I have a smaller DIY camper system install running for 3 years now. Still trying to find a way to maximize solar consumption for the times we are connected to grid and paying for power. It works well for our needs.
-Cerbo GX
-MultiPlus-II 12/3000/120-50 120/240V
-SmartSolar MPPT VE.Can 150/100
-SmartShunt 500A
-Lynx distributor
-5x 100AH Battle Born Batteries
I’m seeing the request to maximize solar over grid power often and many of the installs are RVs and boats which are specifically prohibited from using ESS.
The recent addition to prioritize alternate charging sources for DC loads doesn’t help for AC loads.
Please Victron split out ESS functionality so that solar can have priority over the grid for mobile apps or qualify ESS for use with mobile apps as long as the grid code is set to none to prevent grid feed-in.
You can use a relay on the GX and the AC ignore function of the Multiplus to make the shore power behave like a generator.
This would maximise solar generation but also allow you to automatically or manually connect shore power to recharge batteries or supply loads beyond what the Multi can.
Question from a Home-System-Guy:
Why can’t the System simply be run in ESS Mode? Connecting / Disconnecting Shore Power wouldn’t be much difference to a grid loss at home, I assume?
Sure, it would automatically priorize bat usage over grid, but that’s what desired, isn’t it?
Forced charging could occur through charging schedules?
Or are there sustainable features that do not work along with ESS?
There is always a short moment where the shore plug will be live. It is therefore a safety issue.
The challenge that I have run into with my smaller system is I can easily overload it and need to be able to accept AC base on power demand. In my previous attempts to use The Ignore AC Virtual Switch the Multiplus II only monitors the AC load on L1. If high draw loads are on L2 it can overload the system. I have looked at using generator start stop but not sure if that would see the total load of the system since it is run from the Cerbo?
I’m sure it does see the whole load and easy to test. Just enable one relay as Generator Start/Stop then set the load conditions. Apply your test load and see if Cerbo engages the relay, don’t need to have it actually connected to anything.
I had used ESS in my RV for quite some time, but I also have dual backfeed prevention devices. The reason I stopped is because ESS never played nicely with my generator. (I got tired of reconfiguring the multi’s every time I was travelling or plugging into shore power) Even with the ac source set to generator the MP2 would still “pol” the ac input every so many seconds, which resulted in constant fluctuation of the ac. Not good for the generator or some of the ac components connected to the system. My little Honda doesn’t seem to care but the big Kubota does not like it. I was under the impression that when the AC source was set to “generator” that the MP2 behavior would be changed to normal (disabled ESS) but that doesn’t seem to be the case.
I know not exactly relevant to the OP, but something to keep in mind for those that may decide to experiment.
With a Quattro based system where the Generator is on its own AC input, you can disable LOM detection for just that input and it works great.
I have tried with LOM disabled and it still doesn’t play well. I know it’s something to do with the ESS because the generator is smooth with ESS disabled. I think victron still needs to do a little work on this but I don’t see that happening.
I set up start stop on the Cerbo and test loads on L1 and L2 and it work to indicate the Generator (connect to AC) worked. Now just need to wire to the multi plus and configure. Thanks! been lo0oking for a solution like this for a couple years.
