Timed Export Question

I’m trying to configure an evening export window so I can push excess stored energy back to the grid, then recharge during the off‑peak period starting at 00:30.

My setup was:
• Export window: 21:00 onward
• “Export to” threshold: 15%

My assumption was that the system would export down to 15%, then continue discharging normally to supply the house.
Instead, once the battery reached 15%, it stopped discharging entirely and the house load moved to the grid.

It looks like I’ve misunderstood how the threshold logic works.
Is the behaviour I want (export down to X%, then continue discharging for self‑consumption) actually possible?

Any insight would be very welcome.

Smurfy Is the behaviour I want (export down to X%, then continue discharging for self‑consumption) actually possible?

Not with the built-in firmware, AFAIK. Generally have to rely on external software to manage this. Either keep an eye on the level, and stop the discharge when it is reached, or calculate the starting time or discharge power so that it arrives at the level you want at the correct time.

Smurfy this is a common misunderstanding

Think of it this way:

You set the inverter to export mode from 21:00 to 23:00

You set a limit on the battery SoC to 15%

So when the battery reaches that SoC limit it will stop discharging the battery (you set a hard lower limit), but since it is in export mode until 23:00 it remains in that mode and any house load has to come from grid import.

This is probably not what you want but is the way it works. If you want to stop the grid import at the end you need to vary the start time of the discharge, the discharge rate or the lower SoC limit so the inverter doesn't reach the lower limit before the end of the time period.

That’s a real shame. Maybe it’s something they will add in the future.
Thanks for your replies.

Yeah, unfortunately it doesn’t work quite like it should to achieve what you’d like.

But a good work around is this;

Just start your “timed export” later, so it finishes at ₄% (or whatever % you want) at 0030. And then you can set up a “timed charge” to refill the battery immediately after that at 0031 onwards during the off peak rate.

That way you’ll use the battery to supply the house in the early/ late evening and have the latter part of the evening when it’s exporting (and also using the battery to supply the home). So doing this you shouldn’t use any unnecessary peak rate, assuming you set the export start time correctly. What happens is basically the battery discharges at max rate and what is exported to the grid is that rate minus what the home is using during that period including any spikes in usage.

So the actual export to the grid varies depending on what is going to the home but the battery is always depleting at the same rate. It’s supplying your home and exporting what’s over that to the grid.

You’ll need to work out when to set the start time of the “timed export” and modify it a bit in summer and winter (not much during summer as the batteries are probably quite full) but that should achieve what you want it to, just differently. Assuming you goal is to maximise your export revenue and use no (or minimal) grid at peak price and not run out of battery before the cheap rate starts.

For me, my batteries discharge down during a “timed export” at a rate of about 20% per hour.

So, for example if you have 45% left in your battery at 2230, set the timed export to start at 2230–>0030. And you’ll have the battery down to about 5% at 0030, ready for a refill.

If you had 85% left at 20:30: start the timed export at 2030–>0030. Etc…

Modify as required. But always have the same end time at 0030 !

In the summer it’s easy, I don’t have to change the start time of my timed export (it’s 19:00–23:30; I’m on IOG, so for me it’s 23:30 not 00:30), but when solar generation drops off in the winter I gradually push the timed export start time back by 15 mins or so each week if required (I actually check on a daily basis for
more precision). Last few days it’s been 20:45–>23:30, as I’ve been at about 60% at 20:45.

The percentage your battery depletes at during a timed export may be different to mine depending on your kit but you get the idea.

Hope that’s useful.

Pete UK thanks Pete

Thankyou Pete UK, I was also looking for an answer to this very question having installed a 2nd battery to my system at the end of January so I could reap the rewards of Octopus Flux and encountered this frustrating procedure. Have you also noticed that the Timed charge period has exactly the same error although its not so bad as you are in the cheapest grid cost? Surely 100% of all GE users would prefer the method Smurfy has described with the system immediately reverting to battery to home when the chosen Charge / Discharge level is achieved.
How do we kick start GE to give us that change?

Mickyboy How do we kick start GE to give us that change?

its the way the firmware is coded. I doubt very much we could get it changed, but no harm in asking of course

givenergy support email address is on the website

Mickyboy Surely 100% of all GE users would prefer the method Smurfy has described with the system immediately reverting to battery to home when the chosen Charge / Discharge level is achieved.

In a word - No. If I have cheap energy between 1300-1600hrs I do not want to be wasting charge that could otherwise see me through the very expensive period 1600-1900hrs or even the daytime pricing between 1900-2200hrs. Why pay more than twice as much for energy later on.
For EV tariff users the period between cheap rates is double digit hours and most presumably expect to run out at some point in the afternoon or evening leaving hours at daytime rates.
Cutting their stored charge by using even half an hour from the battery during cheap rates makes no financial sense at all for most.
If you have X hours at cheap rates and Y hours until the next cheap time what probably makes most sense financially is to charge slower than the maximum rate so the charge finishes just a few minutes before the cheap period ends and then hold that charge (i.e. just run off the grid) until the tariff rate changes. This will also reduce the wear on the battery and the charging losses.
GivEnergy don't offer any native "full by" functionality, but this can be achieved with third party scheduling tools like PredBat.
If you want to charge as quickly as possible and then run from the batteries immediately, accepting higher wear and losses, then it is probably possible to achieve that with third party tools as well.

With reference to discharge it is definitely possible to use tools like PredBat to manage your discharge rate so that it doesn't predict that you will run out/pass below at set State of Charge before your next cheap period and it can dynamically update this as variations in your usage leave more or less battery available.
It is worth remembering that some users will wish to retain some percentage of their battery for backup purposes in the event of a power cut and would this see minimum limits as a hard floor.
TLDR Get PredBat.

It seems that we all want this! but givenergy can't be bothered changing a couple of lines of code to do This!

pwdst my cheap rate starts at 12:30, so I’m planning to export around 22:30. With a reserve set so the battery never drains to empty, that reserve leaves me just enough to get me through to 12:30. By the time 12:30 rolls around, the battery is almost empty, so I can charge it back up at the cheapest rate.