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rgsailor avatar image
rgsailor asked

What is the best way to connect a victron mppt 100/30 to house and starter batteries?

Hi,

I want to charge 2 different batteries (house 12v 200ah and starter 12v 55ah) with a victron mppt 100/30.

I have also purchased a Victron BMV712 to monitor both batteries. The BMV712 came with a great diagram for the connection.

I would like to get a good understanding of the best way to connect the Victron MPPT to charge both batteries.


What is the best way to connect the Victron MPPT 100/30 to house and starter batteries?


Thanks,

Rob

MPPT Controllersbattery charging
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4 Answers
christyler avatar image
christyler answered ·

Just use a cyrix, between the two batteries

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zuzullo avatar image zuzullo commented ·

Yes, isnt the cyrix the easier and cheaper way?

And the MPPT goes to the house battery.

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mplnck avatar image
mplnck answered ·

Hey,

depending on the type of battery (lead, AGM, LipoFe etc.) you need to take a manual relay.

I had a AGM 202Ah 12V and a lead 90Ah 12V connected with a cyrix properly and it didn't work because of the difference in the loading voltages.

Just use a normal 12V relais with a normal switch. Take care of the right copper diameter.

Cheers Mario

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rgsailor avatar image rgsailor commented ·

Thanks for the reply. My house battery is an AGM 200ah and my starter battery is an AGM 55ah.

Would the cyrix work in this case?

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Paul B avatar image
Paul B answered ·

yes it would work fine

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r2d2wat avatar image
r2d2wat answered ·

If your house and start battery have similar charge parameters, a simple solution is to add a voltage sensitive relay (VSR). Set it up so all your charging sources charge the house bank. Then when the house bank starts to get full (increased voltage), the VSR circuit opens to charge the start battery. Then whatever charge source fills your house bank, your start battery will be charged. Shorepower, engine, solar...

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boekel avatar image boekel ♦ commented ·

You can even use a simple diode-splitter block, and set all voltages 0,6V higher to compensate for the voltage drop over the diode.

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