question

rehret avatar image
rehret asked

Using B2B to charge while motor is running

Hello all,

my current setup consists of my starter batter(AGM)->Orion-Tr Smart 12/12-18A->Lithium Battery

The Lithium Battery also gets charged by a Solar panel mounted on the roof connected to an MPPT.

My thought was using the excess solar power to charge the starter so that the smart alternator would not need to provide 100% of the power for onBoard electronics.

In the B2B, I could define the appropriate voltages. Is the alternator protected against counter currents? Will the alternator deactivate at all? Or is this a viable approach to reduce power consumption (of the motor from the alternator)?

Any advice is welcome,

Best,

R

orion-tr smartSolar Panelalternator
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3 Answers
mvas avatar image
mvas answered ·

No, you cannot do that.

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Kevin Windrem avatar image
Kevin Windrem answered ·

A second B2B charger with input from the lithium and output to the AGM would work but take care to insure both of the two B2B chargers are NOT active at the same time.

I don't know of any way to detect "excess" solar panel output for the Lithium > AGM B2B activation.

There are non-Victron bidirectional DC-DC chargers but you'd still need the logic to control charge direction.

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rehret avatar image
rehret answered ·

Thank you both! I would repurpose the B2B to only charge the starter, as i am sure i wont need starter to lithium charging in the future, and if so, i could rewire on the road within a couple of minutes.

The Excess Solar Power will be determined, manually, if the lithium battery is full, i will deactivate its charging option and would activate MPPT->B2b->Starter Charging.

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