8 Key Factors When Choosing the IDEAL Home Battery

[@adon8672]

I bet this man is a professor somewhere. Thanks for the wonderful videos.

[@GaryDoesSolar]

I’m not a professor, but I do a lot of presentations as part of my day job in the mobile industry 👍🏻 thanks for the kind words

[@markrichardson8299]

Regarding the clipping - it depends how much excess solar you have, I also have a Giv system, 5kW gen2 and 9.5kWh battery. That's fed by 10kWp of panels (E/W split). It often exceeds 5kW. I use automations on Home Assistant to throttle the battery charge rate based on current generation to leave room in the battery through the day to allow that excess to charge the battery instead of being clipped. On a sunny day, that's worth maybe 6 - 7kWh for me. Really need GivEnergy to do a bigger inverter!

[@GaryDoesSolar]

Good point, Mark - and East/West configuration will certainly flatten that bell curve making the area above the inverter limit slightly bigger. And it sounds like you're making really good use of the automations in adjusting the charging rates - very clever :-)

[@apiscator444]

I noticed Fox do a 10.5 kW converter with 4 mppt string input. More expensive but would appear to support larger house installations with multi roof orientations.

[@Will_C_188]

My day is always better when Gary posts a new video!

[@GaryDoesSolar]

And your comment has just made my day! :-) :-) :-)

[@binaryboyo9674]

Even if it's Rainy & Cloudy too! 😉😂👍

[@ericjoe4573]

Thinking of adding a battery without solar. We had a seven hour power outage yesterday. Out came the Honda gas generator. It seemed heavier than I remember it. Had to get some gas. A real pain in the shoulder. Could only power the refrigerator. Gary's video explained things that I was not even aware of. Great job Gary. You must have a degree in Electrical Engineering. Everyone thinking of solar or batteries should watch these videos. Thank you very much Gary.

[@GaryDoesSolar]

Thanks Eric, and yes - Electrical and Electronic Engineering :-) I always wanted to do software engineering and that was the closest course there was at time - it was a great course!

[@MaritimeUnprepared]

I moved into the forest of Atlantic Canada off grid 2 months ago and it's been "interesting" lol. My solar system is in it's infancy but I have three 100ah lifepo4 batteries and a 3000w inverter. I can charge the batteries in around four hours and they'll keep my fridge running for approximately 5 days. Every home should have a lifepo4 bank imho

[@Christopher-j6k3f]

It would be great to see a video about inverters in parallel multiplying capacity.

[@GaryDoesSolar]

Thanks for the suggestion - I'll add to my list of future videos - I have to warn you though, it's getting to be a LONG list! :-)

[@Anonymouseys]

I'm quite new to all this and I'm trying to learn it all at once. I just wanted to say that this channel is superb. It is, by far, the best in this space and I'm learning more every video. Thanks, Gary, this is excellent.

[@GaryDoesSolar]

It's this kind of feedback that keeps me going, when I'm finding it hard to make time to work on the videos - thank you! :-)

[@MrKlawUK]

This is perhaps the best explanation of DC and AC coupled I’ve seen. Goes into practical use cases and realities - great point about the ‘combined’ power often not being a big benefit - if you have a strong enough solar day to go past your DC inverter limit, its likely you’ll have a full battery quite quickly like your example. For AC coupled, yes less efficient, but if you’re playing with losses from solar, its not a direct cost to you, just a trimming of your overall generation and no direct cost to you (tiny amount loss of export over the year maybe)

[@GaryDoesSolar]

Thanks for the great feedback, and I agree with your comments!

[@xxwookey]

This is indeed a very clear explanation of DC vs AC coupled batteries, but it's worth bearing in mind that you can also have DC or AC coupled solar panels with a similar set of tradeoffs. i.e you can have an AC-coupled battery with DC-coupled solar panels, and he didn't cover that option. Also he's very optimistic about the conversion losses - they can be more like 10% than 3%, and are quite heavily dependent on the power lever the conversion is happening at. So you might find you are getting 25% losses on PV power going through a battery back to AC is you are not careful.

[@tomking5855]

Great explanation of AC and DC coupled batteries.

[@GaryDoesSolar]

Thanks Tom 😀👍🏻

[@johnadams1976]

Nice and clear presentation style.

[@GaryDoesSolar]

Thanks John - really great to get this feedback. This particular video was very difficult to put together, but it seems to be going down well :-)

[@binmanblog]

Hi Gary, Great video! I'm just starting down the Solar path and your channel has been by far the best for someone like me. Thank You.

[@GaryDoesSolar]

That's so great to hear, thanks for letting me know!

[@derrickkerley5707]

Great job. Thank you!

[@GaryDoesSolar]

Cheers 😀👍🏻

[@redshift3]

Great video. On the DC coupled battery you said (and so do many others) that there is no conversion required to send the power from the PV array to the battery. It is correct that there is no AC conversion. However, there is a DC to DC conversion so that the DC voltage at the battery and the DC voltage at the PV array are different and controlled to meet the needs of the battery and the PV array. DC/DC conversion is more efficient than DC/AC conversion but it is not 100% efficient and so there are still some (lesser) DC/DC losses when charging a DC coupled battery.

[@GaryDoesSolar]

I hadn't considered this aspect - great point! Thanks for sharing.

[@xxwookey]

This conversion is typically 98 to 99% efficient (as least with Victron MPPT kit which I have numbers to hand for). But the DC->AC conversion (and AC->DC conversion can be only 90%, and is very dependent on power level). It can be 97% (and that's what your inverter will advertise) but that will only be under one particular circumstance which may not apply much of the time - all others will be worse.

[@lexxel01]

you are one of the best tutorial presenters

[@GaryDoesSolar]

I'm very humbled to hear that - thank you! :-)

[@northernouthouse]

Excellent video. It should be a must watch for all solar panel owners.

[@GaryDoesSolar]

Thank you - such great feedback! ❤️

[@johnyogiburr2881]

Excellent video as usual

[@GaryDoesSolar]

Cheers John :-)

[@glockieme]

Thanks Gary. Lots of very useful information, especially the cost!

[@GaryDoesSolar]

Cheers - and I'm hoping to cover battery ROI in a future video as well :-)

[@Pressure_23]

Excellent video. Watched the series. I have 5.6kw PV plus an ASHP, self consumption is 95%+, but considering a battery to time shift import on Octopus Agile. Figuring out how big it needs to be based on consumption. Biggest issue is where to put one, batteries are big and the plant room is already full of ASHP and heat recovery / ventilation kit! If only I had a garage….

[@GaryDoesSolar]

Yeah, space is an issue when getting into the renewables space! Hope you're able to find a solution :-)

[@nicflanagan6662]

Just brilliant. Enormously informative. Thanks very much. Just forwarded to a number of neighbours who are look

[@GaryDoesSolar]

That’s really kind of you, Nic - thank you! 🙏

[@nicflanagan6662]

@GaryDoesSolar sorry for some reason my msg froze. Hopefully you got the jist. I think I mentioned before, i used to do sales training courses around the world. I now shudder looking at your professional content 🤦. Flip charts or OHP.... imagine if you can .... picture if you will 🤣🤣🤣🤣

[@GaryDoesSolar]

I can picture this very well, Nic - in the late 1980s I was also travelling around the world presenting using OHP slides! 😮😊

[@whistling_jim]

Brilliant as ever Gary, thanks. I’m looking forward to my GivEnergy AIO installation plus solar PV in September.

[@GaryDoesSolar]

Thanks David, and I hope your installation goes well. I'm hearing great things about AIO :-)

[@paulpopplestone7837]

Yet another clear & concise video, great work! With Sodium and other technologies on the horizon, hopefully you’ll do an update to keep the info fresh & up to date!

[@GaryDoesSolar]

Thanks Paul - I'll keep the videos coming! And I just love how technology just keeps on getting better - I'll take a look at how sodium batteries are coming along - it's been a few months since I last checked...

[@jeremyallard7015]

Hi Gary, you appear to be one of the most (switched on) KZbinrs. I always believe that bigger is better as I live in the tropics and am still working on my Solar design to accommodate A/C with Soft Starters to avoid Inrush Spikes, I am considering a 30 kWh Battery at 48V with 24 kWh inverters, where possible I want to have a DOD of 70% and a large solar array in S and P. I am probably going to use your software to model days of autonomy, as well as other factors. Thanks for such good presentation.

[@GaryDoesSolar]

Cheers Jeremy - that's high praise indeed! :-) And I hope you like using the utility!

[@noimnotarobotcanubeleiveit7024]

up your voltage! there is so much loss in low voltage high current systems, and copper wiring and busbars have to be huge thick and expensive

[@MinotaurUK]

On the AC/DC coupled battery issue, there are a couple of factors that have influenced my decision: 1. Ability to run in a completely offline mode, that is to say, provide whole-building power from either solar, battery, or a combination thereof if the grid is down. From what I've seen, most AC coupled batteries require grid sync to function, and will power down (for very good safety reasons) if the grid is offline. Perhaps a trivial issue if you rarely have power cuts, but for those of us in rural areas, more of a consideration. 2. The cost difference between 3.6kW, 5.5kW and 8kW hybrid inverters seems to be relatively trivial (

[@GaryDoesSolar]

Great insight - thanks for sharing!

[@michaeldepodesta001]

Gary, Thank you for another excellently produced video - they must take you ages to research! But you missed out something: Battery Self-Consumption: the power used by the Battery Management System to run the environmental controls, web servers and monitoring software. It's really hard to work this out but I think it amounts to many tens of watts - possibly more than 50 W continuously i.e. more than 1 kWh/day of your charge is 'stolen'. It normally shows up as 'household consumption' in the App that goes with the battery but does NOT show up on a smart meter! It's an important and rarely discussed issue: I'll be writing about it soon. Best wishes Michael

[@GaryDoesSolar]

Hi Michael, cheers for the kind words - yeah, this particular video took me ages to put together. I didn't expect it to be so long, and I didn't get a chance to cover ROI yet either! Future video then... Great point about the power drawn by the system itself - even at 50W it quickly adds up over 24 hours - crikey!

[@varnect203]

G DoesSolar let’s goooooooo!

[@GaryDoesSolar]

Cheers! :-)

[@stevebella4221]

Thank You Sir for your Informative videos.

[@GaryDoesSolar]

You're very welcome, Steve - I'll keep them coming... :-)

[@cyclemoto8744]

Thank you for sharing. Cheers from OZ

[@GaryDoesSolar]

You're most welcome! And I'm very jealous of all that sun you get there! :-)

[@chris-williams]

Really helpful & informative video and appreciate the time taken to make it. With the release of GivEnergy's AIO, there's probably a strong argument to suggest if you could only afford one of a battery or solar, is to favour the battery it seems. Just a shame the no VAT scheme doesn't include a home battery at this time

[@GaryDoesSolar]

Thanks for the kind words, Chris. Yeah, this video took a long time to put together, but hopefully it'll help a lot of people. Agreed, I'm hoping the government removes VAT on home batteries before long. If people are prepared to invest £1000s themselves to essentially create a GWh-level distributed renewable storage capability then zero-rated VAT on that seems a no-brainer to me...

[@StefanRosander]

Excellent summary!

[@GaryDoesSolar]

Cheers Stefan 😀

[@terryfollen7902]

Thanks

[@GaryDoesSolar]

Hi Terry, that’s incredibly kind of you - thank you!! 🙏 😀

[@DarkS1m]

Gary, thank you so much for making these clear and informative videos. I've learned so much from you this past week! I was deciding whether a DC or AC coupled battery was best for me, and something struck me when watching this video - the 'triple conversion' with an AC-coupled battery never actually has an effect (providing the battery charges to 100%) since the power is never going to be routed from the inverter into the battery and immediately back out again. Once your battery is at 100%, it only needs to convert the power back to AC once, thus providing the same efficiency as a DC battery would behind the inverter. I suppose the efficiency loss should only be considered 3-fold if the battery wasn't 100% charged during daylight hours (if it makes it to 94% then that 6% did matter). Additionally, charging from the grid would require 2 conversions, so you lose 6% of power if you import to battery from the grid whether using an AC or DC battery. I'm just inferring all this from what I've learned from you, so please correct me if I'm wrong! Thanks again.

[@GaryDoesSolar]

You're most welcome. Glad you're getting something from my videos :-) On the battery conversion fronts, it shouldn't matter what the start of charge of the battery is - the conversion losses should be around 10% for AC Coupled, and less for DC Coupled.

[@GaryDoesSolar]

*** NOTES SINCE RELEASE *** - I've had it pointed out to me that the Tesla Powerball 2 battery is now also capable of level 5 EPS (off-grid) - great 🙂 - Another important factor I could have added is the ability for batteries to prepare for storms, by pre-charging. For example: x.com/teslaenergy/status/1693138247436919214?s=12&t=Xnw8-EENQIi1mPAlIAXH4A - At 6:18 I forgot to mention there is also a DC-DC conversion when the solar power is stored in the battery in the first place - this is because the voltages will be different. The conversion losses for DC-DC conversions are typically lower than AC-DC however.

[@noimnotarobotcanubeleiveit7024]

actually matching the voltage of the battery to the solar string voltage is most efficient. i run 800v

[@colingoode3702]

Another great vid Gary. It just goes to show how fast things are moving. When I signed up for my 4.1kW array, GE 3.6kW Hybrid Inv & 9.5kWr Battery (+ a Zappi & Eddi) last November (which was installed in March this year) I thought I would be good to go for a few years to come. However, the cracks have already started to appear. The GE LFP 9.5kWh battery is probably not big enough for our current / future needs & the 3.6kW Hybrid Inverter is not really big enough to power everything we tend to have running in the house at the same time which requires careful management of what can be turned on & when. I can add an extra 9.5kWh battery to increase storage capacity but I'm pretty much stuck with the Hybrid inverter unless I change the whole system. The GE AIO system was not available when I placed my order last year & is probably the one I would go fo now.

[@GaryDoesSolar]

Hi Colin, thanks! :-) Yeah - technology is always improving (great) but it means that whatever you buy, there will always been something better coming along even a few short months later. I feel the same about my existing GE equipment and the new AIO!

[@buildingbiology]

Very good Gary

[@GaryDoesSolar]

Thank you! :-)

[@odoohub5010]

What i think about the Dc couple battery in 6:04, is that you probably will not max out the 5kw all the time. The inverter will use those extra charge to fill up the DC coupled battery. So it is worth it.

[@GaryDoesSolar]

That’s a good point - although during a forced export period, it likely would. But that won’t be happening a great deal anyway. Thanks for sharing!

[@anthonydyer3939]

It’s a very good summary of all the battery considerations. I will add though that with warranty terms, it is common to see “pro rata” clauses in terms and conditions. So for example if your 9 year old battery is dead with a 10 year warranty , they’ll give you a credit worth 1/10 the replacement cost of your next battery. As for returns on investment. I naively thought this would be easy to measure. It’s not. It’s tightly coupled to your solar investment. So for example: I charge my battery up from clipped solar on a bright day. Then I discharge it in early evening time. So I’ve boosted solar production by 10% in kWh terms, but it’s worth 20% of all value generated for the day (due to flux evening export rate). So: how much of that added revenue is attributed to the solar investment and how much is attributed to the battery? It’s hard to untangle, but it’s an excellent example of how investments boost the value of each other.

[@GaryDoesSolar]

Thanks Anthony. Yeah, like any contract these days, there are always a load of "get out" clauses, which can make the contract not worth the paper it's written on. Somehow, I don't ever see that changing - it'll be social media feedback on how companies deal with warranty failures that determine how they behave... You're right about ROI - I'm about to undertake a ton of research around that, and I'm thinking along the same lines as you - we need to separate out the solar ROI from the battery - not easy! And as you say, there is a combined benefit too - should be fun to untangle :-) By the way, I strongly recommend people to watch Anthony's channel - his latest video on energy pricing and how it might change in the future is highly informative: kzbin.info/www/bejne/g5aTnXl5m7t2rdE

[@leolawless3757]

Gary, I understand the benefit of having a DC coupled battery at 5:09. With the new hybrid inverters and batteries from Sigenergy/Tesla eg Powerwall 3, would it be possible to utilise any of the solar array power to charge the DC side of the battery and also be able to utilise the AC side of the battery to meet the AC demands which are higher than the inverter output? Hope this makes sense. Excellent channel and informative videos😊

[@GaryDoesSolar]

Thanks for your kind words. Yeah, it's interesting that the PW3 can operate in DC or AC Couple mode, but I think you have to select at installation time.

[@CallumMack]

Absolute legend of a channel, thank you. I won't be buying my solar panels and battery for another year but I'm learning so much from your channel. Hoping even Edinburgh's sun can take me potentially off grid 🤞😂

[@GaryDoesSolar]

Hi Callum, wow - high praise! Thank you! :-) I worked in Edinburgh for about 10 years (just off Princes Street) - one of my most favourite cities in the world!

[@mischadebrouwer9855]

Great video as always. Too bad for the UK that Sonnen is not sold over there. Sonnen is big on the mainland (Germany and surrounding countries) as well as USA and Australia.

[@GaryDoesSolar]

Thanks, and I'll check Sonnen out...

[@colinrawlins3286]

Thanks once again for another fascinating video

[@GaryDoesSolar]

Cheers Colin - I'm hoping to create a battery ROI calculator soon, once I figure out all the variables involved (there are more than you might think)... :-)

[@colinrawlins3286]

Looking forward to seeing the google map update to help with checking addresses that would be suitable for solar and when the windmill style solar array would be available.

[@hughrattray9354]

Excellent video - I have forwarded it onto friends who are trying to decide which battery to get. I think there is another factor in making the choice between AC or DC coupled batteries. My DNO (National Grid) will not allow the total of all inverters to be greater than a set amount. In my case it is 10Kw. I have a 5Kw inverter and a Tesla powerwall (5Kw max output) and they will not allow me to add another Powerwall or more solar. They would be happy for me to have a DC battery as that is behind the inverter. It seems they do not trust the power limiters (G100). They have told me the only way I can add AC batteries or more solar is by going to three phase. Keep up the great work.

[@GaryDoesSolar]

Cheers Hugh, and yeah, I think the DNOs are starting to get worried about the increasing numbers of home solar/battery installations. I do believe there is a hardware option to limit export (another box that manages just that) but I don't know too much about it. Worth investigating?

[@MichaelPickles]

My setup is a Victron grid tide / off grid system. There's no solar diverter or EV charging drawback. The system cost was £42k. (Including 14.4 kW of solar) It can output or charge at 15 kW per phase (3phases) life expectancy to 80% is 20 years. Payback using the calculators is 6 years. Sometimes I feel like I built it a bit too big.. was it the best option over a more traditional setups. When you see the cost of those systems and the limitations of single phase. With what's to come with the electrification of houses and cars. I feel like I just have enough to cover the power demand.

[@GaryDoesSolar]

Hi Michael - wow - huge system - but pretty good payback! :-)

[@paulbennett2929]

I wish this video was available before I purchased my set up.

[@GaryDoesSolar]

Hi Paul, sorry I wasn't able to help you in time - each video takes about 50-100 hours of effort, and I've a backlog of over 30 video ideas. Thankfully, my day job is now 4 days a week, so hopefully more time for more videos on what I think is a very important topic

[@Phil-kt6hc]

Love your series Gary - very helpful. I was always leaning towards AC coupled but now I have the tools to explain why. AC all the way baby!

[@GaryDoesSolar]

My absolute pleasure to have been of help to you, Phil - thanks! :-)

[@sampsontendaimutsago1935]

Great insights into batteries. Thanks

[@GaryDoesSolar]

This is really good feedback, Sam - thank you!

[@Leopold5100]

excellent

[@GaryDoesSolar]

Cheers! 😀

[@chrisp7839]

Haven't used a Kettle since the energy crisis began. I use 680W Instant Kettle Urn. Use cheap rate to heat (charge up) the urn, and then during the day it uses 2W to keep the water hot. It keeps the water at 98C, if you really need it boiling, a few seconds in a jug in the microwave will boil it again. Toaster is 800W, caravan toaster. Hob is a 2 ring 16A induction hob. This has meant that now a 5KW inverter is generally able to supply power from the battery all day without drawing from the grid, even if using the oven.

[@GaryDoesSolar]

Very good.

[@kierank01]

Would be great to get a list of inverters that are supported in home assistant....it's really hard to make a decision on which to get, and then you need to get an installer that actually supplies them

[@GaryDoesSolar]

Agreed, and I don't know where you'd get such a list from - I don't know too much about HA yet, but it's something I'm interested in learning about if I get time :-)

[@ianbeck5897]

A nicely put together video Gary and, having watched it right through, it covers pretty well everything that came into my mind when we chose to add a battery to our system a few months ago. Much of my decision making process in specifying the system was as a result of videos from yourself and others (and my electrical engineering degree came in handy too). It's very reassuring to see that what we chose in the end is well aligned to your video content here - but chosen to suit our individual needs. So far, we're happy with our battery addition and having Octopus Agile as our tariff means that we can keep our batteries nicely topped up but without over stressing them. .... AC coupled 15KWh Phosphate batteries (3 by 5KWh each), for information.

[@GaryDoesSolar]

Hi Ian, thanks - and great to hear I managed to cover all the salient points :-) I studied Electrical Engineering too (but I think I've forgotten most of it!) - helpful for all this solar and battery research though :-) Your battery strategy sounds good, and not a bad capacity!

[@gordon6029]

Awesome Gary. Thanks for this.

[@GaryDoesSolar]

My pleasure, Gordon. Glad it was useful to you 👍🏻

[@anisotropicplus]

Great video! Tons of excellent information!

[@GaryDoesSolar]

Thank you! 🙏 😀

[@MichaelPickles]

From my own research for the UK and actual use in my area. Normaly it's 10 kilowatts export limitation on a single phase. This is normally the maximum size they want you to have on a solar array or inverter. You can times that by three for three phases. It would be great if you could do a video on the Victron grid tide system. I believe my DC to AC conversion rates are about 1% the same again back. Making a 2% loss.

[@GaryDoesSolar]

Didn't know the conversation rates were so low on Victron!

[@wemorgan]

I'm looking forward to your battery ROI video. Like you, I've tied it myself and generally see that for the "average" kWh user, batteries are an expensive option. But for higher energy users, maybe those with ASHP, then battery % utilisation is high and therefore more cost effective.

[@GaryDoesSolar]

Agreed, and I'll try and get round to that video very soon (it's 3rd in the queue at the moment)...

[@wajopek2679]

Another well put together video. Whether you are technically competent or novice, these series of progressive educational videos are a must or as a reminder for anyone starting out down this rabbit hole. Gary. Can I send you an email on a PV /inverter subject which might interest you in a future video?

[@GaryDoesSolar]

Thanks for the great feedback! And yes of course - please send to [e-mail] :-)

[@keithjohnston1981]

Another great video. Thanks. I’m looking forward to my additional 3.32kw array and three solax triple batteries (15.66kw usable) being installed on Monday. This is to supplement my existing 3.92kw array on the 2012 FIT scheme.

[@GaryDoesSolar]

Thanks Keith - and your new array sounds pretty good! I think you'll enjoy the batteries as well :-)

[@dansmith183]

Love it, thanks Gary!

[@GaryDoesSolar]

Cheers Dan - great to hear! :-)

[@konstantinazisi2246]

How about BYD batteries with fronius charge inverter for AC coupling? In Greece up to a few weeks ago one could apply for net metering instead of net billing to the effect we don't care about pricing during the day. Also, for some reason, pretty much everyone seems to buy BYD.

[@GaryDoesSolar]

What was the different between net metering and net billing at the time?

[@ians3328]

I have a GiveEnergy AIO which is not big enough. They said we would be able to stack many together (like Tesla) but many months later no idea when ! Would putting a DC coupled battery be better just to add a little more capacity - or would the control of it be hard work. I don't want the hassle of Home Assistant. Only really need 6kWh and I am guessing that the additional AIO will have the full 4 batteries in them hence twice the size and cost.

[@GaryDoesSolar]

Hi Ian, worth watching this video from Speak To The Geek which might answer: kzbin.info/www/bejne/gmSnm5ikpLd-rbM

[@robjones8950]

Keep them coming Gary. I’m planning to hammer my (expensive - how does Giv Energy do it so cheaply?) SE battery even more this year as I’ve just installed a heat pump and will be using the Cosy tariff this winter. You didn’t mention V2X. I’ve decided against a second battery to see how V2X develops.

[@GaryDoesSolar]

Hi Rob - thanks - I'll keep the videos coming (each one is a ton of work though - I need to get more efficient somehow!) Yeah, I'm watching V2X (particular V2G) closely to see how it develops.... Yeah, keep hammering your battery - I'm doing the same with mine! :-)

[@Ben-gm9lo]

I concur, another cracker from our man Gary. Thanks so much. We have a solar/battery install coming in Sept with 2 x SE batteries. I plan to move from gas to heatpump next year for heating/hot water and the 19.4 kWh storage should allow me to run the whole house, inc space heating and our 2 EVs on 7.5 p overnight electricity. Sounds too good to be true!

[@dennydewaal137]

That is wye I chosen a 51,2v 70kwh battery Tesla model s. Battery type ( I got the Panasonic bd and ga so they are a little better than the Panasonic ncr/b Tesla uses, just so I can have the same experience of 32 years of the battery life ) ad the end it’s all about choices. !

[@GaryDoesSolar]

So true! And it sounds like you made a good choice!

[@John-FourteenSix]

Excellent. Well thought out and informative. Home assistant looked interesting. Would / could this show an ASHP and Zappi EV charger integration? This would make an interesting video. You didn’t mention the GivEnergy Gen 2, 9.5 kWh battery and Gen 3 Hybrid inverter, but that’s just me.

[@GaryDoesSolar]

Thanks John - really great to get this feedback! Regarding Home Assistant, I thinking of reaching out to "Speak to the Geek" to do something jointly on this...

[@John-FourteenSix]

@@GaryDoesSolar Sounds good.

[@drharis]

Hi Gary Recently stumbled upon your channel as i am thinking of installing solar. One of the best channel i foujd so far. Very informative and easy to understand. Thanks! I saw you mentioned home assistant. Do you know if enphase battery systen can be integrated with HA. I can see a enphase envoy integration in HA. Not sure ot is the same as enphase battery system. Once again thank you!

[@wendygrant2735]

A lot of great intel in this video again. I'm wondering if it's worth the money to choose for a bigger output inverter, let's say 8kw instead of 5kw, for your needs in the house. Then you can choose DC coupled batteries and minimal losses. Right?

[@GaryDoesSolar]

Thanks :-) And I wouldn't worry about the losses - although theoretically, losses for DC Coupled batteries are less than for AC, in practice, it doesn't make that much difference... And of course, a bigger inverter could be refused by your DNO (or export rate limited)...

[@TommysDaddy]

@@GaryDoesSolar I think you can get bigger inverters within G98 if they are 3-phase ( as each phase would have a separate 'limit'. am, I right? ) . I have 3-phase to the house.

[@GaryDoesSolar]

@@TommysDaddy Good question - and one I don't know the answer. Would be great if so! 🙂

[@stingk5295]

Great Information

[@GaryDoesSolar]

Thank you! :-)

[@TomKrysiak]

Great video, I've GIV-Bat8.2 x2 but can't find any EPS related info anywhere. Not on the product sheet, not anywhere else on their website. May need to call back the installers and ask there...

[@GaryDoesSolar]

Hi Tom - thanks for the kind words. Might be worth reading this, which covers EPS setup. Will be inverter model dependent: givenergy.co.uk/wp-content/uploads/2023/08/Gen-2-Hybrid-Inverter-Installation-Manual.pdf

[@dominicherity3605]

Great videos! They make complex issues clear. I'm puzzled by a discrepancy in reported battery prices. In this video, you list batteries with cost/kWh ranging from $700-$1350. But in your other video, "Home Battery Prices Are Falling!", there's a graph showing $120/kWh in 2024. What have I missed?

[@GaryDoesSolar]

Hi Dominic. The discrepancy is all about the pricing of battery cells compared to the pricing of battery packs. The latter is much more expensive because of manufacturing, marketing, sales, distribution, customer support, consumer sales taxes etc.

[@livingladolcevita7318]

Thanks Gary much to consider. I am woefully under informed on my system. I have already got batteries maybe DC coupled need to check, in my loft, and something that has me concerned since I watched the electric viking in which he states that batteries are not allowed in roof spaces in Australia not sure about the UK. Not sure whether mine are LFP or other.

[@GaryDoesSolar]

You're most welcome! In the UK, I don't think there is legislation preventing batteries in the loft, but that might change in the future. To me, it's all about the absolute number of house fires (that will make the papers) - which will increase as more and more people get home batteries - rather than the percentage.

[@andytaylor6893]

Hi Gary, great channel 👍 Any tips on how to integrate a battery with a heat pump? We also have 4kwp solar and 2 EVs. The challenge being that we have very little control over what the heat pump does and when it does it besides forcing it to heat the hot water for washing during the Octopus Go cheap period.

[@GaryDoesSolar]

Thanks Andy. Essentially with regards to the battery, it simply supplies whatever the home needs (as far as its charge allows) - even if the home includes a heat pump.

[@nigelhamilton-brown1918]

What are the safety risks of keeping inverters and batteries in the home?, for example use the roof space?

[@GaryDoesSolar]

I certainly wouldn’t be comfortable keeping an NMC chemistry battery anywhere in my home. But everyone’s attitude to risk is different.

[@RahulParmar1978]

This is one of the best explanations on KZbin on the topic, thanks! You mention that hybrid inverter can result in the unwanted outcome of battery discharging into EV but that there is a way to mitigate this outcome. What is the solution? (I've signed up to your Patreon!)😃

[@GaryDoesSolar]

Hi Rahul, thanks for your very kind words - that's such great feedback to receive! And thank for signing up to my Patreon as well - very much appreciated :-) One way to mitigate is to let the inverter controlling the battery see the power (via a CT clamp) going to the EV charger. Here are some videos on that topic: kzbin.info?search_query=solar+battery+discharging+into+EV

[@RahulParmar1978]

Curious to better understand the real world impact of DC coupled battery being limited by inverter capacity? Looking at my energy demand in Home Assistant 96% of my readings are sub 3.68kW (ignoring EV charging sessions). Even with an ASHP demand is likely to be under 5kW the vast majority of the time. Is this really something to worry about?

[@GaryDoesSolar]

@@RahulParmar1978 Yeah, it's pretty much the same percentage ratio for me (85-90% anyway) so actually, is it really worth worrying about - probably not...

[@robertbarr6388]

Superb.

[@GaryDoesSolar]

Thanks for the great feedback, Robert 🙏😀

[@richardepping9748]

Great video. Learned alot 😎🤙🤙

[@GaryDoesSolar]

Cheers Richard - happy to have been of help :-)

[@stephenbrickwood1602]

Rondo Heat Battery are a new industrial heating technology. Very high temps, 1,500⁰C upper limit. A domestic version would be possible. Accumulate anytime solar during the day and off peak at other times. Have a look, jusy my thoughts. 😊😊😊

[@GaryDoesSolar]

I'll check it out, thanks.

[@IanB61]

Excellent video Gary. Thanks for all your hard work. The GE certainly seems like a good choice in the uk, but my concern is the need to have a separate dc inverter from solar. Would it not make sense for the GE ( or any other manufacturer) to have a hybrid inverter built into the unit. As these setups become more common I think most people would like a one box solution with minimal "clutter" in the garage or wherever

[@GaryDoesSolar]

Ah now, my understanding is that the inverter is built in to the AIO unit. Happy to be corrected on that though! It’s the EPS Gateway that’s separate - fairly typical of other manufacturers AC batteries too. Thanks for your kind words on my video 😀

[@locmer1970]

I got solar a installation when my house had a 1 phase 40 amp power mains. For my electric car I switched over to 3 phase 25 amps. But now I have solar on one phase. I think when choosing a solar setup and battery in combo with 3 phases, it changes things. And I think more people rapidly will find themselves in this situation. A video on this would be helpful.

[@GaryDoesSolar]

I might tackle 3-phases one day, but I'm trying to concentrate on video topics with the widest appeal for the moment - not everyone has 3-phase, unfortunately...

[@odoohub5010]

Rather than having an AC coupled system, to increase capacity. Could we still have a DC coupled system, where a second solar inverter with its own DC battery, is setup up to be in parallel with the frist solar inverter, in order to increase the power capacity to the household appliances?

[@GaryDoesSolar]

Yes, that would work - and it was something like considered for my own installation (I currently have two DC Coupled batteries on one inverter) but decided again. I do sometimes draw more than the inverter limit but it’s not that often…

[@philipholme9911]

The advantage of a AC connected battery is that if your client is in reciept of the feed in tarrif thety can keep the money made from the FIT. Regards Philip, Apollo Solar Energy Ltd.

[@GaryDoesSolar]

Thanks Philip - good point, and one I didn't make in the video as it only applies to those lucky enough to get o the FiT scheme. For me, AC Coupled batteries are just way more flexible than DC Coupled.

[@philipholme9911]

i tend to install DC connected battery systems on new installations and on retro fit installations i fit AC battery connected systems.

[@geoffreycoan]

Another very clear and comprehensive video Gary, thank you. The charge/discharge rate of the inverter and the battery are for me one of the key decision factors as to whether you can use your battery effectively to power your home. You mentioned that a benefit of AC coupled is that you can chain multiple batteries to increase the throughput, you can do the same with DC coupled as well if you have multiple hybrid inverters. I have two GivEnergy Gen 1 5kW hybrid inverters which were sized this way because of the number of panels I was having installed. Looking at the energy graphs I am not getting anywhere near clipping on the inverter output, but if I’d had one inverter I definitely would have been clipping. Two inverters means double the charge & discharge rate. Another battery choice consideration is whether you can expand the batteries yourself. Most manufacturers allow this and the batteries just plug in, GE are the outlier by insisting that the install has to be done by a qualified installer. This is a disadvantage of GE. And a minor point on the GE Allinone, their literature says the ‘up to 6 batteries’ chaining is a ‘coming soon’ feature. GE’s multi-inverter option for AC and DC inverters has been work in progress for a long time, so hope its coming sooner for them to compete with Tesla

[@GaryDoesSolar]

Thanks Geoffrey - really great feedback :-) Thanks also for sharing this insight - and yeah, I read the same about the AIO - hopefully, that feature will appear soon!

[@robertcatanzaro2982]

Excellent channel Gary. Can you consider the cost / ROI on just buying a battery and not solar to go with it. With for instance Octopus Intelligent charging 0.075pkw is it even worth the hassle of funding & installing Solar? (I have a Grade 2 listed building appreciate it's still possible to have Solar but it's complicated). BTW I love solar, have over 200kw on a property portfolio plus three EVs in the family. But is just spending the money getting a bigger battery and paying a utility it's due to supply and manage the ins and outs "a" way forward. Also note 3 phase can be available for 4k.

[@GaryDoesSolar]

Hi Robert, thanks for the kind words. Yeah, I'm planning to do just that - working our ROI just for the battery, isolating it (as far as possible) from the solar ROI. It's not an easy thing to do, but I hopefully will come up with something useful... Ok, that's clearly some property portfolio - well done! And great that you've got so much solar on them :-)

[@jonathankeenan5163]

Thanks Gary these have been hugely useful! To add complexity we have decided, due to a number of factors, not to get solar installed. Instead we invested in Ripple Energy's next scheme which is a solar farm. Once online this will provide a rebate on our electricity usage. To complement this I am looking at a home battery, hence my interest. I suspect this twist in circumstances could be worthy of a video in itself. Especially as I imagine many other people are looking at battery combined with special tariffs as a quick way to help the transition to cleaner energy. There may even be a good argument this should be the first step rather than a bolt on after getting solar?

[@GaryDoesSolar]

Hi Jonathan, thanks - and really great to hear that you're getting a lot of my videos :-) As it happens, I covered Ripple in this video: kzbin.info/www/bejne/qqewi3WimdOkoZo - it's a great way for people to get into solar, without having to install it on their own homes. And I plan to make a video soon on battery-only home installations - I just wish the UK government would abolish VAT on such...

[@jonathankeenan5163]

@@GaryDoesSolar 100% agreement on VAT removal/reduction. Your video analysing price drops for solar making payback potentially quicker if we wait a year or so was one of the many reasons for not installing now. I'm focussed more on the environmental arguments (but with a realistic approach to cost) so a combination of Ripple, some Octopus Energy tariff and a battery may be the best environmental impact for the least medium term cost. We have a survey for air source hear pump on Monday which may lead to yet more complexity! Solar may come later if/when cost reduce further. Thanks again for all your hard work.

[@GaryDoesSolar]

@@jonathankeenan5163 Yeah, prices are certainly coming down (finally!) so hopefully you'll benefit well from that. How did your ASHP survey go, if you don't mind me asking? You can email me on [e-mail] if you prefer...

[@jonathankeenan5163]

@@GaryDoesSolar Survey went well (I think). There were close shaves on the size of the property and a few microbore pipes as we've had various work done over the years but the real deal breaker was almost our water pressure; apparently utilities routinely turn it down rather than fix leaks. This explains the terrible showers.. It's a lot to take in. The survey was Octopus and the quote was remarkably good but I now have that irritating know-just-a-bit-too-much to be able to make their lives a misery asking details. Things like the spec for the water tank and calcs for heat loss and pump size etc. I get the feeling they have gone for simplicity and low hanging fruit approach to really get ASHP moving by getting the cost right down. I just need too make sure the simplicity is a marketing thing not a compromised system planning thing. Our gas boiler is on its last legs so the timing is perfect and the cost about the same as a new boiler instal. I need to find out more about how much impact a battery alone would have relating to the ASHP but that VAT is a killer and could almost be enough to justify adding solar, but it's always easy to find new ways to spend even more money.

[@GaryDoesSolar]

Hi Jonathan, sorry for the delay in replying - lots going on at the moment. Thanks for letting me know about your survey. Ok, sounds pretty good then - and agreed, better to be well-informed on the tech than not! 🙂even if it does make life difficult for the suppliers - there's too much money, effort and change involved! Hope all goes well with whatever you dicide (or when your gas boiler decides for you)!

[@RayBrint]

I understand most everything you have put forth. What I cannot seem to grasp is how to throttle charging and discharging the battery as to production and consumption. Buying an electric car that can be used as a battery seems very cost effective. How do I stop it from discharging at a rate far faster than needed so as to not pump it into the grid?

[@GaryDoesSolar]

The battery management software will do that for you. It can sense when energy is being exported to the grid and throttle back discharge.

[@Mits1230]

Gary, great informative videos. Do you have plans to do a battery without solar video. I am really interested about advice on what to get in this regard? We are projected to use over 6500 kW of electricity per year.....

[@GaryDoesSolar]

Thanks for your kind words - I certainly do! I'll likely wait a few weeks though to see if prices come down further - that's critical to make a battery-only solution work...

[@rabbit9696]

Great vid Gary and very clear explanation thanks! Question- can we mix a DC and an AC battery in the same home system in the UK to get the best of both?

[@GaryDoesSolar]

Thanks for your kind words. I mean, you could, but unless you have supervisory management across both batteries together, you’ll likely find that one battery drains into the other :-/

[@samuxan]

I've been planning about getting a battery for a while and I have it down to 2 options but the difference wasn't covered here. One installer offers me a 5kw battery and the other one has a system of 3 1.8kw batteries connected. The overall capacity is almost the same and what the one I need. And price is fair in both cases. But I haven't found reliable info on whether is better to have many smaller batteries or just a bigger one.

[@GaryDoesSolar]

Worth looking at the depth of discharge ratings of both solutions, and the overall charge/discharge rate. Personally, I'd go for a larger single unit rather than multiples small ones.

[@chrisclague5578]

Brilliant video. It would be good for you to cover Pylontech batteries with chargers as these are good and it is easy to increase the storage capacity

[@GaryDoesSolar]

Hi Chris, thanks for the great feedback. I nearly went for Pylontech batteries myself - I really like the modularity and cost-effectiveness of that solution, but I don't think my wife was enamoured with the aesthetics.

[@TommysDaddy]

BYD is another modular battery that I have seen KZbinrs talk about

[@harryfettes393]

Is there any technical reason why a battery couldn't be DC coupled for PV charging and simultaneously AC coupled for discharge and charging from the grid?

[@GaryDoesSolar]

Hi Harry, I'd say yes - it's either behind or in front of the inverter, so would require extra hardware inside the inverter to make that happen I guess... but for what advantage?

[@harryfettes393]

@@GaryDoesSolar Efficiency/Utility. You would save one AC/DC conversion on solar charge and be able to utilise surplus solar without impacting AC to the house. You would still be able to augment the solar AC with the AC coupled battery connection and support higher power island mode in the case of a grid failure. Is there much difference in cost between a hybrid and string inverter? Does the battery care where it gets it's DC from. Maybe this isn't a thing but could it be? BTW joined Octopus with your code today💷💷

[@GaryDoesSolar]

@@harryfettes393 I see your thinking - yeah, could be something in this 👍Hybrid inverters are typically more expensive than non-hybrid, certainly. Thanks very much for thinking of me with my referral code - that means a lot! 🙏

[@lancalotspratt]

Hi, I have a 7.5Kw Diesel generator which when off grid will run the home @12 Hrs per gal .

[@GaryDoesSolar]

Yeah, for some, having such a capability is essential 👍🏻

[@Neo8019]

In Germany you are not allowed to charge the battery from the grid or discharge the battery to the grid. So the AC coupled batteries have to reduce power to 0 if you have enough power from PV or at times where there is noting from the PV and you are using couple of 100s of Watts at home then the batteries must only cover that. At least the grid providers in my area are like that. Some other parts in Germany that might not be the case. I will be installing Enphase batteries 1 for each phase. Next week its delivery time. 😁

[@GaryDoesSolar]

Thanks for this information about German energy policy (in your area at least) - I didn't know that. The policy does seem quite restrictive, especially in light of the fact that many countries depend of displaced energy via batteries to support everyday operation of the grid. Why not extend to domestic situations? Good luck with the install next week! :-)

[@Neo8019]

@@GaryDoesSolar The bureaucracy and all the regulations in this country can be so restrictive that makes you want to pull your hair out and give up. They are getting better but still a way to go. At least as of 01.01.2023, there is no VAT on the equipment and installation. But yeah it's crazy. I'm allowed to feed the grid directly from the panels but not from the batteries. Go figure. Thanks about next week. Lets hope it all goes well. 16 Mayer Burger are going up together with Enphase IQ7A Microinverters and also the batteries.😁 And keep up the good work. Great and informative videos. P.S. If you are interested I can keep you posted.

[@olafschermann1592]

I decided for 6kw solar, and 12kw hybrid inverter and a 30kwh 48V battery (costs 1/8 than HV batteries when self built). so i can charge my EV with 10 kw even in the night

[@GaryDoesSolar]

That's quite a setup, Olaf! :-)

[@odoohub5010]

I think AC coupled system is a gloryfied version of multiple parrallel inverters connected to DC batteries

[@GaryDoesSolar]

Hadn’t thought of it like that.

[@angusmcbraith]

Very good

[@GaryDoesSolar]

Cheers! :-)

[@delprice3007]

A bigger inverter discharge would benefit DC coupled battery ?

[@GaryDoesSolar]

I'm not sure I understood your question. Could you rephrase please?

[@greenfrog58]

Really a great video! Byd battery ?

[@GaryDoesSolar]

Cheers! I only included what seemed to be the most popular batteries at the time. I could easily have added others...

[@MrKlawUK]

with respect I think the instantaneous graph is a little ‘blunt’ suggsting high peak for several hours. Most of the time I’ve found high demand is more spiky, only a few minutes at a time. Even running dishwasher/tumbledryer/oven/kettle they often are at different phases of heating cycle or simply don’t run for long. I’d be curious to understand more on this - perhaps a way I can measure peak load on my home. Logic tells me a 3kw would be fine, but I can’t deny I have been looking at the Givenergy AIO’s 6kw with some envy :) - but I already have a 3kw givenergy

[@GaryDoesSolar]

Yeah, that graph is likely not representative of the reality for many - it was emphasised for the video. We breach the 3.6kW output of our GE batteries more often than I'd like, and the AIO or PW3 would solve that for us! One day (sigh)...

[@MrKlawUK]

@@GaryDoesSolar I have one 9.5 givenergy. I probably want another in a year or two. But I wonder if I could sell my current and buy an AIO for around similar overall cost? Is there a market for used home batteries?

[@GaryDoesSolar]

@@MrKlawUK I would buy your 9.5 from you, but unfortunately, I don't have room for it! Yes, there is a secondhand market - for example, eBay: www.ebay.co.uk/sch/i.html?_nkw=givenergy+battery&_sacat=0

[@MichaelsKarish]

Isn’t EPS a function of the inverter especially on DC coupled systems

[@GaryDoesSolar]

It likely depends on the manufacturer. My GivEnergy system has a DC Coupled battery and I have some electrical circuits on EPS. The inverter seems to take care of everything with GivEnergy at least.

[@oliverpower7155]

You’ve done it again Gary! Keep up the good work my friend 👍🏻 do you know would would be required if you wanted to make any of the batteries EPS off grid rather than whole house?

[@GaryDoesSolar]

Thanks Oliver :-) You'd need to check with the manufacturers - they determine whether the batteries can be used in an off-grid scenario (level 5)...

[@robwalker6167]

Thanks Gary - great video. Trying to put together a budget for PV + Battery + ASHP which is a challenge. My first 'Google' after your video was on the Franklin WH aPower, but it looks pretty sparse out there in the UK to find an installer. Can you share any suppliers? Have you ever done a video that balances the kW capacity on Solar generation and Battery storage/supply? I think I can fit 13 panels on my roof so probably around 4.5kW capacity, but your video on charging the battery at night off the grid was a total revelation to me. Now I'm thinking the battery size choice should not be limited by my PV array.

[@GaryDoesSolar]

Cheers Rob, for the kind words. Now, I'm not aware of any FranklinWH distributors in the UK unfortunately, but perhaps others might know...

[@davidreece1642]

When charging an EV, there needs to be smart comms from the charger to the DC inverter that prevent the DC battery from discharging preferentially, which would address that particularly issue. Sadly, I've no idea how that might be done. Great explanation of the tech as always.

[@GaryDoesSolar]

Thanks for the kind words, David. Agreed, and until there are standardised interconnection protocols in place (who knows if/when they will ever come) then I understand that there is a workaround: support.myenergi.com/hc/en-gb/articles/4716922623633-Hybrid-PV-and-Battery-How-to-stop-your-myenergi-devices-draining-the-battery-in-ECO-

[@madharry6792]

I need solar community’s help. I have solar panels for 5 years now and doing a great job! But my research on trying to get the right battery (LFP for longer life and fire safety I think?!), a practical fuss free app, a decent installer and competitive pricing has failed time and again. Even if I find one installer their trustpilot reviews scare me away. So my question or a mini survey for the solar community in England or Nationally- who did they find who consistently gives good service, has latest tech, and did not cost an arm? Much much appreciated

[@GaryDoesSolar]

Hi Harry, I recommend you sign to to this group on Facebook. You'll find a lot of information that I think will help you, and you can ask questions there as well, as there are many experts and fellow enthusiasts who will respond: facebook.com/groups/2197329430289466

[@conradmcbride]

Great video Gary!

[@GaryDoesSolar]

Thanks :-) Glad you liked it.

[@GroupCaptain-LionelMandrake]

DC coupled batteries outputting to the solar diverter and the EV charger. Why is that a negative? You mentioned that 10.30min just curious? Thanks

[@GaryDoesSolar]

So, on the basis that you’d only want to charge your EV with off-peak energy, you’d want to draw that energy directly from the grid. But if the battery doesn’t know any better, it will see this grid draw and discharge itself to minimise that draw, defeating the purpose.