Operating Modes on Solis Hybrid Inverter

[marky0]

Hi,
I am looking to buy a 5kW solis hybrid inverter, because it seems to be the only model I can find in the UK that will integrate with 48V LiFe
Model number is RHI-5K-48ES-5G.

I am trying to get my head around the badly worded manual and hopefully someone has this model (or similar) and can confirm its operation.
I want to use the battery and inverter with the following schedule

04:30 to sunrise -> Use the battery power available - charging battery from grid OFF
sunrise to sunset -> charge the battery from PV - charging battery from grid OFF
sunset to 12:30 -> Use the battery power available - charging battery from grid OFF
12:30 to 04:30 -> Charging battery from grid on - I have an economy tariff between these times so if the battery is at a very low state of charge, charge it from the grid during this period to a preset charge.
Repeat daily

I am confused by the instruction manual for the "self use" mode and the functions "time of use for self use" and "Charging from grid for self use", which suggests there is only one battery charge/discharge period and this is not possible ??
Does anyone have experience and if this schedule achievable with this inverter ?

Many Thanks !

 

[SiMacSee]

Similar situation for me - there is another thread which implies this is possible (my installer also thinks it is), but I'd like to see some who does this confirm it!

... watching with interest...

 

[marky0]

Contacted the Solis technical helpline. Excellent response time and very helpful. Reply was as follows :

charging from grid settings must be change manually, we can't set it for scheduled. If you enable this, it will be charging at your time of use charging time. you can set the battery charging SOC level also.
Self use is general working mode, after you set it enable you can set the charging and discharging time. If you will not set the time of use, it will keep working on self use fully automatic mode.

So in summary you can do everything but not automatically.
The different modes need to be entered manually from the front panel LCD of the inverter.
It is not possible to change these settings remotely over wifi.

For this reason I have not purchased this inverter as it would be painful to manually change the mode of the generator every evening and every morning !
UPDATE : After posting to this forum I have discovered the home assistant add-on that allows complete remote automation of this inverter with python scripts and a rapsberry pi. All from my laptop in the comfort of my front room, no manual operation from the inverter front panel (which is in my garage) needed. Purchased this inverter and couldn't be happier ! See thread below for more details.

 

[SiMacSee]

Contacted the Solis technical helpline. Excellent response time and very helpful. Reply was as follows :

charging from grid settings must be change manually, we can't set it for scheduled. If you enable this, it will be charging at your time of use charging time. you can set the battery charging SOC level also.
Self use is general working mode, after you set it enable you can set the charging and discharging time. If you will not set the time of use, it will keep working on self use fully automatic mode.

So in summary you can do everything but not automatically.
The different modes need to be entered manually from the front panel LCD of the inverter.
It is not possible to change these settings remotely over wifi.

For this reason I have not purchased this inverter as it would be painful to manually change the mode of the generator every evening and every morning !

Interesting... will ask my installer about this and see what I can feedback. He was certainly of the opinion you do need to set manual charge from grid (i.e. 4 hours on cheap-rate), but otherwise it will automatically charge the battery if excess solar available and discharge battery otherwise.

Which inverter did you go with?

 

[SiMacSee]

Quick follow-up; having sat through various Solis videos on this, I think it can definitely fore fill your needs (which are essentially the same as mine).

Essentially, it just needs to run in Self-Use mode, but with battery charging set for 12:30-04:30. In this mode, it will automatically charge/discharge battery with any excess solar/excess load (until battery full or depleted).

...Chinese to English instructions not great... although I am going to ask my installer to see if I can speak to a customer who has this setup done (there is another thread on the forum where this appears to be the case).

Solis Hybrid Inverter Charge from other PV production

Hi all, can the Solis 5K-48-5G send excess energy generated from other sources to the battery? I have 3 different PV strings but not connected to the Solis. They were installed separately so not easy to get them connected + I'd need 3x inputs which the Solis doesn't have. I'm using the Solis to...

diysolarforum.com

My next thought is where do CT meter for a Zappi EV car charger go - so that the battery isn't discharged to charge the car (99% sure it's on the battery-to-inverter cable - but the response time of the systems might not be great - i.e. zappi pulls 'excess solar', but then battery kicks in, then zappi stops, if it did that over a few seconds, could envisage the battery being drained un-necessarily, but will see what I can find).

 

[marky0]

Thanks go to @SteveC4 for giving me the answer in pdf'ed conversation below and @SiMacSee for the link to @SteveC4 post above

 

[Portugeezer]

Thanks for this useful info
One question I have and not 100% sure - if I set the inverter to charge the batteries in the day from solar, so charging time 07.00 to 18.00 for example, and do not set a discharge time, will it ONLY charge from 07 to 18 and not discharge, and then will the batteries be used from 18 to 07 ? Thanks

 

[marky0]

Hi, haven't got my solis inverter yet so can't answer the question, but I agree that the manual is really confusing !! if you contact @SteveC4 he has that inverter installed so he should be able to help.

 

[Portugeezer]

Think I’ve worked it out, I’ve set the charge time for batteries, eg 10.00 to 19.00 and haven’t set a discharge time, from what I understand and saw yesterday, the batteries will charge during these times, and not discharge, so when at 100% not used during the charge window, outside these times they will be used as normal, charge and provide power automatically. If you set a discharge time then the batteries discharge at a constant rate.
So for my use, I’m charging the batteries in the day via solar and use then at night as needed.
I’m not charging from the grid, that option turned off, only charging from the PVs during the day

 

[RichardL]

Interesting thread,
I was after an almost identical cycle - but can't see how to do it, same inverter as the OP:

Ideal
#1 04:30 to sunrise -> Use the battery power available - charging battery from grid OFF (Auto mode)
#2 sunrise to sunset -> charge the battery from PV, use battery if not enough PV - charging battery from grid OFF (Auto mode)
#3 sunset to 12:30 -> Use the battery power available - charging battery from grid OFF (Auto mode)
#4 12:30 to 04:30 -> Don't discharge & Don't Charge - this is cheap rate grid, but I'd rather use it for the ~40kWh car and save the battery for #1 above after 04:30

#4 is the challenge

I don't think I can do it based on the following tests:

Tests
Auto charge mode on
Grid charge off

Timer mode - seems to be designed for low rate charge, high rate dump scenarios only.
- Minimum charge/discharge is 4.9A
- The charge timer overrides the 'grid charging off' - it will pull the set number of Amps during the timer phase ignoring other settings.
- The discharge timer just dumps amps - obviously intended to discharge power at peak times, and doesn't balance against demand.

I was hoping to use a charge timer or discharge timer @ 0Amps to stop the house battery discharging.

Option
Can anyone see an option other than having storage larger than the electric car's 40kWh battery?


Thinking out loud - an arduino based RS485/Modbus (or can bus) relay could, in theory
a. Tell the inverter the battery was empty (when it wasn't) - to force GRID (at night)
b. Tell the inverter the battery was full (when it wasn't) - to stop GRID charge (I'm thinking a summer/winter switch)
i.e. pseudo logic:

If summer(PV during the day) - tell the inverter the battery is full from 00:30-04:30 - i.e. dont charge offpeak

One would have to be careful about the logic - to ensure it doesn't do something silly (overcharge the battery etc)

Thanks.

 

[RichardL]

Thanks for this useful info
One question I have and not 100% sure - if I set the inverter to charge the batteries in the day from solar, so charging time 07.00 to 18.00 for example, and do not set a discharge time, will it ONLY charge from 07 to 18 and not discharge, and then will the batteries be used from 18 to 07 ? Thanks

Outside the timer settings the manual (certain versions of it) say the inverter reverts to its normal mode - so Auto for example.

I'm interested if you managed to set a timer 07:00-18:00 and inside that time stopped it charging from the grid.
My brief experiment seemed to indicate the timer overrides the 'charge from grid' setting?

 

[Portugeezer]

Outside the timer settings the manual (certain versions of it) say the inverter reverts to its normal mode - so Auto for example.

I'm interested if you managed to set a timer 07:00-18:00 and inside that time stopped it charging from the grid.
My brief experiment seemed to indicate the timer overrides the 'charge from grid' setting?

I've set charge from grid off - so only charges from the PV - I don't think it is charging from the grid - (even with it set to off as you say in your first post) - will be good to test - just installed and have had lots of sunny days and during the charge period my smart meter shows zero use - will have to check when its not so sunny
I've updated the times charging from PV (i hope ) 08.00 to 10.00 & 13.00 to 19.00 - FYI - the gap in the middle of the day is when my hot tub does a 2 hour filter cycle .. so if needed the batteries can be used - I hope my logic is correct.....I'm new to this

 

[RichardL]

I could have easily made a mistake on the 'grid off' setting - I think I need to (try) and leave my new setup alone for a while to get some steady state background levels.

I suspect the 6kWh battery on the inverter is going to drain into my wife's car overnight at the low rate @ 5p grid rates and then be empty for the morning @ 15p

 

[marky0]

@RichardL if I'm not mistaken you want to do exactly the same as me and as I discussed in the private conversation with @SteveC4 (see pdf). i.e. make sure your battery is at a pre-set state charge when your cheap tariff ends - enough to run your home until sunrise.
I don't think it matters if your battery charges your wife's car during the cheap rate period*, just as long as you grid charge the battery during the same cheap rate period to return it above a pre-set charge by 04:30. This is what I want to do.

In which case @SteveC4 confirms that this is possible with home assistant and a bit of software coding, but not possible from the standard timing functions on the front panel of the inverter. I haven't got my solis installed yet so I can't confirm, but I've already played around with home assistant and it seems straight forward. Will keep you posted but not until it arrives in September !!

* Ignoring efficiency losses from your battery to inverter (which will be fractions of a pence). Nonetheless if this bothers you it appears anything is possible with some custom code and home assistant, by automatically changing the timers, charge/discharge currents, charge/discharge options and some custom triggers.

 

[RichardL]

@RichardL if I'm not mistaken you want to do exactly the same as me and as I discussed in the private conversation with @SteveC4 (see pdf). i.e. make sure your battery is at a pre-set state charge when your cheap tariff ends - enough to run your home until sunrise.
I don't think it matters if your battery charges your wife's car during the cheap rate period*, just as long as you grid charge the battery during the same cheap rate period to return it above a pre-set charge by 04:30. This is what I want to do.

In which case @SteveC4 confirms that this is possible with home assistant and a bit of software coding, but not possible from the standard timing functions on the front panel of the inverter. I haven't got my solis installed yet so I can't confirm, but I've already played around with home assistant and it seems straight forward. Will keep you posted but not until it arrives in September !!

* Ignoring efficiency losses from your battery to inverter (which will be fractions of a pence). Nonetheless if this bothers you it appears anything is possible with some custom code and home assistant, by automatically changing the timers, charge/discharge currents, charge/discharge options and some custom triggers.

Hi Marky,
Not quite, very similar except - I don't want to charge my battery from the grid at all & stop it discharging during cheap tariff.

My ideal is the cheap overnight is used for the 40kWh electric car (as now) and the battery time shifts solar into the evening/morning for general other use. If I let the battery charge the car - thats a 6kWh battery into 40kWh car - it will be empty when expensive rate starts again at 04:30

I saw your link above on the thread with Steve... + will look into home assistant.

Very early - days - but very useful to compare notes and think out-loud on options.
Many thanks for the response

 

[RichardL]

Penny drops;

@marky0
Last night the 90% full solar battery around 23:00 did later drop its charge (to the set minimum) into the 40kWh car once the car started its scheduled charge at 00:30 (cheap grid rate)

I can't stop the battery doing that - so your/Steve's approach is the best option I think,

Thus:
- In the evening pylontech is full of free solar,
- Car takes ~6kWh from the p.tech so draws ~6kWh less from the grid @ cheap rate
- Therefore... use some of the 6kWh the car would have pulled to top up the py.tech battery from grid to cover 04:30 until sunrise

Net result better off - shifting solar into the car overnight, and cheap rate overnight into the battery until sunrise

Interesting

 

[marky0]

There is another option to turn off your inverter during your cheap rate period.
Page 17 of the solis manual says

4.8 Logic interface connection (Only for UK)
Logic interface is required by G98 and G99 standard that can be operated by a simple switch or contactor. When the switch is closed the inverter can operated normally. When the switch is opened, the inverter will reduce its output power to zero within 5s. PinS and Pin6 of RJ45 terminal is used for the logic interface connection. Please follow steps below to assemble DRM RJ45 connector. 1.Insert the network cable into the communication connection terminal of RJ45....................

So you could simply use a timer relay on this connection. This is something I have considered. But I prefer a software approach providing I can get Home Assistant working. This way I can charge the battery to a preset SOC (for example in winter) so it has enough juice at the start each day.

 

[RichardL]

There is another option to turn off your inverter during your cheap rate period.
Page 17 of the solis manual says


So you could simply use a timer relay on this connection. This is something I have considered. But I prefer a software approach providing I can get Home Assistant working. This way I can charge the battery to a preset SOC (for example in winter) so it has enough juice at the start each day.

Thats interesting... not even hacking either - standard designed in functionality.

Nice.

Thoughts, potential configuration:
- Solis set to charge the batteries for 00:30-04:30 (off peak grid)
- Timeclock and switch in parallel with the UK Logic interface (on off switch)
- Timeclock turns off the inverter during cheap grid overnight - stopping the battery trying to charge the car, or charge itself from the grid
- Switch (or winter/summer clock) can override the timeclock - so in winter with less solar, leaves the inverter on to charge the battery

Thats 2x timeclocks 0 volt switches/relays across the logic interface.

Very interesting.
All off the shelf parts too.

 

[RichardL]

Ideas;

Even better although more complex:
Talk to the pylontech's on the RS485 (currently unused on my inverter which uses CAN)

The inverter on/off in the cheap grid 00:30-04:30 could make some informed decisions based on how much the battery charged today, and how full it needs to be at 04:30 to cover tomorrow morning ... and therefore if to turn on before 04:30

Equally during charge the RS485 will tell you when there is enough charge and the inverter can be turned off until 04:30

A look table something like:

Charge @ end of today	Target charge for tomorrow morning	Start charging @ (turn the inverter on at)	Comment
100%	100%	04:30	Full, probably summer - don't charge overnight
50%	50%	03:00
10%	65%	03:00	Probably winter - not much solar, bigger topup over night
0%	100%	02:00	No solar! fill up

It would get it wrong and overcharge / miss out on those random sunny days, but otherwise simple to catch most scenarios & avoid burning expensive grid power after 04:30.

Outside those rules the inverter is shut down at 00:30 and back up at 04:30


Wouldn't necessarily need information about time of year.

Thats more an arduino for the logic and talking RS485 + a small relay to close the volt free contacts on the inverter.

Just thinking out loud - I guess first step is to test that inverter on/off function.

 

[RichardL]

Scrap all that complexity

Turns out - discharge limit can be set to 0 amps! (charge limit can only go as low as 5)
Tested it and while it doesn't drop to 0, it reduces the battery draw to 200w or so and the inverter pulls from the grid instead.

Therefore - (to be confirmed overnight) - the attached config:

Discharge limit = 0
Discharge time = 00:29-04:31 (the cheap grid time when the electric car charges)

As per the manual - outside these times it reverts to normal 'self use' mode - prioritising PV/Battery over grid.


My expectation is this minimises battery draw overnight and starts using the battery again when peak grid starts around 04:30, and importantly the car has stopped charging its 40kWh battery.

If it works - that keeps things simple for my setup, the solar+battery runs the house, and the electric car, only at home overnight, charges from off-peak grid.

Update from overnight - works so far
Worked fine - yesterday evening ~75% battery and this morning I still have ~%50 left, the car charged in the off peak window from grid rather than battery.

One final minor tweak - I may change the discharge limit to ~1.5A in this period - the house base load.

That will force a 1.5A/350W continuous discharge which will end up in initially the car, but when it stops charging sometime around 2-3am, will power the house & if the house doesn't use it the hot water diverter will take it.

That feels like it's as good as I can get.