How to wire AC side of Victron Multiplus

[Tia Bu]

Thinking of doing LifePO4 conversion. We often charge our batteries while cruising using our 5.5KW generator and 40 amp Charles charger. That charger has a lithium setting, so we could continue using it, but it seems so darn slow in the new lithium world!

After much searching, it seems a Victron Multiplus might be the fastest and most economical charger for a new 400ah 12v lithium bank? It seems to have a "charge only" switch, so I could use it that way.

But the inverter function seems nice. Trouble is, I can't conceptualize how to wire it into my current AC panel.

I have two 30 amp shore power inputs. And I have the 5.5 kw generator input (50 amp.) My panel allows me to switch between shore power and the generator. But it prevents both inputs being open at the same time.

I suppose I could wire the Victron in the line between the generator and the panel. That would let me charge the batteries when the generator is running. When the generator is off, and we're away from shore power, the inverter would power the AC panel, as long as we have the panel "generator" switch on.

But that would mean we'd have no charger available when we're on shore power, right?

Is that even a big deal with lithium? We would have solar to keep the batteries topped off at the dock.

Is there another way to wire this up that would make more sense?

[smac999]

Inverter chargers are not simple to wire correctly. and even harder if you nave 2 shore lines going to a single shore / gen transfer switch. As only one shore line can go through the multiplus and the 2 shore netreals must stay separated on board. As well as the inverter output neutral. .

I would suggest having someone come to the boat and make a plan for you. As it will vary greatly with exactly what you have existing.

The multi needs to go after the switch so both charge. Otherwise it would be silly.

[rslifkin]

You can always make a sub panel. So the existing sources feed the main panel for anything you don't want powered through the inverter. This will also feed to the inverter input. Then the inverter output powers the new sub panel and whatever loads you connect to it. The inverter has a built in transfer switch so when shore or generator power is available to the input it will be passed through to the output (even in charger only mode). In "on" mode it will pass through and charge, but when the input power is removed it will switch to powering the output side from the inverter.

[s/v Jedi]

Originally Posted by Tia Bu

Thinking of doing LifePO4 conversion. We often charge our batteries while cruising using our 5.5KW generator and 40 amp Charles charger. That charger has a lithium setting, so we could continue using it, but it seems so darn slow in the new lithium world!

After much searching, it seems a Victron Multiplus might be the fastest and most economical charger for a new 400ah 12v lithium bank? It seems to have a "charge only" switch, so I could use it that way.

But the inverter function seems nice. Trouble is, I can't conceptualize how to wire it into my current AC panel.

I have two 30 amp shore power inputs. And I have the 5.5 kw generator input (50 amp.) My panel allows me to switch between shore power and the generator. But it prevents both inputs being open at the same time.

I suppose I could wire the Victron in the line between the generator and the panel. That would let me charge the batteries when the generator is running. When the generator is off, and we're away from shore power, the inverter would power the AC panel, as long as we have the panel "generator" switch on.

But that would mean we'd have no charger available when we're on shore power, right?

Is that even a big deal with lithium? We would have solar to keep the batteries topped off at the dock.

Is there another way to wire this up that would make more sense?

Of course. Why two shore power cords? Is one for A/C ?

[Tia Bu]

It came that way. I think originally the two AC units needed two shore power cords. But with new AC units, you can run the boat fine at the dock with just one 30 amp cord.

[Tia Bu]

You can parallel the two AC buses with the current panel. I always parallel them if running the generator. And parallel them if at a dock with one 30 amp connection.