Growatt battery not discharging

[johnb2713]

Try turning it round the other way. If it's on the wrong way round it will never try to support your grid supply because it wont see it as import, all it will see is export so it's quite happy to do nothing.

 

[thfctom]

Tried that, switched it round (I assume you mean like this):



I waited 5 minutes, turned on the hob to take the load above what PV was supplying, and as you can see from smart meter and app screenshot, we're importing energy and not using battery still.

Thanks for your help so far! Hope we get to the bottom of this.

 

[johnb2713]

Tried that, switched it round (I assume you mean like this):

View attachment 15655

I waited 5 minutes, turned on the hob to take the load above what PV was supplying, and as you can see from smart meter and app screenshot, we're importing energy and not using battery still.

Thanks for your help so far! Hope we get to the bottom of this.

Turning round so that the left hand face is then at the right hand side. The Growatt CT's should have an arrow on them either on the outside or in the bore where the cable goes through, this should point away from you meter and towards your consumer unit.

 

[user 36882]

Scratch that, battery is still not discharging and I’m still importing energy from the grid at night or during the rain this morning.

Very annoying. I have a case open with the installer but I don’t have much hope, based on your dealings with your installer @milomonster. Out of interest, who was your installer?

We used an MCS/recommended installed in Scotland (where we are located) - did the three comparative quotes, chose them and they did their work exactly when and as they said, but finally fessed up was first Growatt installation they'd done when we started having issues. I've been really patient with them, but after six months they really need to be making some systematic investigation to resolve the issues, not just some random suggestion of 'try this' and see what happens.

 

[thfctom]

Turning round so that the left hand face is then at the right hand side. The Growatt CT's should have an arrow on them either on the outside or in the bore where the cable goes through, this should point away from you meter and towards your consumer unit.

Found the arrow and clamped it on in the direction required (which was the originally installed direction).

Still no change to the battery status sadly, I'm still importing from the grid when the panels aren't generating enough.

 

[johnb2713]

Found the arrow and clamped it on in the direction required (which was the originally installed direction).

Still no change to the battery status sadly, I'm still importing from the grid when the panels aren't generating enough.

It sounds like it isnt seeing the CT or the CT is faulty.

 

[thfctom]

Just had a thought. The load consumption is always matching (or 0.1kW less than) the PPV, no matter how much energy the house is using:



If the system thinks the house load consumption is the same as or less than the PPV, it will assume the battery isn't required.

Therefore the route cause is the system not knowing what the actual load consumption of the house is. Is this the job of the CT?

If I unclip the CT from the live cable, a small hum/buzz stops. When I reclip the CT to the cable, the hum/buzz resumes. Does this mean the CT is at least doing something?

 

[johnb2713]

Just had a thought. The load consumption is always matching (or 0.1kW less than) the PPV, no matter how much energy the house is using:

View attachment 15658

If the system thinks the house load consumption is the same as or less than the PPV, it will assume the battery isn't required.

If the battery is full in the above condition it should start exporting to the grid assuming the export limit isnt set.

Therefore the route cause is the system not knowing what the actual load consumption of the house is. Is this the job of the CT?

If the inverter sees import happening via the CT it should increase it's output voltage until either it's max output is reached or the import stops. Conversely, if it sees, export taking place and it's battery isnt full it will increase the charge current to the battery by reducing it's output voltage.

If I unclip the CT from the live cable, a small hum/buzz stops. When I reclip the CT to the cable, the hum/buzz resumes. Does this mean the CT is at least doing something?

It sounds as if it is but something isnt right in this system somewhere

 

[thfctom]

Weirdly, as you can see from the app screenshot, the battery actually kicked in earlier, and I thought all was well. Then it stopped and we were drawing from the grid when the solar generation stopped for the day.

From the other screenshot, you can see I raised this with them, and you’re somewhat vindicated - they’re also claiming CT issue, although they’re not being very helpful with their responses. Other than unclamping it and clamping it back on, is there anything else I can do to “reinstall it” without getting the installers back out?

Finally, my EV charger has kicked in tonight, as it’s cheap energy time. The CT clamp is making a huge rattle/buzzing sound. If I unclamp it, the buzzing stops. If I reclamp, it starts again. If I stop the charger, the buzzing stops, and then starts again if I restart the charger. The noise isn’t an issue as the meter is downstairs, but it doesn’t sound healthy! Could this be an issue that needs addressing?

 

[johnb2713]

Weirdly, as you can see from the app screenshot, the battery actually kicked in earlier, and I thought all was well. Then it stopped and we were drawing from the grid when the solar generation stopped for the day.

From the other screenshot, you can see I raised this with them, and you’re somewhat vindicated - they’re also claiming CT issue, although they’re not being very helpful with their responses. Other than unclamping it and clamping it back on, is there anything else I can do to “reinstall it” without getting the installers back out?

Finally, my EV charger has kicked in tonight, as it’s cheap energy time. The CT clamp is making a huge rattle/buzzing sound. If I unclamp it, the buzzing stops. If I reclamp, it starts again. If I stop the charger, the buzzing stops, and then starts again if I restart the charger. The noise isn’t an issue as the meter is downstairs, but it doesn’t sound healthy! Could this be an issue that needs addressing?

That really doesnt look right and from what youve said it seems like a CT / Inverter issue, maybe the wrong CT?

I think you need to get the installer back.

 

[thfctom]

Ok it’s just got even weirder. The battery decided to drain itself this morning, down to 10%.

There’s no way the house was using that much, it must’ve just exported that energy to the grid.

It should now be charging as we’re not using anywhere near what the panels are generating.

As you say, definitely needs looking at!

 

[thfctom]

I haven't changed any settings, and it's now on grid-first mode. It should never be in this mode. Priority should be: Load, then battery, then grid. If the time is between 00:10-05:20, it's battery first, potentially with AC charging. If not, it should always be load. The battery should be charging at this point.

 

[stuboy]

If your CT is making lots of noise it is either:- A) Not closed properly B) Not got a load on it, i.e. its not plugged in! Can you confirm on your inverter that it is seeing the CT and responding to it? Is it direct or via mod bus on those?
Cheers
Stu

 

[thfctom]

How do I see on the inverter if it's seeing the CT?

I think it's direct, see image here:

Yeh I believe so. It’s clipped to the live wire here.

 

[johnb2713]

I haven't changed any settings, and it's now on grid-first mode. It should never be in this mode. Priority should be: Load, then battery, then grid. If the time is between 00:10-05:20, it's battery first, potentially with AC charging. If not, it should always be load. The battery should be charging at this point.

It should be on load first

 

[bladerunnerpv]

Hi, just following this thread out of curiosity, I know now't here, but ...

I had a look at the SPH3000-6000 Quick guide to compare against your IMG_3745.

Where it says "two holes", there are two red cables and two black cables, presumably from battery, entering it.

There is also a grey cable nearby, does that grey cable also enter the "two holes" grommet? (is grommet the right word?) I can't tell from the img.

In IMG_3745 where it says "six holes", is that black cable the CT input?

hope this helps rather than hinders, best of luck

 

[shaunuk]

Ill put £10 on the Electric Car draining the battery over night because the inverter is not transitioning into battery first mode during the charging period.

Set battery first schedule to be the same as the car period. Also check CT is plugged into the correct port on the inverter and facing the correct way, the arrow should be facing the load, so pointing away from the Meter.

You will know if its working because your smart meter in home display will show 0 (or within 50 watts of 0) when the kettle is on.

Your welcome

 

[thfctom]

Hi, just following this thread out of curiosity, I know now't here, but ...

I had a look at the SPH3000-6000 Quick guide to compare against your IMG_3745.

Where it says "two holes", there are two red cables and two black cables, presumably from battery, entering it.

There is also a grey cable nearby, does that grey cable also enter the "two holes" grommet? (is grommet the right word?) I can't tell from the img.

In IMG_3745 where it says "six holes", is that black cable the CT input?

hope this helps rather than hinders, best of luck

Hi, thanks for the input.

Yes, "two holes" has two red and two black cables, both from battery entering it.

Grey flat cable (1) has bypasses inverter - not sure where that goes. Round grey cable (2) enters the "six holes" input. This round grey cable goes to the CT I believe - it definitely goes in that direction and connects to a black cable which I'm pretty sure is the one that leads to the CT near the meter.



The black cable from "six holes" goes to the "PCS" input on one of the batteries.

 

[thfctom]

Ill put £10 on the Electric Car draining the battery over night because the inverter is not transitioning into battery first mode during the charging period.

Set battery first schedule to be the same as the car period. Also check CT is plugged into the correct port on the inverter and facing the correct way, the arrow should be facing the load, so pointing away from the Meter.

You will know if its working because your smart meter in home display will show 0 (or within 50 watts of 0) when the kettle is on.

Your welcome

The EV charger was not on when the battery was draining. This is timed to stop at 5:30am, the screenshot below shows it kicking in after 5:45.



By battery first schedule, do you mean the time it AC charges? If so, the battery first schedule is pretty much same as car period (car is 23:30-05:30, battery is 00:10-05:20).

CT is plugged into "six holes" port on inverter. Arrow is pointing away from meter.

 

[johnb2713]

Looking at post #32, you need to be on load first, your inverter is exporting everything generated to the grid.