Had a bit of a stressful night, as the temps had went down to an unseasonable 25 degrees F on the last day of Oct. We usually only get our first frost the first week of Nov, and I wasn't sure how warm the inside of the solar shed would stay overnight.

The only real concern was, the 24v system is composed of base model AmpereTime/LiTime batteries, without low temp protection, much less self heating. I was worried they would get to or below freezing, and not warm up before the sun hit the solar modules and the Renogy tried to charge them, which could brick them. Luckily, while the outside temp got to about 25, the inside temps never got below 40. enough insulation and thermal mass to keep it up enough.

Tonight it's supposed to be below freezing again, but not as low, plus I've been able to switch over from the AmpereTimes, to the EG4 stack, which has low temp protection built in.

The main thing keeping me from switching over was, charging the 48v stack of batteries.

The EG4 3K all in one can charge from AC or DC, however I don't have AC incoming at the moment (eventually plan on being able to use the genny for that), and while it can accept up to 500vdc on the pv input, it requires a minimum of 120vdc just to trigger the dc charger. In perfect conditions, I might be able to reach this, for maybe an hour a day. Not going to work.

2nd choice, is a Victron 100/20 charger I have. It can accept up to 100vdc which is fine, but it needs about 5v above the charging voltage to start. Since a "48v" system is actually a 51.2vdc battery, and charges at about 56.2vdc, I need at least that much or more from the panels. I can do that with 3 panels in series. This would give more more time in the day at that voltage, though not near all the "daylight" hours, simply because of the trees at the present. With 3s2p, it might be usable.

3rd option is using a Renogy boost controller which can take 12vdc to 40vdc and boost it up to the charge current for a 48v. With only 2 panels in series, this could give me 2s2p or 2s3p and also may be usable.

I'm going to try option 3 for a few days, see how it works, and then maybe do option 2 and compare.

There is a 4th option I'm looking into. A microinverter on each panel (or 2s connection of panels), have that converted at the panel to 120vac 60hz and bring that into the AC input of the EG4 3k all in one. This might give me the best mitigation of shading, though it would be a few hundred more dollars at the moment. The main holdup on this option is, it seems the microinverter match the voltage and frequency of the AC line they are connected to. I need to see if there is any AC voltage on the AC in on the EG4, with nothing connected. If it's uncharged, the microinverter may not be able to sense anything to try to match. Anyone want to sponsor a couple microinverters to try this out?

In any event, I'm at least using the full stack of batteries, charging them (a bit) and making use of that power.

I still need to connect the ground rod I drove today (3/8" x 8'), get the 30amp cable in and connected to the RV and more bits and bobs. oh well, progress is progress and take it when I can get it.