question

kcmcconnell avatar image
kcmcconnell asked

Victron Phoenix Inverter (800/12) to feed a MultiPlus (12/2000/80)?

I have a Victron Phoenix Inverter (800/12) setup in my Sprinter van under the passenger seat. This inverter was originally setup to supply power to a 700watt hot water heater or to a Victron MultiPlus (12/2000/80). The switch to direct the power had not been working so I replaced it recently (hadn't needed it because my solar panels supplied all the power I needed). With that said, I went ahead and replaced the power switch that controls where the power is sent. Once this was done, when I switch to send the power to the MultiPlus, it overloads the Phoenix inverter.

Now for the question. Is it possible to limit the Phoenix inverter to a maximum number of watts so that it does not hit the overload (700watts maybe) or can I limit the MultiPlus to only draw ~700watts (from the grid/phoenix inverter) for charging?

Thanks in advance.

MultiPlus Quattro Inverter ChargerPhoenix Inverter
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
Mike Dorsett avatar image
Mike Dorsett answered ·

Yes you can use VE configure to limit the multiplus charging rate. However, would it not be more efficient to use a dc/dc converter for charging the second set of batteries?

2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Vance Mitchell avatar image Vance Mitchell commented ·
From a few experiments it is 5-10% more efficient to use a dc-dc charger.

However using cascaded inverters also allows for larger loads than the single inverter could provide(using power assist), It also allows more flexibility in linking seperate systems with different voltage options.

Another bonus is the possibility of reducing cable loss in systems where the distance between battery banks becomes an issue.

My recommendation would be to set the input limit to around 75-80% of the rated output of the first inverter. This helps keep temperatures under control.

If possible setting it lower (30-50%) would theoretically increase efficiency.

0 Likes 0 ·
kcmcconnell avatar image kcmcconnell Vance Mitchell commented ·

When building the van I had initially thought about a DC-DC charger, but decided against it due to the fact I also wanted an option to power the water heater and that the wiring required to send the DC power to the back of the van was going to need to be much larger than the 12g I'm using to send 120v back there. I'll check the MultiPlus again, but I think the lowest setting for it was 7.5A, which is still too high. (800watts is 6.67A if my math is correct).

0 Likes 0 ·