Off-Grid Solar Design, Education and Advice

June 29, 2026 1:28 pm

I've spoken before about inverters and generators below a certain price point: they produce 60V + 60V instead of the expected 120V. Before the recent inverter upgrade my home was operating from that ... View More

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Michael Blankenship

April 19, 2026 8:56 pm

I've created new Python scripts which I can now run on my MacBook to watch what's going on with my solar system. It gives me quite a bit of insight and control over things at my home. * ChargerOff.py... View More

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Michael Blankenship

April 19, 2026 4:48 pm

A big upgrade to my off-grid solar setup today: I upgraded my inverter from the Victron Phoenix 1200W 24V to a huge Victron 24V Multiplus-II 3000W Inverter (with charger feature). The previously-requi... View MoreA big upgrade to my off-grid solar setup today: I upgraded my inverter from the Victron Phoenix 1200W 24V to a huge Victron 24V Multiplus-II 3000W Inverter (with charger feature). The previously-required Bluetooth upgrade dongle got retired. I'm reusing the same set of four 6V marine, lead-acid, deep-cycle batteries as before in series. The earlier setup involved much smaller wiring throughout. The bigger inverter and wiring to my house can now accommodate the larger values. I had to dig a trench and install 10-2 Romex to support the 25A (plus a little more) coming out of the inverter at the maximum output. I had to upgrade the fuse sizes in the premise switch inside the house. I had to upgrade the sizing of the wire between that switch and the circuit breaker box. I had to install the "binding screw" in that panel now that the new inverter provides 120V on just the black wire (the lower-cost Victron provided 60V on black and 60V on white so you can't bind 60V white to ground = very bad). The system is much safer as a result, a tripped circuit breaker before this would have resulted in 60V still being on the return side of all outlets (not very safe). I added a big red wire to connect the breaker box's first hot leg to the second: I don't anticipate ever doing 240VAC in the box so I thought I'd enable the second set of breaker slots for future expansion. The wiring is pretty mondo from the batteries to the inverter, 0/2 gauge. And I upgraded the wiring between the batteries in series as well as the ground side which goes to the BMS shunt. As before, there's a "big black switch" on the ground side of the batteries. The inverter output now has a "big red switch" as well as a large-value inline fuse. I retired the previous Busmann series circuit breaker. I added both temperature and voltage sensors which now connect to the inverter. I added smart connectivity from the new inverter to the existing VenusOS Raspberry Pi computer so that it can manage it as well. It's a dongle with a USB connection. In theory, I can now do some monitoring of the battery temperature in the solar shed in case I need to add the foam insulation back in the winter. I now have programmatic access to the power load on the consumption side of things. I used this as an opportunity to check the fluid levels on all the batteries. They're looking good since they're fairly new.

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Michael Blankenship

The new courtesy outlet has cleaned up the power for wifi/Internet & security systems.

April 19, 2026

Michael Blankenship

Here’s that HomeLine circuit breaker box.

April 19, 2026

Michael Blankenship

To protect the electronics in the shed I added a new UPS. That’s cleaned up the three power strips from before.

April 19, 2026

Michael Blankenship

March 21, 2026 5:19 pm

I've just installed Node-Red to my VenusOS Raspberry Pi. It's a user-friendly programming platform for doing a variety of workflows as scheduled on the Pi itself. I'm researching what can be accomplis... View More

Homepage [Forecast.Solar]

forecast.solar

Restful API for solar production forecast data and weather forecast data based on your location, the declination and orientation of your solar panels.

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Michael Blankenship

https://www.victronenergy.com/live/_media/venus-os:node-red_flow_editor.png

March 21, 2026

Michael Blankenship shared a photo

December 30, 2024 6:06 pm

I setup a Raspberry Pi computer which connects directly to my Victron charge controller and which runs a copy of something called VenusOS. From what I understand this is the software that runs on one ... View More

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Michael Blankenship

And here's the script called in line 7 that's responsible for returning the wattage.

December 30, 2024

Michael Blankenship

This is the Terminal screen where it's been running most of the day. The benefit is that I might want to turn on the crockpot later in the morning after the system is producing sufficient power (but not before).

December 30, 2024

Michael Blankenship

As of today I have completely reinstalled VenusOS v3.67 on that Raspberry Pi computer and it's now back in service (after a power outage months ago took it out of commission).

March 18, 2026

Michael Blankenship

March 18, 2026 4:47 pm

Finally. I had an outage of that cool add-on device that I put into my solar setup. It's a Raspberry Pi—based computer which directly connects to one of the blue Victron boxes. It allows an incredibl... View More

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Michael Blankenship

https://www.victronenergy.com/live/venus-os:large

Venus OS Large image: Signal K and Node-RED [Victron Energy] www.victronenergy.com

March 18, 2026