Windy Cloudy day causing chaos

Hi all,

We're having a particularly windy day down here, with broken clouds, often spurts of high solar as the sun peaks out.

I'm seeing weird behaviour:

• The system is exporting to the grid despite battery only at 75%, sporadicly
• My solar iBoost has taken over, assuming there is exporting going on, heating the immersion
• Battery then starts to feed the iBoost

Like a runaway train... I've turned the iBoost off at the spur so that the battery will charge at least... but it seems the cause of this is the fluctuating amount of sun leading the battery to stop charging and cause more exporting?

pacemaker Just out of interest, what is the IBoost Storage Offset set to?

SilverArt its set to 300w at the moment.

pacemaker at the moment.

just to be clear are you saying it is set to 300w or is using 300w at the moment.?

positor1

Its set to 300w, it was using 2kWh before I turned it off.

The problem is, the battery is charging at lets say 500w, when the sun comes out the battery can't react it seems quick enough when it jumps to say 3kW/4kW of production, so it seems to pause charging, and then it all goes to the grid.

During the period where the battery is "paused"/"thinking" iBoost takes over as it sees 1-2kW going to the grid. It's basically quicker than the battery at responding. Once iBoost has started then its impossible to stop as battery then thinks there is more house power needs, and discharges...

Edit - it might not be the sun coming out that causes the battery to "pause", it maybe a spike in house demand - but either way the changeable conditions seem to be creating the chaos - as its fine on other days.

is there a time delay that you can set on i boost like you can on the Eddi?

positor1

Nope.

Here you can see today, where its exporting instead of charging (as of right now battery is 85%)

Here is the export isolated:

Here is the export for the previous day when battery was not charged either. Vary rare spikes, as it charged the battery as expected.

I am shocked there is not a delay time setting. perhaps if there is an iboost forum there will be an answer?
Turning the iboost off for 5 mins should allow the battery to take the charge again but you cant keep doing that each time the sun comes through a cloud. I am at a loss sorry. can you return it and get an eddi? it doesn't sound fit for purpose.
i don't suppose your battery is set to charge at a low rate is it?

positor1

i don't suppose your battery is set to charge at a low rate is it?

No, its set to defaults

Take the iBoost out of the equation for a second though, if we just focus on battery and export, what's going on?

The iBoost doesn't help with its lack of functionality that's for sure... but is it expected that the battery stops and starts charging, leading to more export, despite not being charged during days like today?

I have an iBoost + changable weather here also, and I also have someone sanding some wooden floors right now, which is causing some very rapidly changing load. At one point it seemed like my inverter/battery just gave up trying to understand what was going on, and stopped supplying or charging for about 5-10 minutes... which seemed fairly baffling.

pacemaker Take a look at your smart meter and check exactly how much is being exported. The graphs you posted show very transitory peaks of export. This is normal to see if the sun keeps going in and out. The inverter takes time to react and ramp up charging. During this time excess over load will go to grid - but it's for a very short time. The graphs are plotted in line with polling which is 5 minutes data points. It does not average - just lots of tiny points in time - each one of which can be misleading. If you use the app and watch closely you should see the peaks are short as the app polls (in local mode) every 10 seconds.

pacemaker All I can say is that I don't see spikes that big,, or looking at your previous day, quite as many that size.
Could it be an electrical 'noise' problem somewhere?

cluelesscris

Yeah understood. I am watching the 10 second intervals... for long periods it was exporting to grid, 45-60 seconds, until the battery would start charging again. its not crazy amounts - about 1kW today, but that lag is where the iBoost takes advantage of "excess going to grid" and jumps in the way.

SilverArt

its not usually like it. On a day with consistent sun (or no sun) there are no spikes, it exports (or not) to grid in a predictable, smooth way. It only seems to be days where the solar production is spiking that this behaviour is seen for me.

I see the same behaviour on days when the cloud cover is very variable: anecdotally this is like the inverter/battery combination just gets breathless and can't deal with any more changes! On a few occasions I've placed the system into charge at maximum rate and reverted to 'Play' in around 20 seconds and it sorts it out, returning to normal operation.
I have an Eddi but haven't had enough time or solar to look further other than learning that the Eddi beats the Givenergy kit in a footrace to export.
The point about power spikes being different to actual energy exported is a very valid one (this has also fooled me with the Myenergi app which does the same misleading act).

The faster reaction of the new firmware is good. I can now confidently leave by iBoost on and not worry about thermal runaway.
It does grab some power, then the tick tock happens and the iBoost dies away in a few seconds.

The Inverter exports so much less, the iBoost just cant react fast enough to grab it. Unless a particular large spike, then it does for a few seconds, then winds down with each refresh

TheDragon (GivEnergy)

That's good news then. Finally it might work without me worrying its taken over!

I found the iboost was taking solar rather than charging the battery on days when the sun went in and out - not for long - but just long enough to be annoying. So as I'm at home I switch it off until battery is at 100% and then turn it back on. On sunny days I just leave it alone. Just as an aside - if you want o export to the grid - turn the iboost off first as when the timed export starts the iboost steals the first part of the export because it is seen as house load.

Karen

Yeah just had to do exactly the same now, it started to take over and battery wasn't charging. Will turn it on later.