has dc system does not make sense

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Trond Hindenes asked Jun 22, '23

has dc system does not make sense

I have a very simple setup: Smartshunt keeps track of my Lithium bank, and a single MPPT charger for PV. In addition my motor alternator may also charge when activated.

Here's my question:
In my current situation the alternator isn't running, and there's no power from solar panels. If I have the "Has DC system" active, it shows 60W of "DC Power". I struggle to understand what this means. There's nothing charging the batteries right now, why would there be a difference between battery load and "DC Power" load?

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Answer 1 · 2023-06-22T22:17:37Z

Kevin Windrem answered · Jun 22, 2023 at 10:17 PM

I'd agree this does not make sense if you don't have an inverter. The value shown in DC Power is the difference calculated when all KNOWN sources and loads are combined. What the diagram is saying is there is 120 watts unaccounted for.

Note that the DC Power calculation can show wide variations if loads and charging sources are changing because the values don't necessarily chang in sync.

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