I’m a new user and have tried to setup so battery charges up between 2am & 4pm and then discharges between 4pm and 2am. Discharge mode is Scheduled and Consumption Type set to Home Demand. But when I check the Dashboard I can see it pumping out about 3.5kW to the grid. Only way to stop that seems to be to set Discharge mode to Dynamic.
Have I misunderstood how things work? Or is there an issue with the app / settings?
Thanks in advance for any guidance!
I have exactly the same issue as a new user. I have the AIO and trying Scheduled Discharge and Home Demand productes 6kW out to the grid less any local demand. From this I suspect that this is the design. The question remains how to do what we want. The documentation is scant. One possibility if it works for your tarrif and usage is to us a combination of max charge % and time. Once the battery hits the max charge % it stops charging and the grid supplies the local demand. So perhaps leaving the discharge mode on Dynamic and extending the charge time until you want it to dischage? It’s a workaround but I’m thinking of trying it until I figure out a better way. There is of course the automation approach but that needs more effort.
There’s also some info here Battery Management with Octopus Smart Tariffs to Avoid 4 - 7 pm that is relevant.
Thanks @Nomenludi I’ll have a look at that documentation. For me I think it’s hopefully short term problem - at the moment I’ve switched tariff and the import is working but it’s going to take a few weeks to get the export working apparently. So definitely don’t want to be supplying the grid with free electricity!
Once on the export properly I’ll think I’ll just have it charge overnight at cheap rates and then start discharging at 4pm when peak rate kicks in.
I don’t have an AIO but suspect that the software’s the same as for my 3.6 kW Gen 3 inverter.
I suspect that the real issue is that we’ve all been seduced by how well Eco mode works and haven’t recognised that when we set up a charge period or a discharge period, we are, in effect, disabling Eco mode.
I don’t have experience with discharge periods but do have experience with charge periods.
It looks to me as though during a charge period we’re instructing the system to charge the battery at the specified fixed rate. If there’s PV available (i.e. PV exceeds the Load - the first priority for PV is meeting Load), it will use it. If there isn’t enough PV, it will make up the difference from the grid. Once the battery gets to the specified charge level, charging stops. Throughout a charge period (including after the target charge has been reached), the battery is prevented from discharging.
I would expect discharge periods to mean that the battery is discharged at the specified discharge rate until the reserve % is reached, when discharging will stop. Throughout a discharge period, the battery will be prevented from charging.
The great thing about Eco mode is that it adjusts the charge/discharge rate dynamically to match what’s going on, i.e. how much PV is available and what the Load is. When you turn that off, you’re back in an earlier world.
If I could influence GivEnergy’s software development programme, I would ask them to give priority to making charge and discharge periods work more as Eco mode does; in particular
This one change would make an enormous difference. It would allow charge periods to be used during the day to “top-up” the charge to some level from the grid before the start of the 4 - 7 pm period of premium pricing. You can define a charge period from, say, 2 - 4 pm now but if you do so, once 2 pm is reached, the system will charge at the specified rate from PV + grid until the battery reaches the target charge and then disable all further charging. That’s not what I want.
Let’s suppose you want to have 50% charge at 4 pm. Then you would define a charge period from 2 - 4 pm and specify the target AC charge level as 50%. If the battery is already charged to 40% at 2 pm, it would charge using a mix of PV and grid until the charge reaches 50%. It would then stop taking electricity from the grid (because the 50% AC target has been reached) but would continue taking surplus PV which isn’t being consumed as Load.
In your case I suspect you’re aiming for 100% charge at 4 pm. You will presumably charge up as much as you can in the overnight off-peak period. What you then want to do is to harvest as much PV as you can during the day while hitting peak charge at 4 pm. Let’s suppose that the maximum charge rate to your battery is 25% / hour. Then what I envisage (assuming they’ve changed how charge periods work) is that you would set up the following charge periods:
These periods mimic the charge profile which you need to get the battery from empty to full in the least time. It would mean that you would be charging only from surplus PV between the end of the off-peak period and midday. During that period you would be able to meet Load both from PV direct and from the battery. But once you got beyond midday you would be in a charge period, which would disable discharge. If you had at least 25% charge then, you wouldn’t start charging until you got to 1 pm, when the minimum charge level is raised to 50%. At each hour the charge level rises (but so may your charge level - because you’re continuing to accept surplus PV), so it’s only when the charge level is lower than the threshold that that you start “topping-up” the surplus PV from the grid.
As it’s inefficient to discharge the battery during the period of standard-price electricity during the day only to have to charge it up again using standard-price electricity before 4 pm, I would prohibit such discharge by adding a further charge period from the end of the off-peak period until midday. The target AC charge level during this period would be 0%. DO NOT DO THIS NOW - it has the effect of making the battery Idle: it can neither charge nor discharge. But with my proposed change, it would prohibit the battery from discharging while it would continue to be able to receive surplus PV. So the charge periods would be (assuming that you charge from 1 - 4 am):
Note the difference between this and having a single charge period:
This has the effect of charging the battery up to 100% from the grid starting at 01:00 and ending whenever it gets to 100%. This may well be after 04:00, so some of the charging uses standard-price electricity.
My scheme stops charging from the grid when off-peak pricing ends. Between then and 4 pm, the battery would not discharge. But it would continue to receive charge from surplus PV. It would start charging again from the grid if at any hour between midday and 4 pm the charge level lay below the specified threshold. Once that threshold had been reached, say 20 minutes after the hour, grid charging would stop but charging from surplus PV would continue. So the 100% target charge at 4 pm would be met by a mix of off-peak grid electricity, surplus PV and a top-up of standard-price electricity bought during the early minutes of the hours between midday and 4 pm.
This scheme is consistent with the principles of Eco mode and is well within the capabilities of the hardware. I’m disappointed that it’s not how the system works yet. Let’s hope that GivEnergy management recognise that it would really enhance the capabilities of their system and put some software development resources into it.
I’ve been looking again at your posts. I surmise that what you’ve been doing has been to configure your charge and discharge using the phone App. This has limited capabilities and is a poor front-end to what is really going on, which you can only see by using the Web UI in a browser. If you bring that up and click on the cog when the main panel is displaying the Inverter, you are then shown the Remote Control; alternatively use the URL https:// givenergy.cloud/inverter/[inverterID]/remote-control where [inverterID] is the ID of your inverter.
On the Remote Control you can see all the parameters which you can set. You can also configure up to 10 charge and discharge periods. I haven’t been able to find any documentation of these but can tell you how the phone App works as a front-end:
Battery Charge Settings
Battery Discharge Settings
Note that there isn’t a direct correspondence between the phone App settings and the Remote Control parameters. In particular, Enable Eco Mode is turned Off by setting Consumption Type = Full Export but it only gets turned back On when Discharge Mode is set to Dynamic.
If you look at the Charge 1 Settings, you’ll see that there’s an AC Charge 1 Upper SOC % Limit but this isn’t set by anything on the phone App. Nor is DC Discharge 1 lower SOC % Limit. Instead the phone App only provides a front-end to the global limits on charge and discharge % limits.
It appears to me that the phone App front-end was written when only a single charge period and a single discharge period existed and that the Remote Control app has been extended for 10 charge periods and 10 discharge periods without corresponding changes to the phone App.
As setting some parameters on the phone App causes what I consider unexpected changes to be made to Remote Control parameters (specifically to Enable Eco Mode and Enable AC Charge Upper % Limit) I think it’s better to use only the Remote Control until you’re confident you understand how that works.
I aim to post an explanation of what I think the Remote Control parameters mean and what the consequences are of setting them to particular values. That will take some time.
Meanwhile I would advise being in Eco mode as much as possible (assuming you’ve got PV as well as a battery). Charge and discharge periods have the effect of overriding Eco mode, so I’d aim to be in these only while they are providing a real benefit. That clearly includes charging in off-peak periods (but with a charge limit which doesn’t preclude storing or making use of PV which you expect to generate) and discharging in peak periods, if you want the income.
I’ve now posted my User Guide to the App as Managing the Inverter from the App - General / Everything Else - GivEnergy Community Forum
Thanks, but hold your horses. The system is even more complicated than I had thought.
There are some real surprises, e.g. when you’ve been charging in a Charge Period and the Battery Charge reaches Charge Up To, then provided Battery Charge < AC Charge Upper SOC % Limit, the system stops charging the battery from the grid and switches into an amazing and totally unexpected mode. Load is met from the grid and all the PV is sent to the battery !!!
I think this continues until Battery Charge > Charge Up To, when the Charge Period ceases to be in force. If you’ve been using Eco Mode, the system then reverts to Eco Mode. As Battery Charge can either rise or fall in Eco Mode (depending on whether PV > Load or PV < Load) this can either lead to a sustained rise in Battery Charge for the rest of the Charge Period or to Battery Charge dropping back to equal Charge Up To, when it reverts to Load from the grid; PV to the battery.
Note that Battery Charge means the number which you see on the Dashboard, i.e. it is an integer % which is compared against the integer % values of the limits.
I’ve deferred posting my next instalment until I’m satisfied that I’ve got to the bottom of what’s going on.
A few observations / questions about what you’re trying to do. I suspect you’re aiming to charge up overnight using off-peak electricity and want to hit peak charge at 4 pm. If so,
How do you plan to manage the period between the end of your off-peak period and 4 pm?
I presume you want to harvest PV during the day and store in the battery what you don’t immediately use. Given my greater understanding of what happens in a Charge Period, you may be able to do this by having a Charge Period from 2 am - 4 pm with Charge Up To set to, say 60% with AC Charge 1 Upper SOC % Limit = 100 . Overnight it will charge from the grid to 60% and then switch into Amazing Mode and then Eco Mode. It will then run in this, charging from PV and discharging to meet Load, until 4 pm.
It’s inefficient to discharge from Eco Mode during standard price only to recharge at standard price, so you may want to set Discharge Rate = 0 at some point and reset it to the max at 4 pm (but I wouldn’t do this without automation).
Do you plan to do any standard-price charging from the grid in the run-up to 4 pm?
How do you judge the Charge Up To level of overnight charging?
Hopefully the following covers the points you raise.
I’m on Octopus Flux and my plan was to fully charge the battery overnight at the off-peak cheap price (as well as charge the car), and then kick in using it at 4pm to avoid peak time import. My initial thinking was how to set the overnight charge limit with a view to topping up to full using free PV during the day but I don’t think that’s the right approach as the export rate during the day is marginally greater than the import rate off-peak so there’s a marginal gain during the day in exporting any PV you’re not using over storing it. Key really is to avoid importing from grid during peak pricing 4-7pm.
During peak period I want to export as much battery or PV that I’m not using. The challenge is to not run out of battery before peak ends if there’s likely not enough PV to keep you covered. Not quite sure how to manage this as yet. Exporting to grid and running out of battery after peak period ends again doesn’t really matter because the standard import price is marginally less than what you got for the peak period export.
It looks to me as though during the day
If Load is small, you may not mind. But I would prefer to charge to a lower level overnight and aim to top up from surplus PV during the day, supplementing if necessary with a boost from the grid in the run-up to 4 pm.
Also, don’t ignore the losses associated with charging and discharging. They are a real cost.
Here’s what I think is going on in Charge Periods:
When a Charge Period is in force, the battery is prevented from discharging. By default, all the upper SOC % limits on individual Charge Periods are set to 100.
For now, we’ll assume that this applies.
This means that, while Battery Charge < Charge Up To, the battery charges at Charge Rate:
When Battery Charge reaches Charge Up To, if it’s night and there’s no PV:
If, however, the Charge Period is during the day and there is PV, the system enters a special PV-Charge Mode in which:
This continues until either:
PV-Charge Mode is similar to bump-starting a car: it is a mechanism which provides
a small impetus to get the system moving again. In this case it is to cause the Charge Period to lose force so that Eco Mode can come into force. When that happens, the Battery Charge can rise or fall according to whether PV > Load or PV < Load.
PV-Charge Mode therefore allows a Charge Period to extend from an overnight off-peak period into the day. Charge Up To can be set at a level below 100 to which you wish to charge from the grid. Once the Charge Period comes into force, the battery is charged at Charge Rate from the grid until Charge Up To is reached. Charging then ceases. Load is met from the grid.
Day breaks and PV starts. It flows into the battery. Initially the % Battery Charge remains unchanged and the Charge Period remains in force. But as the sun rises and more PV is generated, eventually the % Battery Charge rises above Charge Up To. Now the Charge Period ceases to be in force and is superseded by Eco Mode.
If PV > Load, the system will now remain in Eco Mode, with Load being met from PV and the surplus PV being stored in the battery. This continues until the end of the Charge Period.
If PV < Load, the system will remain in Eco Mode until Battery Charge = Charge Up To. It will then revert to PV-Charge Mode. So, as the relationship between PV and Load fluctuates, the system will oscillate between Eco and PV-Charge Modes with Battery Charge either equal to Charge Up To or 1 above.
By the end of the Charge Period, the % Battery Charge will either be Charge Up To or the system will have managed to escape into Eco Mode and surplus PV will have raised % Battery Charge above Charge Up To.
Further testing has led me to revise my views on this:
When a Charge Period is in force, the battery is prevented from discharging. By default, all the Upper SOC % Limits on individual Charge Periods are set to 100. For now, we’ll assume that this applies.
This means that, while Battery Charge < Charge Up To, the system works in Charge Rate mode:
This continues until either:
When Battery Charge reaches Charge Up To, the system switches to Grid = Load mode:
Note that:
In some circumstances (which I haven’t yet been able to characterise), it appears that the increase in Battery Charge can cause the Charge Period to cease to be in force before the end of the Charge Period; otherwise the system remains in Grid = Load mode until the end of the Charge Period.
If the Upper SOC % Limit for a Charge Period < 100, we have to consider Battery Charge’s relationship with it as well as with Charge Up To. It turns out that there is a third mode which the system can be in while a Charge Period is in force: Battery Idle mode. This is similar to Grid = Load mode in that there is no charging from the grid. It differs from it in that the usual priorities apply:
It turns out that the modes apply as follows:
if Battery Charge < Upper SOC % Limit:
if Battery Charge ≥ Upper SOC % Limit:
Recall also that:
I’m coming to the view that the behaviour of the inverter at any time doesn’t just depend on the current values of parameters but also on the Mode the inverter was working in when a parameter changed.
Such a system is what is known mathematically as a Finite-State Machine. To describe such a system you need to define the states (for the inverter, the Modes: Eco; Charge Rate; Grid = Load; Battery Idle; etc) and the transitions (i.e. what the conditions are which cause it to switch from one state to another.
We’ve already seen that if at the start of a Charge Period, Battery Charge > Charge Up To, the system doesn’t switch out of its current Mode (e.g. Eco Mode). Nor, at the start of a Charge Period does it change its state if Battery Charge = Charge Up To: if it’s in Eco Mode it remains in Eco Mode. We shall assume for now that PV = Load while we are in the Charge Period so that Load is met from PV and Battery Charge remains constant.
But if at the start of the Charge Period, Battery Charge < Charge Up To, it switches to Charge Rate Mode. If subsequently within the Charge Period, Battery Charge = Charge Up To, it switches into Grid = Load Mode.
So here we have identical conditions: Battery Charge = Charge Up To in a Charge Period but the system is in Eco Mode if Battery Charge has remained constant at Charge Up To from before the start of the Charge Period. If, however, at the start of the Charge Period, Battery Charge was less than Charge Up To, the system is in Grid = Load Mode.
As it appears that the inverter is a Finite-State Machine, it will take longer to characterise its behaviour. Meanwhile, here’s a list of states:
Eco Mode
Charge Rate Mode:
Grid = Load Mode:
Battery Idle Mode
Discharge Rate Mode
Note that I haven’t used Discharge Rate Mode, so its behaviour is a guess; please report if it’s wrong. Other comments and corrections would be welcome.
I’d also welcome people’s observations on how Charge Rate and Discharge Rate are applied. The impression I’ve got is that Charge Rate is applied accurately when charging from the grid during a Charge Period but that when the system isn’t in Charge Rate Mode, (so it’s only PV which is being stored) the limit which is actually applied is about 1.3 * Charge Rate.
I’ve posted more about Octopus Flux at Discharge Algorithm for Octopus Flux on Battery Management with Octopus Smart Tariffs to Avoid 4 - 7 pm
This is a great post but one thing is left out from your Eco mode description. When does Eco mode charge the battery from AC back to full again? Will this happen during the night? If so what hours or is this dynamic based on Grid load. Trying to work this out as I don’t want my battery to start charging during the day when the price is high if I go Eco mode only and disable the charge and discharge periods
I believe the discharge mode is broken, or some GivEnergy engineers and support are confused about how it works. Previously, GivEnergy support acknowledged to me that scheduled discharge was broken, but in my last contact with support they struggled to understand the problem, and then just ignored my questions.
In the App, there is “timed discharge” and “timed export”
In reality, these modes seem to have exactly the same behaviour.
GivEnergy support (James Lewis) told me "For the scheduled discharge meeting home demand rather than discharging to meet home demand would mean introducing an AI into our batteries which we currently do not have. " I’m not sure why the battery (not inverter) would need “AI” to do something the inverter already does (Eco mode), but just scheduled.
What confirms to me that this feature is just not working correctly is that the smart tariff uses it, and in doing so will immediately discharge the battery at full power right after charging it – leaving you without battery charge when you need it during the peak period. As such, the smart tariffs don’t work.
It would be great if a GivEnergy engineer could set the record straight here, as this has been an issue since I got my inverter a year ago.
Might I suggest that, unless you are actively beta-testing some product, you join us on the regular community.givenergy.cloud rather than this beta one - there’s a lot more of us on there.
Almost. Timed-export turns the eco flag off, whereas timed-discharge leaves it on. So (except on some gen-1 inverters) they behave the same within the timed window, but behave differently outside the timed window (with timed-discharge being a lot more useful).