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tom4x asked

Feeding camper's excess PV power into house installation (12V vs 48V)

Hi,

Background: We have a Campingvan with Solar Panels on it, a 12V system. In our house, we have a MPII setup with 48V batteries. Can we easily use the excess PV power of the camper - which gets lost when the camper is just standing still - in our house's installation, with minimal effort?

In the Camping van we have

  • Victron MPPT 150/35
  • 12V system
  • 2 panels connected in parallel (Umpp=30V with Impp = 9A)
  • a "dumb" inverter of a different brand
  • BMV, Orion, ...

In the house we have:

  • A MultiPlus-II setup
  • 48V batteries
  • EM24, Cerbo GX, ...

Just connecting the camper's Inverter

Using a 12V to 48V charger won't work either, as it should only draw the excess energy off the PV and not drain the batteries, i.e. it must communicate with the MPPT.

Is there an easy way to solve this?

MPPT Controllers
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seb71 avatar image seb71 commented ·

Don't bother with this.

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hardy-tuner avatar image
hardy-tuner answered ·

Which kind of Panels and how there are connected to each other?

Difficult to do without Problems or compromises.

First option: unplug PV at van and plug at additional mppt at House, but U lose healty Charging for 12v batteries.

Second Option like u said: 12 to 48v Could be possible when bmv-712 is starting and stopping by SoC off the 12v system via additional Relais. But also to think about distance and voltage drop when starts in van and reach the house.

Third Option: using micro grid tie inverter, feeding in directly into house grid.

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tom4x avatar image tom4x commented ·

Re info on panels: Right, I added that above.

Already thought about rewiring the panels as well (serially to achieve > 60V, just enough to start charging), but that wears out the MC4-connectors, I guess?

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kevgermany avatar image kevgermany ♦♦ tom4x commented ·
They're not designed for this and must not be disconnected or connected under load. You should balance cost/inconvenience against savings. With the small PV from a campervan, it's not likely to be worthwhile.
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