question

cptcrunchie avatar image
cptcrunchie asked

12v to 24v conversion info needed

I just completely electrically repowered our 46' sailboat. Solar, external Balmar MC-614 alternator, 900Ah 12v AGM battery bank, 3 - 100/30 Victron SmartSolar MPPTs, a 12v/3000/120-50 MultiPlus, etc.
In tremendous hindsight, I'm now thinking I should have changed my system to 24v instead of 12v. I understand the physical connections I need to make to the battery bank, and adding the 24v to 12v converters for the electronics and some utilities, but can anyone tell me if it is still possible with what I have, or would I need to change out everything, especially the MultiPlus?
I ask because, in that moment of clarity, I would have decreased the size and cost of all the wiring, it would be more energy efficient, all my PMDC motors - windlass, pot puller, electric winches, and a soon to be added bow thruster - would work much better at that higher voltage.
MultiPlus Quattro Inverter Charger
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2 Answers
wkirby avatar image
wkirby answered ·

The MultiPlus needs to be replaced with a 24V version. The MPPT charge controllers will be fine and can remain.

Perhaps your 12V 900Ah battery bank can be reconfigured to be 24V 450Ah depending upon the composition of the bank

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justmurph answered ·

Given that you’ve already done the work, I wouldn‘t be changing it now. Going 24V will let you run smaller wiring and increase efficiency to some small degree, but it also adds complexity, decreases efficiency every time you’re converting from one voltage to another and will also decrease reliability (because you now rely on those DC-DC converters). Also keep in mind the costs of swapping motors and switch gear on things like winches adds up very quickly.


All of that said, no regrets here converting my sail boat to 24V. I went 24V so that I could run my dive compressor off my inverter and solar (2.6kW load). I’ve also swapped my windlass and winches to 24V. They’re a hell of a lot stronger now, but the cost was obscene. In hind sight I would have just pulled the 12v motors off my winches and gone manual.

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