If it replaces grid import at 42p the payback is much more.
But if its charge comes from low tariff, say 13p, the sum is different.
Are we also assuming 5% pa loss of income?
Personally, having written off around £10k and £500pa income taxed, (£400) the whole exercise is probably zero sum.
OTOH we rather enjoy a £1000 pa variable saving from income.
As per Tim&Kat I could make the case for a second hand 9.5 at a grand. Whether my installer would be up for it is another matter
If this marketing exercise is to sell off the last of this type of batteries before moving to the new style, which I understand is not backwards compatible, could this then open the door for allowing second hand batteries to be added to an existing setup more easily? If the manufacturer aren’t making them anymore but have sold the existing kit as expandable it would seem to make sense, they don’t have to warranty the second hand batteries, just let people add them.
So my installer has now reached out and asked what I'm after and for photos of the install area. I've gone back to them with it.
I'm in a similar boat as so many here - I'm on a gen 1 inverter with it's limited charge rate. I've struggled to make the sums work at the prices I've seen online and that's before installation costs.
If it's an amazing offer - then it's one to consider - but it'll have to be amazing.
My Installer has also reached out and quoted me £2375 for a 5.12Kw and £3700 for a 9.2Kw I did confirm it was a Gen 3. The quote to me is what you would pay without any discount.
Rodmac76
Can you please explain a bit more. Is that £2375 to add a 5,12 kWH battery to you existing setup?
Does not seem a particular bargain price
I thought the plan was to clear out old Gen 1 and Gen 2 batteries?
SteveCook Yes to my existing Gen 2 inverter and 8.2KW battery. They are going to call me next week to discuss further but I also cannot see a saving, it just looks like a standard add on. Be interesting to see what others are quoted.
Rodmac76
See my post #6. I spoke to my installer about 6 months ago and he already quoted me £3,100 to add a 9kWH battery to my existing system.
I will wait to see what the GivEnergy offer is - though the wait could be a while?
They said up to £1000 off didn't they? Key is up to!
There might be certain types of batteries and/or certain sizes of batteries that they have lots of and I'd guess the best discounts would be on the larger size batteries (as they cost more on the first place) and newer batteries (as presumably older ones would need a good discount to shift, people want newer ones???)
Just a thought they might have not consulted their retail suppliers like midsummer, depending on the sales arrangements if the supplier holds stock already paid for then they would be mightly pissed off if they were undercut by this announcement.
Might explain the lack of any further news or progress on this.
Just checked they are showing Gen 1 2.6 batteries for £673
I sense a huge "own goal" somewhere.
M_J Midsummer don't actually have any at that price though, if you click buy then the product isn't available. Presumably this was a clearance price and has worked.
pwdst
So I wonder if I will actually get an offer of a Gen1 or Gen2 9.5 battery if there are not enough to go round.
If not, that kills my upgrade path, as I understand I cannot have a Gen3 9.5 battery added on
Got offered a gen 3 9.2 or 5.1.
3k for the 9.2 and 2.2 for the 5.1. Quote shows it as a 20% and 19% discount respectively.
I doubt it'll add up but I'll do some work on it.
MikeyHaz
Did your offer come via your installer - as the mailshot suggested it would?
I was quoted £1,751.91 supply and fit for a 5.2kWh battery in January 2024 so I am not that impressed.
pwdst The 5.2 was the Gen 1 battery and only 80% depth of discharge, so 4.0 or 4.2kWh capacity in reality.
The new Gen 3 5.1 (actually 5.12kWh) is 100% DoD so you are getting 25% more for your money.
But not a fantastic deal I agree
I am aware that it isn't exactly like for like but there is also almost two years of rapidly falling battery prices to account for.
Are there any issues running 2 batteries, either the same or different capacities, from a Gen2 inverter? Our usage has changed so much since fitting the original system so I'll have to do some maths. Prices don't seem that good though.
Lincs_Will have a look at other threads. There are reports that with multi battery chains on the same inverter, that all batteries stop charging and discharging when one reaches full or empty. With dissimilar battery sizes this could be exacerbated.
@MikeyHaz Looking on its technologies.shop https://www.itstechnologies.shop/collections/givenergy-battery-storage a Gen 3 5.12 is £1375+VAT, a 9.5 is £2,000+VAT. Should be VAT free from the installer. Looks like in the quotes above they are charging about £1k for the install?
Yes
They haven't broken out the install. Just a single line on the quote.
My Gen1 yesterday the master battery a 5.2 stopped at 20% because the 2.6 slave had reached 9%.
This issue has got worse since I had the inverter replaced.
If I could go back in time I wouldn't have bothered buying the second battery.
YMMV
So here's my logic on the pricing.
I'm on flux - I do plan to get an EV next year that could mean moving to Go - but I'll have to run the calculations using Flux. I have a Gen 1 5KW, 6KW solar and a single gen 1 8.2Kwh battery.
My gen 1 has a max charge rate of 2600w - so in my 3 hour overnight 'off peak' charge slot - I can get about 8KWh into the battery system. It's the same for my peak period in the afternoon for discharging. So I cannot charge more into a 2nd battery overnight.
My house consumes an average of about 19KWh.
If we take import and export out of the equation for now - for 60% of the year I don't generate enough solar to cover all usage (<20KWH). On those days an additional battery isn't going to make a significant difference. You can argue that on those days that 20KWH could fill both batteries and reduce import at peak.
However, of the spend I've done in the last year - only 10% has been in the 'peak' period - leaving about £50 available to 'optimise' out. The majority of that is going to be import above the 2.6 discharge rate anyway. The day rate optimisation should already be occurring thanks to Predbat so I have to assume my day rate is already as good as it gets.
To be able to fill both batteries and cover house usage - I'd need roughly 36KWh of solar - that has occurred on just 4% of days since I've had the solar installed.
So just on house usage - this seems to be a no-go.
Take it a different way - what if I say 'ok - the existing battery/solar works for the house - let's assume this is for arbitrage on import/export'
If I assume that this extra battery could be filled completely at flux import rates overnight, held and then exported at the peak - I could make an extra 94p a day (29-16.43 * 7.5Kwh) so - in theory - an extra £343 a year in a perfect world.
Reality will be very different - that doesn't allow for house consumption and the peak export period does occur during peak house usage (cooking). So assume that I can only export 5KWh in that peak period instead and I'm at £229 in a year IF it's perfect import and perfect export to fill that battery.
So even in that world - I'm on a 13 year payback.
There's a bunch of what ifs that can be run - but if the perfect numbers don't make sense - I can't see how I can make the imperfect 'yes but' type numbers make sense.
And on top of that - I run the risk of the 'multiple battery' problems we see elsewhere. Make it £1000 for the 9.2 and I might get interested. Make it 3k to move me to a gen 3 inverter AND the 2nd battery and I might get interested.
Agree with everything you say, I’ve done similar calculations myself and come up with paybacks of between 5 and 22 years depending on the assumptions made. For us with slower inverters, extra battery storage doesn’t make sense as you just can’t use it. I could charge more solar into batteries during a summer’s day, but the storage I have now is sufficient to run the house overnight during the summer, so its more effective to export extra solar once the batteries are full.
MikeyHaz My gen 1 has a max charge rate of 2600w
Sorry to make the figures even more depressing, but in practice we get about 2400W charge rate.
The only practical improvement is to add a second inverter alongside extra battery storage. You’ll have potential cross charging to deal with but that isn’t insurmountable. I have two Gen 1 hybrid’s each with their own battery (a 9.5 and a 5.2) and they do play well together, sharing the load. I get a combined charge of 4.8kWh and discharge at about 5.2kWh.
A second inverter is about another £800.
Just arrived
geoffreycoan Sorry to make the figures even more depressing, but in practice we get about 2400W charge rate.
I have noticed that on my gen1 hy3.6 with 8.2 battery. It only charges at 2400 despite being set at 2600.
alan_johnston yes that’s the point I was making. The inverter has a theoretical charge and discharge limit of 2600W but in practice only achieves 2400W when charging. Discharging seems to vary by battery type, I get 2400W from my 5.2 battery and 2900W from my 9.5.
And, returning to the subject, I’ve not received an email from givenergy marketing following up on the original mail shot (which I didn’t receive either)
I got the mailshot of the 'the installer will be in touch' email too. I've responded with the quotes I got and pointing out the online prices you can buy it at pre-discount and asking if they really intended for this to be an 'offer'.
Don't expect a response - but we'll see.
After sending my Installer the mailshot they have came back with a 9.5Kw Battery for £3355 so a saving off £345 from there initial £3700.
A Fogstar 16kWh battery and an AC Coupled inverter would seem to be a heck of a lot more bangs per buck to me......
Probably a very similar price to just a 9kWh battery, plus you wouldn't be funding a company with a terrible attitude to its customers and installers....
Asking for a friend....
Zakalwe Looking at ITS Technologies fully fitted prices:
5kW AC Solis + 10.24kWh GSL battery £4140 https://www.itstechnologies.shop/collections/sunsynk-installed-packages/products/fully-installed-package-solis-with-powerwall?variant=55029110997373
ITS will be taking a cut as will the installer, so could probably get cheaper by going direct to an installer. I couldn't find prices for Fogstar on ITS or Midsummer solar
geoffreycoan couldn't find prices for Fogstar
Fogstar is the "premium" of the cheap brands. They have a good reputation, but some supply chain issues at present. 10kWh for £1500.
How much mix and match is possible? Can different batteries be paired and connected with a third inverter?
Roy124 How much mix and match is possible?
If you need to ask, then it's probably not for you. Lot's of information on youtube. Check this one out for a fairly good sunsynk/fogstar combo.
https://www.youtube.com/watch?v=p10kaQ185G0
Always stay within your technical competency. Electrical equipment and batteries are potentially dangerous. Not worth burning your home down (or worse) trying to save a bit of money.
Roy124 Can different batteries be paired and connected with a third inverter?
If you are asking about GivEnergy inverters and batteries, they are proprietary and can't be connected to other company's products. I believe the inverter can "accept" lead acid battery connections but that's probably not much use
Rubikcube if you don't ask as question you will never learn.
Interesting, thanks.
Having seen the prices coming back in response to this 'offer' I do think Givenergy are taking the piss for flogging off old stock as I've been receiving Fogstar's emails for ages. I regret buying into such a closed system. I was suckered in with Giv's attitude to smart features I'd assumed would maximise ROI as they developed. Since install I've discovered Home Assistant and the brilliant Predbat. If I was to do it again I'd buy the most open system possible and deal with it myself. I now wonder if I could use Prebat's inverter balancing feature to balance a 2nd (Solis?) inverter and Fogstar battery. There's spare space for extra MCB/RCBO in the consumer unit installed to add in the Givenergy system so hopefully install costs wouldn't be ruinous. Will have to do some reading.
The advantage of Cosy is that you have lower rates three times a day, the low rate for us being 13.5p/kWh so about six pence more expensive than your overnight rate. With a Heat Pump you would likely require more battery storage than almost everyone here has to get you through the day. Not only can you give your Heat Pump a boost and/or top up the hot water during the cheap periods, you can recharge your batteries so you are actually averaging the low rate (or very nearly) rather than running out of battery during the afternoon and running at Standard Rate for the rest of the day.
Even with a relatively small Heat Pump and relatively modest household needs we would have needed well in excess 16kWh of battery storage in November. For the four winter months 500kWh of usage averaging 7.5p.vs 13.5p would cost an extra £30, so an extra £120 for those months. Multiplied over a 12 year warranty period that would give you £1440 which wouldn't cover the retail cost of a 5.12kWh battery, much less the installation.
For heating the heat loss is happening 24 hours a day thus the heating cannot be squeezed into a overnight slot of a few hours.
There are also many households without off road parking or with parking spots that aren't directly outside their house (think apartments for example). If there is no way to install a home vehicle charger then you aren't even eligible for the tariffs you are talking about, whether you own an electric vehicle or not.
Please do other users the courtesy of not immediately assuming they have not chosen the tariff that best meets their needs.
Totally agree, Folks
Even driving a 16kW ASHP 24/7, having 2 X 3kW inverters with 16 kWh of battery storage, Cosy is a really good option, with its three slots. As as already been mooted, despite there being some cheaper one-slot tariffs out there, the three 14p slots offered by Cosy means that we can get the ESS fully charged during each slot, and manage to run the whole house (cooking and all!) off it during the expensive slots - meaning that at least for the winter months, we're averaging 14p for all of our energy - including running an EV (we never charge publically - just off the domestic supply).
... in the winter, I ignore any solar contribution in my calculations, but actually, on days like today we're running everything off the roof - with a little spare for EV charging, too.
As @pwdst mooted, it's horses for courses when it comes to tariffs, and we all have such differing needs / means / amounts of space etc meaning that there's no 'one-size-fits-all' and we all need to find the solution that best matches our own installation.
I'm just glad that we all have such a selection from which to choose.
I also think that, like 'em or love 'em, Octopus have done so much to single-handedly drag our aged industry suppliers into the 21st century - many of whom are now offering more choices, despite still being in the dark ages...
Sykes indeed I have tweaked my system to heat hot water and charge the batteries on cheap rates towards the end of the cheap rate rather than as soon at it starts.
The battery is full just before the high rates.
Roy124
Hi Roy
There may be some differences between our systems, but it shouldn't matter when (during the window) you charge - even at the beginning, as long as you programme the charge period to end at the end of the cheap window (e.g. 04:00 - 07:00).
Thus, even if your battery(ies) is/are full halfway through the cheap window, they won't begin to discharge until the cheap slot ends.
We certainly don't want to be using battery power during the cheap period, as 'round trip' losses through the inverter effectively make our battery discharge power a bit more expensive that the unit charge for charging it.
Do check - to make sure my earlier statement is correct for your set-up, though; my kit's relatively old now - having been installed for three years, or so.
Did anyone ever get any offers from this? Or offers worth following up on? I never heard anything more from Givenergy, my installed or any other installers after getting the initial emails!
Nothing ever received by me, other than initial mailshot.
Not a sausage
Zip received here
Best quote they could give me was £3450 for additional 9.5 Gen 3. I was considering looking into a retro fit Eco flow to run the base load, but maybe wait until legislation is signed off to connect directly to the grid using a power socket.
I've had nothing.
I got a response, but never had a follow up. I even submitted a 2nd query.
I'm very much looking at the Fogstar batteries now.
Hook there is part of me wondering about the payback on Fogstar batteries and AC inverter.
I'd need to ensure they don't cross charge with the givenergy.
Probably a pipe dream, but am wondering about it
I have emailed GivEnergy asking where my promised quote is. So far zero reply
SteveCook will you paint your house and watch the paint dry?
Roy124
No, I am building a wall and using my head to align the bricks
geoffreycoan This has been living rent free in my head for days. 😂
After reading this thread, I tried my original installer. No response so far, about a week.
Anyway, I have already started looking into AC coupled additional energy storage, and I have the same questions as @geoffreycoan: How will the GivE system and the new ESS cope together on the same connection.
If only the universal BMS supported givenergy then you could just bolt anything in: https://github.com/ai-republic/bms-to-inverter
Hook there’s some interesting man maths you can do with that quote
£5495 for 32kWh with 6kW Solis inverter
£4500 for 16kWh
so 16kWh “costs” £995
an inverter is about another grand or a bit less
so that works backwards to about £2,500 for the install labour, quote, common components such as cabling, glands, brackets, DNO approval, base price of the battery cabinet (without cells), etc. Which seems a lot?
Danger of man maths
I’ll have to do some man maths on the benefits of a 32kWh system. An extra inverter being able to charge in parallel to my GivEnergy inverters in the Cosy cheap periods (so not constrained by my Gen 1 inverter throughput) and give me more Cosy 14p vs 28p day rate electricity arbitrage. Then the extra income from overnight cheap importing and evening peak rate exporting in the summer.
rio911 How will the GivE system and the new ESS cope together on the same connection.
There’s two key things to enable them to coexist:
1 is easy, 2 is harder because you want all the inverters to respond to house load. I wrote a long post outlining different ways of achieving this that I was aware of, so not repeating that but simplest I suggest are:
a. Set one inverter to constant discharge at your base load rate, the other inverters then pick up the variable peaks and trough load
b. Set all inverters to Eco/demand mode but disable charging. So inverters will respond to house load but can’t cross charge between themselves.
Option a will get a bit of cross charging, but not lots. Option b stops cross charging entirely but does mean that all solar generation over and above house load is exported, but if you are on a cheap (eg EV) overnight tariff then you probably want that anyway.
In short, it is doable with a bit of care and some limitations
geoffreycoan The other part of my thinking is the Solis inverters have a smart load feature.
I'm wondering if the Givenergy hybrid's can be run in AC mode via the AUX port.
Hook My hybrid Gen 1's run in AC mode as well as hybrid mode. This was an additional benefit I wasn't expecting when I upgraded to the 'fast response' firmware.
As I have two Gen 1's and an older FIT inverter (without any batteries) the AC mode means that the GivEnergy inverters will soak up any excess AC that would otherwise be exported if their panels are not generating the max 2.6kW battery charge rate.
I believe all the later inverters have this feature.
geoffreycoan Those are very good strategies for the two systems to co-exist. There are some complexities but as you say: doable. Then something else caught my eye: DNO approval. If I already have a G99 approval, do I need a separate one for the additional ESS?
rio911 In theory yes as you're changing the amount and type of storage. In practice I think there's a lot of cowboys out there who simply don't bother. Anyone who's MCS certified will put in new documentation to the DNO.
rio911 yes as Vestas says, your DNO approval is for the total amount you can export so if you add inverters you will need to apply for a new G99/G100 approval (I have a G100 approval for mine).
Your DNO may grant you the full additional inverter capacity or a lower limit, if a lower limit then all of your inverters will need to be configured with this limit.
geoffreycoan You're actually supposed to notify them about any BESS (battery storage) as well. All generation/storage is notifiable.
The thing to bear in mind for people with a G99/100 is that any changes to existing installs may result in a reduction in existing export limits as the local area may have a lot more PV than when you first applied. This doesn't appear to be happening yet but as more people get PV it is more or less inevitable.
Vestas yes you’re correct, when I had an additional battery installed after my initial G100 approval, my installer had to get a further DNO approval for the BESS
Weirdly the second DNO approval said:
Agreed export capacity per phase: 0.00kW
G100 export limiting on premises: No
So quite what that means I don’t know. When I submitted my DNO approval to Octopus for my export MPAN I submitted my first approval which was for 10kW (my inverter limit) and it went through OK.
But the point about DNO export limits being reduced is potentially a risk yes. I certainly see grid voltages increase on sunny days because of other solar in our village
Just had an email from Givenergy:
Dear Customer,
We understand that some people are still awaiting a reply regarding the low voltage battery discount for existing customers. Please be assured that this promotion is not ending any time soon and you will not miss out.
If you haven’t received an email yet, this is by design. We are deliberately staggering the outreach to avoid overloading the installers due to the incredibly positive response. You will hear something soon.
Installers have been informed of how they can facilitate this promotion, so please wait for a response from us directing you to your nearest installer.
Sincere apologies for any confusion or inconvenience caused.
Thank you for your patience,
GivEnergy Team
geoffreycoan Weirdly the second DNO approval said:
Agreed export capacity per phase: 0.00kW
G100 export limiting on premises: NoSo quite what that means I don’t know.
It means your generation capacity (and hence export limits) remained unchanged. Adding a battery doesn't affect your generation capacity whereas adding an inverter/AIO does.
Vestas thanks, I figured it was something like that, but its not exactly transparent to the end consumer
Just go the quote for my installer for a 2nd 9.5kW battery installed:A bit more than I'd hoped considering the running discounts
So in the same ballpark as mine (about £100 cheaper). Need a bit more data - but it feels like that's the price people are going to get.
I did post on faceache as well and had some responses this morning/last night
I went back to my installer this morning with these and they've knocked another £100 off, so £2780 now.
£2400-£2800 is a good reduction on the typical £4k it was a couple of years ago, but still a challenge to make it add up financially.
Interesting to hear about some installers not passing on the £500 discount. Inevitable I guess
Yes, some greedy installers...
Anywhere from 80p to £2.10 on single cycle per day arbitrage for me so anywhere from 3.6 to 9.5 yrs pay back purely on battery cost but probably realistically 5-6 yrs.
It adds 1.5 yrs to our combined solar and battery payback time which currently runs at about £1,950 PA, but should push those number up towards £2,300 PA easily.
I haven't received this email, so how can I get an installer contact or even a quote? Direct from givenergy or the installer?
rio911 Yeah I have the same question, my guess is I've not been mailshot because my installer went out of business (first4solar) just after everything was thankfully installed and commissioned.
I never got the email either, and my installer is still in business. I emailed givenergy about the offer to get a quote, never heard anything more
I got a second email recently saying they were still working on it. Not heard anything from my installer except them asking me what it is about…
Got the original mailshot at start of December. On 15th Jan, I emailed GivEnergy to ask where my quote was.
Just received an email asking me to fill in the mailshot form again, and that "someone will be in touch"
SteveCook I have never received a mail shot from GE either.
Looks very hit and miss.
Rob
Rbor me neither. I did email givenergy to ask to express my interest, but nothing back
After me chasing GivEnrgy for a quote, I got a call last night about 7pm.
Said he was from GivEnergy following up. Asked what kit I had and what upgrade I wanted to do.
I thought that was odd as someone from GivEnergy would have the details from my response to the mailshot and/or my portal.
When I asked this, he said he was from an installer.
When I said that I had ticked the box "contact my original installer" and that was not him. He said "ah computer problems", and that GivEnergy had asked him to contact me!
When I asked for a price he quoted me £3,050 for a 9.5 battery installed and commissioned, which is more than my original installer quoted me 18 months ago, when I had discussed this with him.
I said that did not sound much of an offer. He told me that the installation was VAT free, but I had to pay VAT on the battery.
I said goodbye
I will talk to my original installer who I trust for anything I want done, though GivEnergy have not contacted him
SteveCook I wonder if you'll now get spam from "Powerdog"....
I just had a e mail drop from my installer for a very limited time to offer a special offer on a GivEnergy 9.5kwh Battery that is ideally suited to extend an existing system. We are able to supply & fit a 9.5kwh Gen 3 battery for £2200 inc 0% VAT. (offering a saving of £900).
The offer is still available maybe clearing stock of THE LV system.
No real use to me as I have a dual AC‑coupled inverter system with four 9.5kwh batteries with EMS and EPS. I would need to add another AC‑coupled inverter to allow me to fully to use within the winter months for my heat pump.
Simon-D what part of the world is your installer?
Gloucestershire, The offer maybe only available to his customers first.
Ah well never mind. Doubt he would travel to east Norfolk anyway!
Yes East Norfolk maybe too far out of his area.
That's a good price, my Norfolk installer wants £2800
wrighar I can recommend CRC Electrical based in Kings Lynn for Norfolk installs. But I know their default suppliers can not get hold of giv kit just now. But they did install one I got off ebay a while back. Good team, I have had them add to my system for the last 4 ish years.