Adding AIO to existing installation

I have a similar set of questions to the ones posted a few days ago on expanding an existing installation. At the moment I have a Gen 1 AC inverter with 9.5kWh battery, along with solar panels feeding a 6kW Solar Edge inverter, and a myengergi Zappi and Eddi. Charging the EV and the battery overnight on Octopus Go, in the winter months the battery is often fully depleted by mid afternoon. I would therefore like to increase capacity so that this does not happen, and store more of my solar production in the summer across multiple days, and future proof for a heat pump install. In addition, I would like to have battery backup available when there is a power failure. I tried to get my supplier to exploit the EMS on the current inverter using manual changeover, but they never figured out how to install it.

One option would be to add another battery to the inverter, but that is a dead end and does not provide failover capability. A second option would be to install an AIO and gateway, which seems like the best option, but I have a number of unanswered questions, even after speaking to Givenergy on the phone.

Just to note that I am likely to be limited to the 17kW single phase limit on inverters by the DNO, so I need to find an option that does not add massive inverter capacity that can potentially export to the grid.

1. Is it possible to add additional battery capacity to the AIO without adding another inverter? (hence taking me over the DNO limit). Please see this other forum post, and in particular the video interview with Paul Landregan (Givenergy head of product development).[https://renewableheatinghub.co.uk/forums/energy-storage/givenergy-2025-forthcoming-batteries-and-inverters]. Listen to what Paul says at 7:15 onwards which suggests that storage can be added without more power (from additional inverters).

2. Is the AIO product that he is talking about the one that currently available, or is it one that is yet to be released? (I noted a comment in another post which implied that a new version was still to come)

3. If I add an AIO am I going to run into cross-charging issues, and if so, is there a sensible approach to preventing this?
   I have a HA install running already, but have not recently made use of an early attempt I made to use GivTCP.

   4. Are there any other potential gotchas that its worth knowing about?

Any advice would be warmly welcomed.

Speek-to-the-geek did a very similar thing with his own setup, but it relies very much on HA: [https://www.speaktothegeek.co.uk/2023/11/using-a-givenergy-all-in-one-and-ac-coupled-inverter-together/]

Arron Thanks, I believe I watched that previously. However, the approach he took in that video is now not recommended, please see his video on "Is Predbat Breaking Inverters". He suggests that the Givenergy EMS may eventually solve the problem, but that raises another question as to whether the EMS works now (or might in the future) with both older AC coupled inverters and the AIO.

The low and slow approach is the alter the

Set one of the inverters to discharge at say 300W (if your usual base load is less than that, then set it to discharge at a lower value)

Tell it to pause discharge if there's a big yellow bright thing in the sky, to reduce risk of cross charging if it hides behind a cloud and then appears again. I think watching the mains CT for export and pausing might be the answer to that bit.

Tell it to charge during the off peak rate.

TX200 Yes - thanks - that is what speaktothegeek said in his updated video on predbat.

Peter4H Just found the quote about a potential AIO update: @geoffreycoan said "there is an AIO2 coming apparently"

Bump......any thoughts on my Q1 and Q2? i.e. are we going to see the option that Paul L appeared to describe, of being able to add storage without additional inverter capacity? Is this planned for in a further update to the AIO? I am currently unsure where we are with revisions of the AIO: are we already at AIO2?

Peter4H I believe we are still on AIO v1. After the initial 6kW AIO launch there was a 3.6kW version of the AIO which would fit with G98 regulations, but this is just a de-rated AIO not a new product.
There’s then the beta service of multiple AIO’s controlled via the gateway, but again, same product.

There’s AIO2 is anticipated to have features similar to the Tesla Powerwall 3, like inbuilt PV inverter, but when it will be available, no idea. First real idea is when it starts appearing on the GivEnergy stand at shows like Everything Electric, but that could be weeks or months (or even next year) away. Maybe checkout videos on YouTube.

Not heard anything at all (ever) about adding extra storage to the AIO. Would make sense but does rather break the “everything in one box” concept of the AIO. Does the AIO even have external battery sockets to facilitate such an upgrade?

AIO 2 will have a PV inverter in it (thus actually making it an AIO in my eyes?)
Equally the YouTube crew have mentioned it would be expandable without buying the aio inverter stuff again. I suspect (&this is just me guessing how I'd do it) that additional storage for the AIO2 will take the form of the HV battery stacks already available and they will plug into some of the spare mppt inputs on the AIO2.

geoffreycoan Thanks - that supports my assumption too i.e. despite suggestions in the videos that the new version would already be with us, it isn't, and its difficult to determine when this might be the case.

I would also assume that the new version of the AIO would have some additional connectors to permit additional HV battery stacks to be added.

hoggy Agree, I am sure this was mentioned in the videos. Its not clear whether additional HV battery stacks would plug into existing mppt inputs, or whether some additional new connectors would be required.

geoffreycoan I was considering the 3.6kW version of the AIO, as this would enable me to stay below the 17kW DNO limit. However, I really wanted to have the option of adding additional storage later, and if the 3.6kW product is just a de-rated variant of the current AIO, then this is another potential dead-end given that having parallel AIOs would again put me over the DNO single phase limit.

Peter4H I think you'd be better waiting to see what the AIO2 looks like if you want to expand the storage. Hoggy suggested the extra battery packs may only be for the '2 model?

geoffreycoan This is what Paul L said in the interview:

_The new AIO hybrid, or as I call it, the AIO 2. Its official name has not yet been announced. This is a 12kW inverter, so its doubling the current inverter power. Your battery is remaining the same at 13.5kWh. As you say its a hybrid, but its also an AC coupled, the hybrid is optional. If at a future date you want to add the hybrid its just a module that sits on the top.

.....There are plans to run them in parallel, that's for future stages. You will from launch be able to add a second battery, which is what people want. With the current AIO they don't necessarily want the additional power which is nice, they want the extra storage. So rather than being able to add batteries to the original AIO, with the new AIO you will be able to add DC modules._

Peter4H Thanks. Does sound like it leaves the existing AIO(1) customers out in the cold without adding extra storage as an option, and a difficult decision as to whether you want multiple AIO capacity whether to go with the AIO(1) which has it, or wait for it "at a future date" for the AIO2.

We shall see. It would absolutely make sense to make use of the high voltage battery packs that are common with the 3 phase hybrid and new 8/10kW hybrid inverters.
Maybe the AIO2 is an AC-coupled plug-in for those batteries, thus bringing consistency back between the AC and hybrid product lines as there was with the original AC3 and 3.65kW hybrid inverters and low voltage batteries.

https://www.pv-magazine.com/2025/02/19/givenergy-launches-gen-3-hybrid-inverters-for-pairing-with-stackable-storage/

PianSom https://community.givenergy.cloud/d/5622-8-10kw-hybrid-inverters-with-10-80kwh-high-voltage-stackable-batteries

The AIO2 will be able to be set to any power level your DNO requires between 3.6 and 12kw.
Storage is DC bus connected and is expandable. Right now were saying 3 expansion packs, which MAY change before launch.

The AIO1 can be paralleled upto 3, each set 3.6, 4.6, 5, or 6kw. again expanding storage with not much effect on inverter power.
Even then you can adjust the inverter power in 1% steps as you wish.

The Hybrid, and presumably AC and AIO, have a setting for maximum permitted grid export. It wouldn't be too great a change, to have the setting control grid import as well as export. Wouldn't that get around any DNO issues?

mrand31
There are 3 parameters they look at
Export, Import & Generation capacity

They use the generation capacity figure, as export & import limitations have hysteresis times of upto 15s to respond. Giv kit is under 5s if not even faster. But they dont care for that. the kit could export large amounts for a short time and disturb the grid.
Example, your 10kw inverter is powering your house, say the 10kw shower.
The shower stops. Now that load isnt there no more, and will go to grid instantly.
The meter responds, sends signal to the inverter, it responds by ramping down the power to maintain the required levels.
Its this burst of export that they care about

TheDragon (GivEnergy) That's a great explanation. Does that mean then, if you have an export limit which is less than 2 battery inverter outputs, you wouldn't be able to connect a second battery?

As an example 2 * 6 kW AIO (v1) and export limit of 8kW

CW depends on the local infrastructure can take the 12kw for a few seconds.
THen it will be accepted and export limit 8kw set.
If local infrastructure so fragile that this burst is not tolerable, generation limit will be set

TheDragon (GivEnergy) moot point as I don't have any AIO but if say you had multiple AIO but software limited down because the DNO is being a wimp, does forcing island mode remove said limiter, or is it persistent across both operating modes?

TheDragon (GivEnergy) Sorry, whilst this is helpful it still leaves some uncertainty. Is the inverter effectively software limited to whatever figure is set, which means there is a a certain response time, within which a large load could be dumped to the grid? So are we effectively limited by the 12kW potential of the hybrid/AC coupled inverter, implying that all other inverters in the home can't add up to more than 5kW? If this is the case, then I would already be over the limit just with my PV (6kW Solar Edge). Am I also correct in assuming that adding additional DC modules is not an issue, because this is not affecting the inverter capacity?
So could one option for me be to ditch the Solar Edge inverter, connect the PV into the new GE inverter, and run these in parallel with the existing GE AC coupled battery and inverter? So that would be 12 + 3.6 = 15.6 kW.

Peter4H thats a question for your installer to design your system