Hey, I recently upgrade my SmartSolar 100/20 to a 150/35 (increased my pv) which doesn’t include a load output like the former.
On my BMV-700, I can set the programmable relay to disable my 24/800 inverter on low SOC, but how do I deal with the DC side? It wasn’t an issue before due to the load output on the charger, but now those dc loads are connected via the BMV shunt.
My model is : Phoenix Inverter 24/800 120V VE.Direct NEMA 5-15R (PIN241800500)
Regarding the relay, it’s already wired to the remote port on the inverter. I’m not really concerned about it cause I can shut it down remotely during the darkest days of Washington State.
What I’m concerned about is my DC devices that don’t run off of an inverter. I’ve specifically set the system up like that so I can shutdown my inverter without killing my mobile hotspot and PI3+ running Venus.
Is your concern maintaining the DC loads while the inverter is shut down? If so, there should be no problem.
The programmable relay does nothing to the current flowing through the shunt. The DC loads will continue to draw power, no matter the state of the relay.
Normally you would use a Smart Battery Protect (as already mentioned) to disconnect loads upon low voltage.
However you could always use your existing 100-20 mppt as a low voltage cutout for your other DC loads.
IF the low voltage setpoints can be set, mppt and the load current is suitable, AND the mppt self consumption is within your tolerances.
Device self consumption is an evil that has to be factored in.
As devices will eventually totally deplete your battery until it disconnects, or is destroyed.
Batteries that disconnect due to low voltage are still due vulnerable to their own self discharge.