Battery drain

[iOddJobBob]

To test the theory, I changed the work mode from 8pm to 8:45pm and as expected, the spike came at 8:45pm. Here’s the “real-time” from solarman during and after. I’ve also posted the stats from the inverter at the time, I’m not sure if it helps?

[JayMardern]

My gut says we shouldn’t be seeing a negative value for CT1 (-886W) as this might indicate a reversed CT causing unwanted selling to grid.

 

Can anyone with 3-phase experience confirm the above?

[PowerUser]

@iOddJobBob what’s the firmware version on the inverter?

[Scorp007]

24 minutes ago, iOddJobBob said:

To test the theory, I changed the work mode from 8pm to 8:45pm and as expected, the spike came at 8:45pm. Here’s the “real-time” from solarman during and after. I’ve also posted the stats from the inverter at the time, I’m not sure if it helps?

L1 power reading shows negative 886W which seems like a CT direction wrong. 

Further if L2 draws 10A then the power could not be only 566W.

What happens if you switch the grid off just before the timer change. 

Edited August 3, 2023 by Scorp007

[PowerUser]

2 minutes ago, Scorp007 said:

L1 power reading shows negative 886W which seems like a CT direction wrong. 

What happens if you switch the grid off just before the timer change. 

Yes, that reading looks odd. @iOddJobBob is it possible to check the directions on the arrows on the CT coils and the way they are connected in inverter?

[Scorp007]

17 minutes ago, PowerUser said:

Yes, that reading looks odd. @iOddJobBob is it possible to check the directions on the arrows on the CT coils and the way they are connected in inverter?

Without checking the CT2 just reverse the 2 wires in the inverter. 

[iOddJobBob]

@Scorp007 if I switch off mains while the drain is happening, it stops and functions normally. 
 

@PowerUser firmware is ver2005-1128-1807

excuse my ignorance, but which ones are the CT coils?

[Scorp007]

40 minutes ago, iOddJobBob said:

@Scorp007 if I switch off mains while the drain is happening, it stops and functions normally. 
 

@PowerUser firmware is ver2005-1128-1807

excuse my ignorance, but which ones are the CT coils?

[iOddJobBob]

2 minutes ago, Scorp007 said:

Thanks. This helps. I’ll have a look when home this evening 

[JayMardern]

5 hours ago, iOddJobBob said:

Thanks. This helps. I’ll have a look when home this evening 

 

5 hours ago, Scorp007 said:

 

Is our problem not CT1 (since that's where we're seeing the big negative in the Solarman screenshots)? Or do the small trickle-sized negatives on the inverter display indicate a problem with that coil, i.e. CT2 instead? I run single-phase so I'm not entirely sure myself; just asking to be safe.

 

It looks like we've found our phantom load!!!

Edited August 4, 2023 by JayMardern

[iOddJobBob]

1 hour ago, JayMardern said:

 

 

Is our problem not CT1 (since that's where we're seeing the big negative in the Solarman screenshots)? Or do the small trickle-sized negatives on the inverter display indicate a problem with that coil, i.e. CT2 instead? I run single-phase so I'm not entirely sure myself; just asking to be safe.

 

It looks like we've found our phantom load!!!

I'm a complete noob here, so will take advice from the experts

[iOddJobBob]

I opened the DB and can’t tell which direction the CT coils are going and don’t feel comfortable enough to start fiddling around. 
 

opening the inverter though is easy enough. Should I be looking at changing the wires for CT1 or CT2?

[abd7]

It's CT 1 that needs to be changed around

[iOddJobBob]

19 minutes ago, abd7 said:

It's CT 1 that needs to be changed around

 

[iOddJobBob]

41 minutes ago, iOddJobBob said:

 

The CT1 cable in pin 4 was loose. Could that have an impact?

[Scorp007]

6 minutes ago, iOddJobBob said:

The CT1 cable in pin 4 was loose. Could that have an impact?

We did point out there was a strange reading on ph1 as well as ph2. 

See how it goes. 

[gimme_power]

On 2023/08/02 at 8:55 PM, iOddJobBob said:

The confusing bit for me is the massive drain that correlates with the change in work mode times and then the subsequent stabilisation at much lower consumption. Shouldn’t the discharge be more gradual?

The SOC overlay shows an immediate drop - within minutes - from 55 to 40 at 6am and similarly the drop to 70 at 8pm. If I were to change to time of use to any other time, the same pattern is observed. 
 

I’ve got 2 Hubble 5.5Kw batteries 

I want to offer another possible explanation.  Please check the SOC on the batteries individually. My experience is that if the one pack has a different SOC than the other one, the master battery will report the highest SOC to the inverter when charging, and when discharging, it will report the lowest SOC of the packs (This is a PACE BMS, so not sure what the Hubble does). So if its stable for long when maintaining e.g. 70% (highest of the two batteries) and it suddenly starts discharging then drops to e.g.60%, which is the SOC of the other battery. I also notice it when charging.

If this is the case you need to investigate why the one battery loses charge faster.  Mine is not quite as dramatic, but I notice 3-5% drop sometimes.

 

Edited August 5, 2023 by gimme_power

[iOddJobBob]

26 minutes ago, Scorp007 said:

We did point out there was a strange reading on ph1 as well as ph2. 

See how it goes. 

Will try and see how it goes. Otherwise I’ll be calling the installer. There’s only so much I’m willing to experiment

[JayMardern]

6 hours ago, gimme_power said:

I want to offer another possible explanation.  Please check the SOC on the batteries individually. My experience is that if the one pack has a different SOC than the other one, the master battery will report the highest SOC to the inverter when charging, and when discharging, it will report the lowest SOC of the packs (This is a PACE BMS, so not sure what the Hubble does). So if its stable for long when maintaining e.g. 70% (highest of the two batteries) and it suddenly starts discharging then drops to e.g.60%, which is the SOC of the other battery. I also notice it when charging.

If this is the case you need to investigate why the one battery loses charge faster.  Mine is not quite as dramatic, but I notice 3-5% drop sometimes.

 

In this case we’re seeing quite big negative CT readings (nearly 1kW); it definitely looks like an unwanted export to grid. The Sunsynk manual describes this as a sign that a CT is reversed.

 

6 hours ago, iOddJobBob said:

Will try and see how it goes. Otherwise I’ll be calling the installer. There’s only so much I’m willing to experiment

Yeah regardless of anything else, this is an installation or (less likely) hardware issue; if you don’t come right call in the cavalry. Let us know what happens once you’re sorted!

[gimme_power]

1 hour ago, JayMardern said:

In this case we’re seeing quite big negative CT readings (nearly 1kW); it definitely looks like an unwanted export to grid. The Sunsynk manual describes this as a sign that a CT is reversed.

1000W draw for a short time is not enough to reduce SOC by 10%-15%. What is the duration of those spikes of unwanted export to the grid? 

[iOddJobBob]

Just now, gimme_power said:

1000W draw for a short time is not enough to reduce SOC by 10%-15%. What is the duration of those spikes of unwanted export to the grid? 

About 10 minutes. As long as it takes to get to new SOC

[gimme_power]

1000W for 10mins equals 3% SOC of one 100Ah battery, so not quite going to get to a 10% drop in SOC of the combined bank. 

 

Have you checked the individual SOC of the two batteries, do they differ and by how much? 

Or are we talking about a 10kW draw? 

Edited August 5, 2023 by gimme_power

[JayMardern]

On 2023/08/02 at 9:45 AM, iOddJobBob said:

I’ve recently installed solar and have noticed that every time the work mode changes, the battery has a rapid drain to move down to the relevant setting, e.g. from 21h00 to 00h00 battery is set to 70% and then from 00h00 to 06h00 battery is set to 40% and at 00h00 it has rapid drain from 70% to 40% and then stabilises. This pattern happens every time the battery setting is lower than what current SOC is when shifting to new work mode. Is this normal or is something set incorrectly?

@iOddJobBob did you sort this out? Were we right about grid export or was it something else!