Solis inverter program battery charging from the grid

[harbour man]

Hi we are in East Lothian and newbies to solar we are monitoring battery discharge against PV generation especially when its cloudy and not performing well we are a wee bit confused as we are not really tech!
Question is:- is there a way to program our solis inverter to take from the grid when battery capacity reaches a set point say 15% capacity ? Charge the batteries (2× puredrive 5kw )back up to say 80% or as like you say running back and forward to the inventor in line with the forecast any help most gratefully received

 

[SeaGal]

Welcome! Quite a few of us Solis owners in the UK on here

You can force charge at specified SOC, but probably more useful to you is charging up during cheap rate time - see guide here.

Solis Hybrid Inverter: charging from the grid

How to configure your Solis Hybrid Inverter to charge from the grid on schedule.

blog.jonsdocs.org.uk

I don't see any gain in charging from grid at standard rates as you will lose some energy in the conversion losses.

 

[harbour man]

Welcome! Quite a few of us Solis owners in the UK on here

You can force charge at specified SOC, but probably more useful to you is charging up during cheap rate time - see guide here.

Solis Hybrid Inverter: charging from the grid

How to configure your Solis Hybrid Inverter to charge from the grid on schedule.

blog.jonsdocs.org.uk

I don't see any gain in charging from grid at standard rates as you will lose some energy in the conversion losses.

Hi thankyou we are on a fixed rate tarrif until Feb 24 so really using the grid to top up and maintain batteries we wondered if we could program the inverter to take from the grid when the batteries got to a low set point say 12 Or 15%

 

[rpdom]

Good morning.

The inverter default is to use the grid when the batteries are too low, so you don't really need to do anything, but there are two main settings for the batteries that you could look at here.

OverDischarge SOC %. When the charge gets to this level the inverter stops supplying power to your house. All power will come from the grid. The default for this setting is 20%. Some batteries can be set to go lower. I have set my Pylontech batteries to 10% which is well within their specifications.

ForceCharge SOC % As @SeaGal mentioned. When the charge gets this low the inverter will use the grid (unless disabled) to top up the batteries a little (2-3%), just to stop them going too low. I believe the default is 15%. I have mine set to 8%. The minimum for my Pylontech batteries is 5%, but I wouldn't set it that low.

The inverter powers itself from battery or solar. It doesn't use the grid for anything other than charging the batteries when needed/scheduled.

Other than the ForceCharge SOC, it isn't worth charging the batteries using standard rate electricity. You will be wasting money. Let the batteries drop to their cutoff point and you will be using grid with no losses.

 

[harbour man]

Good morning.

The inverter default is to use the grid when the batteries are too low, so you don't really need to do anything, but there are two main settings for the batteries that you could look at here.

OverDischarge SOC %. When the charge gets to this level the inverter stops supplying power to your house. All power will come from the grid. The default for this setting is 20%. Some batteries can be set to go lower. I have set my Pylontech batteries to 10% which is well within their specifications.

ForceCharge SOC % As @SeaGal mentioned. When the charge gets this low the inverter will use the grid (unless disabled) to top up the batteries a little (2-3%), just to stop them going too low. I believe the default is 15%. I have mine set to 8%. The minimum for my Pylontech batteries is 5%, but I wouldn't set it that low.

The inverter powers itself from battery or solar. It doesn't use the grid for anything other than charging the batteries when needed/scheduled.

Other than the ForceCharge SOC, it isn't worth charging the batteries using standard rate electricity. You will be wasting money. Let the batteries drop to their cutoff point and you will be using grid with no losses.

Thank you so much it's starting to make sense now

 

[rpdom]

Thank you so much it's starting to make sense now

Anything else you'd like to know, just ask us. I've had my Solis system just over a year now and am really getting it fine tuned for best use. Others have had theirs longer.

 

[SeaGal]

using the grid to top up and maintain batteries

As @rpdom also said, there is no point in doing that. The batteries will be fine going down to whatever over discharge % you choose, and then idle until the sun comes up (albeit behind clouds in Scotland ). Then they should charge back up again during the day, assuming that your house load is not drawing more than the sun is providing.

You will have more options if you go to a more flexible tariff next year. We have economy 7, so for the summer 6 months are self-sufficient, during the next month or so, I'll use solar and battery during peak rates (8am to midnight) and just draw from E7 cheap rate overnight (i.e. not use batteries). Then in the Winter months, charge up the battery to whatever SOC I feel is needed cheaply overnight to get me going through the next day... the latter requires a bit of forethought the day before to work out how sunny the next day will be and how many ? I might need to wash!

Anything else you'd like to know, just ask us.

Agree - either ask us with a posting on here or use the search - @rpdom, @Solar Guppy and myself have posted a lot about the Solis over the last year or so.

Final thought... thinking ahead to you running the system over the winter in Scotland - the battery will need to be kept above 5 degrees, preferable 10 to 15 degrees C to charge correctly. So if it has been installed in an unheated garage or loft you might want to think about insulation / heating before it gets cold.

 

[rpdom]

You will have more options if you go to a more flexible tariff next year. We have economy 7, so for the summer 6 months are self-sufficient, during the next month or so, I'll use solar and battery during peak rates (8am to midnight) and just draw from E7 cheap rate overnight (i.e. not use batteries). Then in the Winter months, charge up the battery to whatever SOC I feel is needed cheaply overnight to get me going through the next day... the latter requires a bit of forethought the day before to work out how sunny the next day will be and how many ? I might need to wash!

I'm currently looking into switching my tariff for the winter. I'm with Octopus, currentl on Flux for import and Outgoing Fixed for export. I'll leave the export, but am considering : "Go" with a very cheap overnight rate, "Agile" with a 30-minute tracking rate which can go negative at times, and "Cosy" which has a cheap overnight and early afternoon rate, but an expensive 4pm-7pm rate (where I should be running off solar or batteries, so I don't care).

Final thought... thinking ahead to you running the system over the winter in Scotland - the battery will need to be kept above 5 degrees, preferable 10 to 15 degrees C to charge correctly. So if it has been installed in an unheated garage or loft you might want to think about insulation / heating before it gets cold.

This is something I'm thinking of setting up, even here in the South. My batteries did go down to around 0°C last winter, and although it isn't low enough to cause any damage, they won't charge below 5°C and have a reduced charge rate at under 10°C. I'm considering a heat mat taped to one side of each battery with a thermostat of sorts.

 

[harbour man]

As @rpdom also said, there is no point in doing that. The batteries will be fine going down to whatever over discharge % you choose, and then idle until the sun comes up (albeit behind clouds in Scotland ). Then they should charge back up again during the day, assuming that your house load is not drawing more than the sun is providing.

You will have more options if you go to a more flexible tariff next year. We have economy 7, so for the summer 6 months are self-sufficient, during the next month or so, I'll use solar and battery during peak rates (8am to midnight) and just draw from E7 cheap rate overnight (i.e. not use batteries). Then in the Winter months, charge up the battery to whatever SOC I feel is needed cheaply overnight to get me going through the next day... the latter requires a bit of forethought the day before to work out how sunny the next day will be and how many ? I might need to wash!


Agree - either ask us with a posting on here or use the search - @rpdom, @Solar Guppy and myself have posted a lot about the Solis over the last year or so.

Final thought... thinking ahead to you running the system over the winter in Scotland - the battery will need to be kept above 5 degrees, preferable 10 to 15 degrees C to charge correctly. So if it has been installed in an unheated garage or loft you might want to think about insulation / heating before it gets cold.

Big thanks for helpful info it's a huge learning curve for us and yes the batteries are in the house under stair cupboard so the should be well protected from the lower temps we are with edf at the moment but will enquire about a transition to economy 7
Tx again

 

[SeaGal]

..but will enquire about a transition to economy 7

... look into either E7 or one of the newer, more flexible tariffs that Octopus now offer ?

 

[SeaGal]

This is something I'm thinking of setting up, even here in the South. My batteries did go down to around 0°C last winter, and although it isn't low enough to cause any damage, they won't charge below 5°C and have a reduced charge rate at under 10°C. I'm considering a heat mat taped to one side of each battery with a thermostat of sorts.

Yep... mine kept at a toasty 20 - 25 degrees all last winter when we had it down to -4C ambient temp in East Anglia on a few occasions. I have 15W of heaters within the battery compartment, surrounded by 50mm of PIR/Celotex. Heaters were only on about 50% of time in cold spells.

 

[harbour man]

Big thanks for helpful info it's a huge learning curve for us and yes the batteries are in the house under stair cupboard so the should be well protected from the lower temps we are with edf at the moment but will enquire about a transition to economy 7
Tx again

Sorry today has been overcast and cloudy but now it's fairly sunny and PV is generating I'm confused Solis shows it's exporting to grid but batteries are only around 47% I would have thought the priority would be PV charge batteries and export when they are full I can't understand why I'm exporting ??? Any setting I need to look at please

 

[SeaGal]

Sorry today has been overcast and cloudy but now it's fairly sunny and PV is generating I'm confused Solis shows it's exporting to grid but batteries are only around 47% I would have thought the priority would be PV charge batteries and export when they are full I can't understand why I'm exporting ??? Any setting I need to look at please

The default 'mode' is "self-use" and, as you say, the priority is as follows:-

a) PV generation will supply house load.
b) Once house load is supplied by PV, the Solis will charge batteries at the rate the batteries request.
c) Once PV load exceeds house load _and_ battery charge rate, excess will be exported.

IIRC Top left of the main Solis screen should show the mode and current status (e.g. Self-use & Normal).

Note that:-

1) All of the above require a correctly installed and configured power meter (either Acrel or Eastron are supported), connected via RS485
2) Batteries will typically take the maximum the inverter can supply them (62.5A for the lower end models and 100A for the 5kW and 6kW inverters). However, they will normally request a lower rate of charge if they are cold (below 10 or 15C) and/or if they are nearly fully charged (e.g. 90%+)
3) Export can additionally be limited by enabling EPS mode and specifying a maximum export power. Once that export limit is reached the Solis will reduce the amount of power it takes from the PV panels.

Are the batteries charging at all, or is there no charge going to them? If all looks OK on the Solis side of things, check if your batteries have any configuration / control settings that may be limiting their charge rate.

 

[harbour man]

The default 'mode' is "self-use" and, as you say, the priority is as follows:-

a) PV generation will supply house load.
b) Once house load is supplied by PV, the Solis will charge batteries at the rate the batteries request.
c) Once PV load exceeds house load _and_ battery charge rate, excess will be exported.

IIRC Top left of the main Solis screen should show the mode and current status (e.g. Self-use & Normal).

Note that:-

1) All of the above require a correctly installed and configured power meter (either Acrel or Eastron are supported), connected via RS485
2) Batteries will typically take the maximum the inverter can supply them (62.5A for the lower end models and 100A for the 5kW and 6kW inverters). However, they will normally request a lower rate of charge if they are cold (below 10 or 15C) and/or if they are nearly fully charged (e.g. 90%+)
3) Export can additionally be limited by enabling EPS mode and specifying a maximum export power. Once that export limit is reached the Solis will reduce the amount of power it takes from the PV panels.

Are the batteries charging at all, or is there no charge going to them? If all looks OK on the Solis side of things, check if your batteries have any configuration / control settings that may be limiting their charge rate.

Thank you so much:- yes batteries charging normally up to 100% I will check the solis setting and monitor it for a few days what a learning curve this is !!

 

[Chloelouz]

Can someone please help? We recently got a new fuse box so all power had to be off for several hours to allow for this. When the power was put back on our battery (PureDrive) had disconnected from our Solis inverter. We managed to connect them again however we now no longer seem to use our stored energy? It’s night time and we have various lights and appliances on and the battery is still up at 97% which it will stay at. Before we had the fuse box replaced it would run down to 5% and then start to charge from the grid. I would like to change the settings back so we use our own stored energy as opposed to using from the grid!

 

[rpdom]

I suspect your CT clamp has been put back incorrectly, so your inverter can't detect the load. Notice the house load is showing 0.00kW in your picture and it is also showing 2.43kW being exported to the grid. If you turn on a kettle does that figure go up and not change direction? If so the clamp is the wrong way round.

It should be clamped around one of the Live wires connected to your meter. There is an arrow on it. If you unclip it from the wire and turn it so the arrow faces the other way, does that fix the problem?

The clamp detects the amount and direction of the current flow, so it is essential it is the right way round. It's worrying how many electricians don't realise that.

 

[Gray17]

Morning Guys, read this post with interest as have a similar issue which perhaps you can comment on.
I did reason whether to start a new post as my inverter is Solax SK-SU3700E 3.7kw rather then a Solis but works same way.
Like original poster i have battery storage in my case 100ah made up of 4 x 12v 50ah Lifepo4 in series making 48v + a further 48v 50ah in parrallel total 48v x 100ah. No comms but all have their own built in BMS.
Soc is set to 20%, min cut off 43v, max 58v.
Issue: inverter is set to self use mode therefore as stated gives priority to home load 1st, then batts, any excess to grid (this in my case is limited)
So solar usually kicks in about 8am this time of year in uk, inverter starts powering home load and charging batts, so far so good, however because of limited solar generation batts never reach full capacity (they did in summer) so round about 5pm solar generation in uk at minimum (0) so home load is powered by batts and if needed supplemented by the grid.
Batts last all night supplementing as have very low quiescent loading. Trouble is inverter never goes into sleep mode as batts seem to keep inverter powered all night even though only supplying 0.1a and at min set voltage of 43v (so should cut off, but doesnt) so remainder from Grid meaning im paying to power inverter when its not doing anything and should shut down, but doesn't.
Is this correct or do the settings need altering?
If i turn batts off, inverter goes into sleep mode as soon as solar panels stop generating, which is as expected.
Incidentally home load is 250w with inverter powered, but if i disconnect inverter from grid, by turning off breaker. Nightime load with everything turned off, bar fridge, freezer, clocks etc is 50w.
Suggestions Guys?
Thanks

 

[rpdom]

I don't know how the Solax works, but that is normal operation for the Solis hybrids. The inverter will stay on as long as it has battery or PV power. Mine (3kW) doesn't take that much power though, less than 100W for itself.

I recall someone mentioned a firmware upgrade for the Solis which reduced its power usage. Maybe Solax has similar?

 

[Chloelouz]

@rpdom thank you so much for your reply! The 0.00kw never changes, so odd! I think I have found the clamp, do I need to change the direction of this? Sorry I’m clueless!

 

[Gray17]

Thanks for replies Guys, that good to know.
Chloe- Yes thats correct, as mentioned, theres an arrow on the CT clamp check which direction its currently facing, then open clamp up and reverse it so the arrow faces the opposite way to it was before, then see if that makes a difference by turning on a kettle and see if consumption is registered on display. Incidentally CT are usually on the Brown ( Red) Live cable, however they will work on the Neutral Blue
(Black) but in this case the sensing is reversed ie the arrow faces the opposite to what it would if it was on the live.
Hope that helps

 

[SeaGal]

I think I have found the clamp

Yes you have.

do I need to change the direction of this?

we can't see from the pic which end of your cable is connected to the grid and which to the meter. But as it is not working at the moment, just reverse it, retest and report back to us.

 

[sedmead0]

Welcome! Quite a few of us Solis owners in the UK on here

You can force charge at specified SOC, but probably more useful to you is charging up during cheap rate time - see guide here.

Solis Hybrid Inverter: charging from the grid

How to configure your Solis Hybrid Inverter to charge from the grid on schedule.

blog.jonsdocs.org.uk

I don't see any gain in charging from grid at standard rates as you will lose some energy in the conversion losses.

I am very late to this thread, but I would like to thank you for posting this 'how to' guide. I have just followed it and it worked a treat. Great that we can get the solar batteries working for us over Winter and store ultra cheap overnight electricity for use next day. Steve Edmeades

 

[SeaGal]

@sedmead0 thanks.... and Welcome!

 

[sedmead0]

thanks - seems like a nice community here! I am just a novice who might occasionally tinker with this stuff. Thanks to info supplied here I can now charge our 2x pylontech batteries overnight on the octopus e-vehicle tariff (very cheap atm !) . This will supply the house until early evening. Am I right in thinking the battery minimum can be set to 10% to stretch this further (currently 20%)? that is the OverDischarge SOC % i saw someone mention ? It also occurs to me that I could help the grid loading if we delayed drawing on batteries until later in the day (although at no financial advantage to us) - is it possible to program the inverter to do this.. ie discharge to the house from a certain time.

 

[SeaGal]

Sure, you can set the OverDischargeSOC% to 10%. IIRC Pylontech's claim they support 95% DoD. You may want to check the voltage of the cells when they get to 10% to make sure, but the cells themselves will be protected by the Pylontech's BMS anyway.

The only thing to note is that the Solis will still consume about 30W of power from the batteries to power its own electronics once the OverDischargeSOC is reached and hence reduce the SOC a bit more. So you will need to set the ForceChargeSOC% to a value lower than the OverDischargeSOC by the amount of quiescent usage, otherwise the force charge will kick in to boost battery voltage during your peak rates.

FYI and as a rough guide... our 14.3kWh pack only discharges about 1% per 3 hours.

With regard to preventing the Solis from using the battery at certain times, one way you can do that is to set a TOU slot to "discharge" but set the "discharge current" to zero amps.

On a related note, it sounds like you'd benefit from purchasing a 3rd Pylontech so you can continue using the cheap electricity until the next night rate kicks in. We haven't used any peak electricity for 2 years now!