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bradley-thompson avatar image
bradley-thompson asked

Using Smart Battery Protect SBP 100 as PV disconnect - where to place the SBP in the circuit?

Long story short..

I have an SBP100 that I want to use to switch on/off my rooftop solar system. It would be switched off when connected to shorepower or a generator, etc. I'll basically be using it as a remote relay switch with low voltage cable run to a panel switch elsewhere. I know the SBP is way overkill for this but I already own it so..

Should I put the SBP in between the panels and the MPPT or between the MPPT and battery? Logic says I should put them between the panels and MPPT so that the MPPT doesn't see any power it can't deliver to the battery. However, I'm concerned that the SBP will not be able to activate without sunlight hitting the panels (let's say I want to activate the panels at night so that they start charging in the morning). If I put the SBP after the MPPT, then in theory it should work as I want it to but I'm concerned that the MPPT will receive a bunch of energy from the PV at all times that it can't dispatch. Is that harmful?

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2 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

Generally a bad idea to use the SBP to do this. Yes, the control needs to go between the MPPT and the PV, so as it doesn't lose the battery reference. The PV voltage would likely damage the SBP, it would be far better just to use a suitable relay to do the job. You could also use the remote input of the MPPT to control this also.

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bradley-thompson avatar image bradley-thompson commented ·

That's what I was afraid of. I've ordered an automotive relay that hopefully will work. It will be fun to experiment with either way.

I would use the VE.Direct port but will lose communication with my Venus system. I suppose I could use the Bluetooth connection to power it on and off but where's the fun in that..

I'll save the SBP for a future Multiplus install.

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Michelle Konzack avatar image
Michelle Konzack answered ·

Shore power is expensive, hence the question:


WHY the heck you want to disconnect the Solarpanels?


The MPPTs have a remote control, why not use this to prevent charging?

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