question

tylera avatar image
tylera asked

Isolation between battery banks on a boat

Consider the case of a boat's electrical system being designed from scratch.


There will be multiple battery banks (48V, 24V, 12V).


Shore power and solar power will charge the 48V bank.


48V->24V and 24V->12V will happen via step-down chargers. (This could be an MPPT or an Orion).


Should the step-down chargers be isolated or not? Why?


I've seen lots of answers like "if your systems have a common ground than it doesn't matter." or "If you want to keep the ground separate than use isolation", but what I'm curious is: why would you choose to design one way or the other? (Yes, we can assume galvanic isolation for shore power.)

MPPT SmartSolarorion-tr smartmarineisolation
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kevgermany avatar image
kevgermany answered ·

This forum isn't really for design issues.

But... It's relative. If you don't have a common ground each part of the system can and will be at a different relative voltage. Non-isolated converters will force a common ground. There's also the potential for earth loops etc.

Most installations don't need isolated units.

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tylera avatar image tylera commented ·
Have a citation for the purpose of this forum?
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