Hi to all
My basic system comprises of the following
Venus GX (connected to LAN internet)
Win 10 PC with VConnect v6.17 and VRM setup
MP II 48/5000
EVE LiFePO4 280Ah x16
JK-BMS B2A24S300P
SS MPPT 85A - 200W PV x28
All off-grid.
Everything is working fine with the above and this small system only gets used overnight from 22.00 to 08.00 hrs then the LFP battery recharges from solar during the day. I could do with more charging and I have a much larger system in the same building that has surplus 230V available most afternoons. I am thinking to use the Multi 70A charger to help charge the LFP battery from the larger system and wonder what the easiest way is to automate this process.
I require the MP to invert only from 22.00 to 08.00 hrs.
I then require the MP to help the solar charge the LFP battery whenever AC 230V is present at the AC input but with a couple caveats. a) only between 08.00 & 22.00 hrs when it is NOT inverting. b) Does not pass AC through to the loads, only charger mode.
Sounds fairly simple, TBH I am slightly overwhelmed with all the possible combinations but just looking for the simplest approach using relays, assistants, etc.
Any guidance much appreciated
I do something similar with a double off-grid system. I just use tasmota-plug that powers a charger to give extra charge to the 2nd system. I control that plug using Node-Red. Do you have Node-Red programming skills? It is fairly straightforward to use MQTT to collect all data (P1 port data, battery SOC info and so on). And write a function to descide based on the conditions.
I think it’s a good idea to use a separate charger on my smaller system rather than the MP2. It’s quite complicated to have it only charge (and not passthru) between certain hours and then only invert at other times.
I have wired in a simple relay to the remote control terminals of the MP2 which is controlled by a simple smart plug timer, on at 22.00, off at 08.00. I can make changes remotely to the timer using my phone which is convenient for when Winter comes and the daylight gets shorter & shorter.
I have ordered a 30A charger which will work from the ACout2 of the larger 8KW system but only when SOC is >99%. This already heats my hot water tank which is only 1.5 KW so another 2KW should be fine.
You better use a service like openweathermap in Node-Red. It will give you cloud information on your exact location, live fron sattelites… In node red you can use the aux relais from the MP2 aswell. You can even read and control most parameters/states from connected victron gear. Node-Red is powerfull. Well worth the effort. I can help you with some basics. Maby over a windows quick assist session.
The other way is to use the generator start stop on the GX. If you aren’t already doing so.
Wire the gx relay signal to the aux or temp sensor input - program that to drive the primary relay)
Then timers and low soc connect etc can be set from the GX as you want and when you want.