Lux ac battery controller

ianatkin

Compare your setup and values to the attached example - this is how I have it set up for Octopus Go hours (00:30-04:30). If I'm not charging the car overnight and I don't need to top up the house battery then I'll untick "AC Charge Enable". Hope that helps?

Alnat1

I do it the same way as @ianatkin. Although we don't have an EV,  we often run the dishwasher/washer overnight and hubby gets up at silly o'clock for work (3.15am) and can switch the clothes to the dryer. I adjust the AC Battery Charge Level % depending how the weather  is forecast to be the next day and I turn off AC Charge Enable if we don't need overnight electricity.

Wattstored

In the darker months when solar generation is low I enable both charge and block discharge as below - it means that the house uses the Intelligent Octopus off peak rate to charge the batteries and they don't start to discharge until after 05.30 (see how I reverse the block discharge times in the second period, the first is kept empty for any temporary periods earlier in a day)

As the Lux/Pylontechs are downstream of the consumer unit, charging our two EVs never drain these batteries (9.6kW) and the 'other' PV system (which would drain) has a block discharge set for 23.30-05.30 so its own 6.7kW of batteries don't discharge either.  

At the moment (normally known a 'summer' but not sure for July/Aug this yr?!) the Lux system charges from its own (separate) PV system. 

These are my 'winter' settings which charge the Pylontechs & stop them discharging during the low peak period (ie house draws from grid 23.30-05.30). If I want to enable discharge for any day or part of a particular day I manually disable charge priority. :

chainreaction

Eric, my system is set up to do exactly what you want. So in the charge setting enable "Charge Priority" and set the times to the off peak period. This will stop your batteries from discharging during this period. If/when I want my batteries to be recharged I enable "AC Charge Enable" and set the time slot to start and finish in the off peak period, I have my grid charge power rate set at 100%, ie 3.5ish KW/h to charge the batteries and depending on what I think the solar irradiation will be the following day set the AC Battery Charge Level to anything in the range 50-100%, set at 100% the batteries will be fully charged at the end of the off peak period. If you search for solcast on this thread you'll find a website that allows you to set your system up with their solar irridiance data to give you a prediction of the kwh production for the following day. 

chainreaction

ianatkin said:

Compare your setup and values to the attached example - this is how I have it set up for Octopus Go hours (00:30-04:30). If I'm not charging the car overnight and I don't need to top up the house battery then I'll untick "AC Charge Enable". Hope that helps?

I'm interested in how your system operates with just setting AC Charge Enable and not the Charge Priority toggle aswell.
1) If your batteries are at say 40% in the above mode do they continue to meet the house load during the off peak period until they drop below 20%?
2) if your batteries are at 10% then at 00:30 your batteries will start to be charged to 20% and then stop charging. Does the inverter then want to meet the houseload and start to draw energy from the batteries and then when the battery drops to 19% it will want to start to recharge the battery again and so on?
Ian

ianatkin

chainreaction said:

ianatkin said:

Compare your setup and values to the attached example - this is how I have it set up for Octopus Go hours (00:30-04:30). If I'm not charging the car overnight and I don't need to top up the house battery then I'll untick "AC Charge Enable". Hope that helps?

I'm interested in how your system operates with just setting AC Charge Enable and not the Charge Priority toggle aswell.
1) If your batteries are at say 40% in the above mode do they continue to meet the house load during the off peak period until they drop below 20%?
2) if your batteries are at 10% then at 00:30 your batteries will start to be charged to 20% and then stop charging. Does the inverter then want to meet the houseload and start to draw energy from the batteries and then when the battery drops to 19% it will want to start to recharge the battery again and so on?
Ian

1) No, the battery just doesn't do anything in that scenario - this is the last day I can find where I charged the car off peak, the house battery was probably at quite a high %:


2) The house battery charges up to the specified % and then remains there until the end of the timer period, with the grid supplying the house load. If the house battery % sags there might be a small top-up charge, as in this example:


I agree that it doesn't really make sense for an "AC Charge" option to work in this way, but it seems to do what I'm after 🤷‍♂️

ianatkin

Quick follow-up, I have a hybrid inverter not an AC coupled, that might be relevant to how the modes behave?

Alnat1

ianatkin said:

Quick follow-up, I have a hybrid inverter not an AC coupled, that might be relevant to how the modes behave?

I have a hybrid too

chainreaction

Great thanks guys, I'll have a go tonight and set my system without charge priority toggled. It maybe the difference between hybrid and AC coupled 

EricMears

chainreaction said:

Eric, my system is set up to do exactly what you want. So in the charge setting enable "Charge Priority" and set the times to the off peak period. This will stop your batteries from discharging during this period. If/when I want my batteries to be recharged I enable "AC Charge Enable" and set the time slot to start and finish in the off peak period, I have my grid charge power rate set at 100%, ie 3.5ish KW/h to charge the batteries and depending on what I think the solar irradiation will be the following day set the AC Battery Charge Level to anything in the range 50-100%, set at 100% the batteries will be fully charged at the end of the off peak period. If you search for solcast on this thread you'll find a website that allows you to set your system up with their solar irridiance data to give you a prediction of the kwh production for the following day. 

Afraid I didn't see this in time for this morning's run but will try and adopt it next time.

Last night I set :-

AC Charge Enable :  Enabled

AC Charge Power Rate(%)  : 10

Start Time: 00:31   End Time:  04:29

and got following results from my 'Bright' app :-

This graph may be more familiar to most :-



(I wasn't of course charging the car during this test)
which resulted in imports of 2.7 kWh costing 22.3 pence (so not a very expensive test) but battery was charging at 320W   during the test so 1.28kWh would have been added to battery with 1.42kWh actually consumed as 'background use' (355 watts).

This morning I've 'disabled'  "AC Charge Enable"  and reset "AC Charge Power Rate(%)"  to 100 then boiled a kettle which was supplied wholly from the batteries.

I'll probably charge the car tonight (tomorrow morning of course) and use same setup again but test chainreaction's method later.

Although this method has worked,  I really didn't want the effort of changing parameters at bedtime and restoring to normal next morning every time I want to suppress battery discharge during off-peak period.  Really surprised that there isn't a simple way to tell system "never discharge battery during a defined period".

Incidentally I was also rather surprised that the "AC Charge Power Rate(%)"  setting operates whether or not "AC Charge Enable" is enabled.