Configure MultiPlus II to use AC In only for battery charging during a specific time period

I have an "off grid" setup which uses a 48v MultiPLus II, Cerbo GX, a couple of MPPT Charge controllers and a 48v LiFEPO4 battery..so far so good. I'm trying to find out if I can utilise the "AC In" on the MultiPlus II to charge my battery during a specific time window each day (at night when the rate is cheaper)?
I've looked at the "Scheduled Charging" option that's available with ESS, but enabling that, also seems to suggest that it will use the "AC In" to export any "spare" solar power back into the Grid and I don't want to do this.
I've also seen some videos that suggest you can setup some "Relay" assistants that "enable" and "disable" the AC In connection based on the SOC of the battery. This is the sort of thing I want to do but I want to incorporate a "time of day" condition as well i.e. if the time is between 02:00 and 07:00 and the SOC is lower than 60% then enable the AC In to charge the batteries.
Can anyone point me in the right direction or let me know if there's any other way to achieve what I want to do?

Cheers for now

Russell

Yes it looks like you could use the generator start/stop option (I believe the same as what you mentioned above) of the Cerbo to control a “periodic” runtime. You could set it to every day at a specific time.

I just use a smart switch to power a contactor that turns grid power on. Might be a crude, brute force approach, but this has been working flawlessly for 18months on my 4 x Multiplus 24/3000 inverter split phase system. I turn power on to charge during off-peak hours and run all my major loads on-peak off the batteries.

Adam De Lay said:

Yes it looks like you could use the generator start/stop option (I believe the same as what you mentioned above) of the Cerbo to control a “periodic” runtime. You could set it to every day at a specific time.

Click to expand...

Thanks Adam,

It was one of your YouTube videos that I watched last night, that suggested that I could do this Presumably, I'll have to use the wired connection from the Cerbo to the MultiPlus, as per your video and then enable the schedule as per the screenshots?

Cheers for now

Russell

groot59 said:

I just use a smart switch to power a contactor that turns grid power on. Might be a crude, brute force approach, but this has been working flawlessly for 18months on my 4 x Multiplus 24/3000 inverter split phase system. I turn power on to charge during off-peak hours and run all my major loads on-peak off the batteries.

Click to expand...

Thanks, I was thinking of something like that as an option using a timer switch normally used for immersion heaters or similar

Ruburnel said:

Thanks Adam,

It was one of your YouTube videos that I watched last night, that suggested that I could do this Presumably, I'll have to use the wired connection from the Cerbo to the MultiPlus, as per your video and then enable the schedule as per the screenshots?

Cheers for now

Russell

Click to expand...

That's correct.

I just went and checked to see if you could enable the time-based condition using the generator start/stop assistant in the MP to skip the Cerbo connection (figuring you're probably gonna set it once and leave it alone). Unfortunately there's no time-based condition in the assistant, so you would have to use the Cerbo for that (or the smart switch as @groot59 suggested).

Adam De Lay said:

That's correct.

I just went and checked to see if you could enable the time-based condition using the generator start/stop assistant in the MP to skip the Cerbo connection (figuring you're probably gonna set it once and leave it alone). Unfortunately there's no time-based condition in the assistant, so you would have to use the Cerbo for that (or the smart switch as @groot59 suggested).

Click to expand...

I've just been trying to configure the Generator Start/Stop functionality via the Cerbo, and can get everything setup so that it looks like it should only enable the "AC In" for a few hours every day, but whenever I switch the AC breaker on it just starts charging! I think it might be due to the fact that I can't change the "Ignore AC input" option (as per the screen shot below) :-(

Ruburnel said:

I've just been trying to configure the Generator Start/Stop functionality and can get everything setup so that it looks like it should only enable the "AC In" for a few hours every day, but whenever I switch the AC breaker on it just starts charging! I think it might be due to the fact that I can't change the "Ignore AC input" option (as per the screen shot below) :-(

Click to expand...

What you're showing in the image is just an indicator, it's not actually a control.

Did you configure the relay assistants in the MP as well? The connection from the Cerbo to the MP is what tells the inverter to Use or Ignore AC In.

Adam De Lay said:

That's correct.

I just went and checked to see if you could enable the time-based condition using the generator start/stop assistant in the MP to skip the Cerbo connection (figuring you're probably gonna set it once and leave it alone). Unfortunately there's no time-based condition in the assistant, so you would have to use the Cerbo for that (or the smart switch as @groot59 suggested).

Click to expand...

just in case I've missed something, I've attached screen shots of all the settings I changed when trying to get the Generator Start/Stop function to work from the Cerbo....maybe I've done something wrong?

Ruburnel said:

just in case I've missed something, I've attached screen shots of all the settings I changed when trying to get the Generator Start/Stop function to work from the Cerbo....maybe I've done something wrong?

Click to expand...

The first image doesn't really matter whether you set to generator or grid. Mine's still grid.

The remaining images look correct.

Did you make the necessary changes in VE Config (add relay assistants) as well as wire the connection between the Cerbo Relay 1 and the MultiPlus?

Adam De Lay said:

The first image doesn't really matter whether you set to generator or grid. Mine's still grid.

The remaining images look correct.

Did you make the necessary changes in VE Config (add relay assistants) as well as wire the connection between the Cerbo Relay 1 and the MultiPlus?

Click to expand...

Ah, I thought this could be done without the "hard wiring" from the Cerbo to the Multi i.e. just in the software (seeing as I wouldn't want to change it very often, if at all)......my bad
I think the "timer switch" is the easier option for now and it should be with me tomorrow sometime, so I can install it and let you know how I get on

Ruburnel said:

Ah, I thought this could be done without the "hard wiring" from the Cerbo to the Multi i.e. just in the software (seeing as I wouldn't want to change it very often, if at all)......my bad
I think the "timer switch" is the easier option for now and it should be with me tomorrow sometime, so I can install it and let you know how I get on

Click to expand...

Yeah, to make this work you do have to run a wire between the two devices. There is a Generator Start/Stop Assistant, but as I stated earlier, it doesn't allow for setting a timeframe condition.

The timer does sound much simpler for you.

groot59 said:

I just use a smart switch to power a contactor that turns grid power on. Might be a crude, brute force approach, but this has been working flawlessly for 18months on my 4 x Multiplus 24/3000 inverter split phase system. I turn power on to charge during off-peak hours and run all my major loads on-peak off the batteries.

Click to expand...

I've installed and tested the smart switch and all seems well Presumably, once the battery is "full", the MultiPlus will stop trying to charge it or the BMS will stop accepting any more charge?

Ruburnel said:

I've installed and tested the smart switch and all seems well Presumably, once the battery is "full", the MultiPlus will stop trying to charge it or the BMS will stop accepting any more charge?

Click to expand...

Kinda both. It all depends on the settings programmed into both the MP and the BMS. If your MP settings are higher than the max voltage the BMS allows, the bms "should" stop charging. The MP will stop charging once the batteries reach the set voltage in VE Config.