Solax Inverter Hanging onto grid: Query

[Mach13]

My kit: 4Kw panels, Solax X1 5T Hybrid 5KW Inverter and 2 x Solax 5.6KW batteries. With an iBoost for heating hot water with excess energy.

Generally working absolutely fine... Apps really useful, tho doesn't seem to show particularly accurate data.. tho i'm not too fussed about that.

I'm charging the batteries overnight and the solar tops things up during the day. so daytime (peak rate) grid draw is next to zero

One thing I'm bemused about if anyone has any experience of Solax Inverters

When the batteries are set to charge between 12:30 and 4:30 obviously the inverter draws from the grid until the charge period is released.. At 4:30am id expect the batteries to take up power delivery.. Which they do for the main part..

BUT I've noticed that whenever the home power draw is less than around 100watts the inverter allows this to come from the grid.. this is usually until we get up and start drawing more power (kettle etc..) at which the draws goes to battery... NB I'm not talking about intermittent grid draws.. i'm talking draws that can last for hours- albeit of around 70-80 watts .

Is this just just one of those anomalous things that inverter systems do.. or is there a setting somewhere that will resolve it so that it always draws from the battery no matter how small the draw is?
Thoughts welcome

 

[+Sid]

I can imagine that this is really annoying. It seems strange that 'power consumption' doesn't seem to be mentioned in inverter specs like in most other electrical devices, unless I'm missing something. From what I've read on this forum a power draw of a few watts is normal.

 

[Jedw]

I can imagine that this is really annoying. It seems strange that 'power consumption' doesn't seem to be mentioned in inverter specs like in most other electrical devices, unless I'm missing something. From what I've read on this forum a power draw of a few watts is normal.

I have a 6Kw Solis hybrid, export limit set ON and set to zero which is important, generally import and export during peak is about 200Wh per day and from what I can see is unavoidable, if you are on a grid head which is shared with a lot of users I think the grid is noisy from lots of large load on and removal events ( e.g. electric kettles popping on and off) and general grid potential arbitration by the hybrid generator.

 

[bladerunnerpv]

Hi Mach13,
from reading other threads it might be worth taking a look at the inverter minimum state of charge (SoC) settings for the battery and your battery charge level when this occurs.

What you're seeing might be an effect of the inverter managing the battery. As the battery discharges, if the charge level drops down to the SoC threshold then the inverter will switch from battery and start to draw from the grid to prevent discharge below this level. The SoC threshold can be in the region of 20%.

I'm assuming there's insufficient PV for the load demanded and so the battery would be supplying if it could.

[edited from this thread : https://electricianforum.co.uk/thre...-new-pv-installation.55104/page-3#post-531830]

hope this helps

 

[Mach13]

Hi Mach13,
from reading other threads it might be worth taking a look at the inverter minimum state of charge (SoC) settings for the battery and your battery charge level when this occurs.

What you're seeing might be an effect of the inverter managing the battery. As the battery discharges, if the charge level drops down to the SoC threshold then the inverter will switch from battery and start to draw from the grid to prevent discharge below this level. The SoC threshold can be in the region of 20%.

I'm assuming there's insufficient PV for the load demanded and so the battery would be supplying if it could.

[edited from this thread : https://electricianforum.co.uk/thre...-new-pv-installation.55104/page-3#post-531830]

hope this help

Thanks bladerunnerpv, The SoC when it happens after 4:30 is at 98% I can see from the settings that the min SoC is set at 10%. I've since checked what my energy supplier is recording for daily peek time grid usage and we are pulling an average of around .3 Kw per day so I guess that's not too bad. This is much less than i had imagined, so maybe it just is what it is... Not gonna fret about it but just an interesting anomaly tho not sure why it does it.

 

[Jedw]

@Mach13 like I said a few 100wh per day is unavoidable as you remove loads ( a kettle turns off etc) and there may be some fluctuations in the grid potential the inverter accounts for periodically. The energy company meter is not a good indicator, look at the CT linked meter or your import increase after charging, assuming your inverter capacity can meet all the demand without grid assistance.

 

[binky]

'Vamp amps' in battery systems seems to be a common complaint judging by the posts on here. Can't help thinking if this is partly down to quality of inverter algorithms and CT clamps? Most of you seem to have GroWatt or Solax inverters, which, in my opinion, are cheaper gear. It would be interesting to know if owners of say Solaredge or Solis systems see the same issues, and how much they are taking in Vamp amps. Not that Solis is an expensive brand, but the ones I have fitted use a small meter fitted into the meter tails rather than a CT clamp, which I suspect is possibly more sensitive and accurate.

 

[Ucatchmydrift]

My kit: 4Kw panels, Solax X1 5T Hybrid 5KW Inverter and 2 x Solax 5.6KW batteries. With an iBoost for heating hot water with excess energy.

Generally working absolutely fine... Apps really useful, tho doesn't seem to show particularly accurate data.. tho i'm not too fussed about that.

I'm charging the batteries overnight and the solar tops things up during the day. so daytime (peak rate) grid draw is next to zero

One thing I'm bemused about if anyone has any experience of Solax Inverters

When the batteries are set to charge between 12:30 and 4:30 obviously the inverter draws from the grid until the charge period is released.. At 4:30am id expect the batteries to take up power delivery.. Which they do for the main part..

BUT I've noticed that whenever the home power draw is less than around 100watts the inverter allows this to come from the grid.. this is usually until we get up and start drawing more power (kettle etc..) at which the draws goes to battery... NB I'm not talking about intermittent grid draws.. i'm talking draws that can last for hours- albeit of around 70-80 watts .

Is this just just one of those anomalous things that inverter systems do.. or is there a setting somewhere that will resolve it so that it always draws from the battery no matter how small the draw is?
Thoughts welcome

Hi, i have an epever inverter that annoyingly would pull a constant 10w from the grid, but if grid supply was turned off for example, at the breaker, the inverter still runs fine as it should and takes that 10w from the batteries or solar, or just doesnt need to draw 10w at all.
So i now have a contactor that switches on grid supply to the inverter from for example 12:00am to 7am economy 7 hours, or when the battery voltage gets low. This is done via a smart plug with an app. And a shunt that has relay control which also will activate the contact at low voltage set in the shunt app in case the wifi plug fails.
Works really well so far. Plus my inverter doesnt have sheduling, so the wifi plug is great for that.

Just saying, as thats one way round your problem if you dont find a soloution..

 

[MHarv]

My kit: 4Kw panels, Solax X1 5T Hybrid 5KW Inverter and 2 x Solax 5.6KW batteries. With an iBoost for heating hot water with excess energy.

Generally working absolutely fine... Apps really useful, tho doesn't seem to show particularly accurate data.. tho i'm not too fussed about that.

I'm charging the batteries overnight and the solar tops things up during the day. so daytime (peak rate) grid draw is next to zero

One thing I'm bemused about if anyone has any experience of Solax Inverters

When the batteries are set to charge between 12:30 and 4:30 obviously the inverter draws from the grid until the charge period is released.. At 4:30am id expect the batteries to take up power delivery.. Which they do for the main part..

BUT I've noticed that whenever the home power draw is less than around 100watts the inverter allows this to come from the grid.. this is usually until we get up and start drawing more power (kettle etc..) at which the draws goes to battery... NB I'm not talking about intermittent grid draws.. i'm talking draws that can last for hours- albeit of around 70-80 watts .

Is this just just one of those anomalous things that inverter systems do.. or is there a setting somewhere that will resolve it so that it always draws from the battery no matter how small the draw is?
Thoughts welcome

Hybrid G4 model
Check Settings>Advanced>PGrid BIAS
Inverter set as Default
Change to Disable to reduce Grid import

You might need a Firmware update from Solax if PGrid BIAS is not there in Advanced settings

Hope this helps

 

[johnb2713]

'Vamp amps' in battery systems seems to be a common complaint judging by the posts on here. Can't help thinking if this is partly down to quality of inverter algorithms and CT clamps? Most of you seem to have GroWatt or Solax inverters, which, in my opinion, are cheaper gear. It would be interesting to know if owners of say Solaredge or Solis systems see the same issues, and how much they are taking in Vamp amps. Not that Solis is an expensive brand, but the ones I have fitted use a small meter fitted into the meter tails rather than a CT clamp, which I suspect is possibly more sensitive and accurate.

The problem with power meters is they're slower to respond, the inverter doesn't ramp its output up quick enough when a load is applied and when a load is removed it's slow to ramp down when compared to a CT clamp. They are good at detecting zero flow in/out though. A CT clamp is excellent, very responsive at reacting to loads but dreadful at detecting zero, noise becomes significant.