Solis RHI 6K 48ES 5G Inverter Fox ESS LV5200 Battery - Charging limit ? and export to grid ...

Hi All

Not an electrician and some of this is now going over my head, but new PV install with Solis inverter and Fox battery as above...

Issue is according to Solis cloud data we are seeing energy production but battery is only charging "slowly" and at times most of the energy produced is going to the grid.

We have checked standard setting for self use is set, I have been onto installer and also Solis support and am getting conflicting information.
E.G.
Yield 2.15 kw. Battery 23% and being charged at 0.653kw, house consumption 0.482kw and 1.015kw going to grid.

We have requested system is set to self use - priority - House then battery then grid. This is what we were told it would do but so far has failed.
Since install about 2/3 weeks ago we have exported almost 14kw to the grid and have on average only had a battery charge of around 30 % during the day...

Solis are saying that " the charge limit of battery is 12A . 12A x 50V = 600W limit of charge power. So the rest will go to grid"
This kind of supports the data example above however, I have disputed that as the battery should be able to charge at 3000w I believe looking at information.
Installer says I need to talk to my boss, it shouldn't be doing that

I have in fact seen yesterday BMS Charge current limit was 50 A with a voltage of 52 ? 50 x 52 = 2600w

Does this battery ONLY charge at 600 or so watts ?
Is there anyone who has the same set up and no issues?
Is there anyone who has experienced the same ?
Is this a BMS issue re Charge rate?
Is it the settings on inverter maybe ?
Is this possibly an issue with CT clamps being installed wrong?
Any pointers would be great as right now we are "losing" over 10% yield to grid and then buying back ... and I am getting the run around - just want to be able to press either the installer or Solis to get resolution.

Any help really appreciated!

It could be the charge limit setting on the BMS.
Can you access the BMS settings?
I would check this first.

Thanks Tim- I will need to climb up into loft space as this is where Inverter and battery live... I will trawl the Solis manuals etc to see what menu its all in etc... and then try and capture settings... not sure I want to go messing with any settings without being 100% sure ...

I am having a simular problem solis hybrid inverter and fox lv5200 battery but it will put 1298 to the battery and anything over this to the grid, its very annoying when the battery is knly on 40%

GBRDBRY said:

...
We have requested system is set to self use - priority - House then battery then grid. This is what we were told it would do but so far has failed.
Since install about 2/3 weeks ago we have exported almost 14kw to the grid and have on average only had a battery charge of around 30 % during the day...

Click to expand...

That is correct. Self use will power house first, then charge battery with any spare. Export to grid should not happen until the battery is full, UNLESS the Solis has been configured to limit charge current. Our Solis 3.6 will charge up to 62.5A, and I believe the 6Kw version will peak up to 100A, so that shouldn't be the case.

Check 'charge limitation' is set to 000.0A (= disabled in the 'control parameter' page.

GBRDBRY said:

Solis are saying that " the charge limit of battery is 12A . 12A x 50V = 600W limit of charge power. So the rest will go to grid"

Click to expand...

They are correct that your battery is only charging at about 12A, but given no reason why that would be the case. As @timselectric noted, the battery pack itself may be limiting the current it is charging at. This could happen if the battery is 'clever' and it's < 5 degrees and the battery is nearly full, but as the issue has been happening for 2/3 weeks, obviously not the case.

GBRDBRY said:

This kind of supports the data example above however, I have disputed that as the battery should be able to charge at 3000w

Click to expand...

Agree.

GBRDBRY said:

I have in fact seen yesterday BMS Charge current limit was 50 A with a voltage of 52 ? 50 x 52 = 2600w

Click to expand...

From BMS data from the battery pack, I assume you mean?

GBRDBRY said:

Does this battery ONLY charge at 600 or so watts ?

Click to expand...

No... unless faulty... it would be worthless if it did!

GBRDBRY said:

Is it the settings on inverter maybe ?

Click to expand...

Possibly - see above.

GBRDBRY said:

Is this possibly an issue with CT clamps being installed wrong?

Click to expand...

I can't think how that would trigger grid export if battery not charged up. Be interesting to see what the Solis main screen is showing - e.g. does it show the grid export amount as you measured. WT* do these get installed in lofts anyway.

GBRDBRY said:

... press either the installer or Solis to get resolution.

Click to expand...

your contract is with the installer (assuming they supplied the hardware), so push them hard.

Just did a search about this issue and found an almost identical posting here...


Seems a bit of a co-incidence, assuming that is not your pseudonym! ?‍

Interesting that the issue looks like battery BMS setting.

I have attached a screen shot of mine showing power sending to the grid. I don't want any going to the grid untill the battery is full. What settings should I be checking please. Sorry to hijack the post but feel our issues are probably of the same settings

There seems a thread here .... happy we don't feel so alone I guess...

My take is that I need to climb into the 10ft high opening into our loft and crawl over to the installation and check what the Inverter is set to .. it has to be the battery BMS settings - FOX is a standard setting apparently, but is that the right battery (low voltage) setting for the solis hybrid inverter .. The battery I am convinced should charge at 100 a 50 v - giving max just over 5kw charge.. not the 600 w Solis support have stated.. I suspect its set wrong, however the weird thing is it seems inconsistent, but after 2-3 weeks I don't trust the data Solis (China) data is staying at all - Solis hand off to Solarman and then back again apparently ... with wifi datalogger - had issues with that already and a firmware update ...
I will check the same post SeaGal put up - its not me BTW
Also seems coolcarper1 does have the same issue...
My brother in law is an electrical engineer and understands this harry potter stuff like the back of his hand, so I am going to drag him into the issue ....

Out of interest I have an open ticket with Solis UK support. They must have done some changes (no notification of what yet etc) on the Inverter as the battery stopped at 19% SOC yesterday afternoon and excess power is now going to battery and not out to grid... see attached screen grabs from this morning .... I am going to find out what exactly they have changed in the BMS etc .. will let you know. Will monitor closely though ....

GBRDBRY said:

... as the battery stopped at 19% SOC yesterday afternoon and excess power is now going to battery and not out to grid...

Click to expand...

can you clarify what you mean? Sorry if I'm having a blonde moment, but if excess power is going to the battery that doesn't correspond with you saying 'the battery stopped at 19%'

It stopped discharging yesterday after midday at 19% SOC - previously since installation it had gone down to approx. 10% each day, so I deduce Solis support have remotely made changes to the BMS sometime yesterday afternoon - set the limit for discharge to 20% and also made changes to the Charge rates as it all seems to now be behaving ... The FOX battery does indicate on tech specs it can discharge to 10 % though ... I have requested they tell me exactly what changes they have made so I can a) know myself and b) share here ...

GBRDBRY said:

It stopped discharging yesterday after midday at 19% SOC - previously since installation it had gone down to approx. 10% each day, so I deduce Solis support have remotely made changes to the BMS sometime yesterday afternoon - set the limit for discharge to 20% and also made changes to the Charge rates as it all seems to now be behaving ... The FOX battery does indicate on tech specs it can discharge to 10 % though ... I have requested they tell me exactly what changes they have made so I can a) know myself and b) share here ...

Click to expand...

Mine is set to 20% but will go below this but just at small amounts and will force charge at 10% back up to 20%.
It will be Interesting to see if it charges your battery only now untill full before sending to the drid

Yes - That is what I will monitor closely .. however I doubt we will make 100% charge today ... sky is grey
will keep this thread open and update when I have data / information ...

Looking at weather (Ventusky) tomorrow looks to be a great day for Solar here at this time of year - almost 0% cloud cover so will monitor and update findings then....

Sounds like some progress then. Can't see how Solis can make any changes to the BMS as the BMS is part of the Fox battery pack. But maybe they updated the Solis firmware to address a known issue with that battery type? Keep us updated.

Plot thickens as the ip address of the datalogger on my network has changed..... Solis has def been under the bonnet ...

I don't know anything about the data logger or how to use it, I'm at a loss with this tech

GBRDBRY said:

Plot thickens as the ip address of the datalogger on my network has changed..... Solis has def been under the bonnet ...

Click to expand...

Call me paranoid, but I would find it of immense concern that a Chinese outfit could tinker like that without you knowing and agreeing to what they may do.

Our Solis is completely stand-alone. I'm not sending any personal data to Chinese cloud servers ?‍

Until I can find a different monitoring solution, I am stuck with the datalogger and the Solis cloud... If there are any suggestions I would appreciate it - what works with the Solis Hybrid Inverter ...

Pitching in, I have a similar system and have noticed my battery only charging at 650w since the 16/11. When im going into the advanced settings and trying to change the charge limitation (as suggested 0A above or even 40A as it was set before by the installer) it does not save my changes! It revert back to the 12A limit. I was wondering if that's a temperature limitation as I can see a 'LowTemp.BMS' entry in the data log since the issue occurred. It has been between 5 and 12degrees here since the past week, my attic is not well insulated but even then, I struggle to understand why it would revert back to the 12A limit. Next saturday seems to be close to 15degres where I am so will be doing some testing that day.

Unfortunately, without a lot of DIY tinkering, there aren't (AFAIAA) any off the shelf alternatives to include battery monitoring.

tyrian said:

... I was wondering if that's a temperature limitation ...

Click to expand...

Possible and technically, yes. But, I would only expect such a low limit if the cells were nearer to 0 than 5 degrees and would not expect any limitation above 10.

Am I correct in thinking the Fox lv 5200 battery should be capable of being charged at 100a approx 50v = 5000w ? Solis are still staing that there is a charge limit of 12a and they can do nothing about it ... this means max charge would be 600w ....
I suspect as previous comment that their std settings on selecting FOX as a battery is wrong .... and you would need to set up a user defined battery ...
I have also found a FOX ESS forum so have asked the question there as well ...

Spec for Battery : https://www.fox-ess.com/wp-content/uploads/2021/09/LV5200-User-Manual-En.pdf

OK, bit confused now... thought you said earlier that ...

GBRDBRY said:

Solis support have remotely made changes to the BMS sometime yesterday afternoon - set the limit for discharge to 20% and also made changes to the Charge rates as it all seems to now be behaving

Click to expand...

but I now assume the issue remains?

You also say...

GBRDBRY said:

Solis are still stating that there is a charge limit of 12a and they can do nothing about it

Click to expand...

If Solis are saying the Solis has a charge limit of 12A, that sounds wrong, totally illogical and useless.

If they are saying that the Solis is being instructed (via messages from the battery) that the battery is imposing a charge limit of 12A, then they are correct, the Solis is correctly doing what it is told.

To answer your other question... yes, in theory Fox spec says 100A is max charge current. But that would be a charge rate of 1C which is high for longevity. Much better to aim for 0.5C or lower to keep everything lasting longer.

It may be me who is confused and causing confusion - sorry ...

Solis are saying the battery has a charge limit in BMS of 12a. As you say I get they cant change the Battery management software...
But is this "normal" a PV system can only charge the battery at 0.6kwh ?

I don't have knowledge of 1C or 0.5c ....

Tyrian in a previous comment stated that their system was set to 40a previously .... which would give 40 x 50 = 2000w... I have def seen the battery being charged at much more then 600w... but if there is a limit of 12a then how can this be ?

I guess I really need to see how it all performs when the sun is actually shining ..... today has been a low yield day so we can see the performance ...

GBRDBRY said:

...
But is this "normal" a PV system can only charge the battery at 0.6kwh ?

Click to expand...

No unless the battery is either a) near 100% SOC and current is limited to allow balancing to take place or
b) near freezing point and the manufacturers had implemented some gradual low-temp cut off