After reading the Multiplus manual I seem to understand that there is no way to use the grid input to top-up the batteries without the system changing from off-grid to grid mode.
In other words, if my understanding is correct, one cannot charge the batteries from an alternative source while running in off-grid mode.
Or is there a way to do so?
In order to draw energy from the grid, the input relay must close, right? The energy should enter somewhere…
And when closing, it will be a grid connected device. No matter that it’s the real grid or a generator.
If you don’t want the MP2 to see the grid, use an additional charger.
Thanks, that is what I was going to do if nothing else was feasible, I thought perhaps the “charge only” mode had a setting allowing this to be done.
I’m surprised Vicron did not cater for this situation, someone might be off-grid and have a small genny but still good enough to replace the PV in poor lighting. All it takes is another relay to allow (or not) for the current flow to be directed to output but still have it available for the charger. I suppose the next best thing would be the “grid assist” mode but that will only draw power if the shore isn’t sufficient I believe whereas it should be the exact oposite
Charger only mode prevents the Multi from operating as an inverter if the grid fails.
Inverter only mode ignores the grid completely so the load always runs off battery and there is no charging option.
There is no mode to allow AC pass thru without charging the batteries but in the Multi configuration (Victron Connect or veconfig) you can disable the charger function completely. There is no way to change this setting from the GX device however.
2 Likes
It’s a real shame, I don’t really want to purchase a third bulky MP2 only because in a very unlikely situation I need to charge the batteries with perhaps only 30A or even less.
I guess I’ll have to resort to using a non-Victron component on this occasion.
- List item
The MultiPlus, MultiPlus-II and Quattro devices can only do one single conversion AC-to-DC or DC-to-AC, but not both at the same time.
They have only one bidirectional AC-DC converter that can function as an inverter DC-to-AC or as a charger AC-to-DC but not both at the same time.
So if you connect the grid and want to charge the batteries (AC-to-DC), you can’t have AC output from battery (DC-to-AC) at the same time. The output must be from the grid when charging.
ESS does the exact opposite of the “grid assist”.