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zuco avatar image
zuco asked

Replacing Schaudt LR1218 with SmartSolar MPPT 75/15

I have a motorhome with dual AGM batteries plus starterbattery and existing solar panel with an Schaudt LR 1218. The leisure batteries are conneted in parallell.


The Schaudt have the following 5 connectors in use,

- Solarmodule (plus/minus)

- Starterbatterie (plus)

- Whonraum Batterie (plus)

- Batterie (minus)


I want to replace the Schuadt with the SmartSolar /5/15, however the connections does not fully match up. How should I connect the 75/15?

- the connectors for the solar panel are obvious - not an issue

- the other connectors does not correspond connector to connector with the SmartSolar and I'd like to see a diagram/instruction for this use case. Any tips on where I can find that?


Best Regards,


.m.


MPPT Controllers
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3 Answers
johanndo avatar image
johanndo answered ·

You cannot replace it by a Victron MPPT directly. The Schaudt has 2 independent charge outputs for 2 batteries and it is a PWM controller, the Victron controller is a MPPT controller, it needs higher input voltage (you may need different panels or wire your panels differently to have at least 5V higher voltage on the solar input side than the battery voltage) and charges only one battery.

You can use a relay to divert the charge current to your start battery, use a voltage sensitive relay to do it automatically or use a DCDC charger, to charge your start battery from the house battery.

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ric-dal avatar image
ric-dal answered ·

Hi Johanndo for your explanation. We have exactly the same issue and need to charge the van battery when not in use.
When the leisure batteries are fully charged I want to then charge the van battery.
Would I be correct using the Cyrix Battery combiner is the correct method that kicks in the Automotive IP65 charger?
I have also seen the Battery Master is this not a simpler option ?
Interested in your thoughts

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zuco avatar image
zuco answered ·

Thanks for the quick response.

So I need to add a DC/DC charger to complete the setup.

Is there any sizing guide for DC/DC chargers and schematics for a setup as the one I'm looking for?


Best Regards,


.m.

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