The original charge controller is still there, it is a Trace charge controller, it is the small white box with the black heat dispursing fins on top. My inverter has 2 inputs for solar panels, and will take 2kW of panels into each input. I dont have much roof space, so when I first installed I put 24 Astropower brand 12V, 120watt panels ( connected in groups of 4, obviously to get 48V) on the roof. Those are all still there, although giving out less power, and still go into that old Trace C40 PWM charge controller. About 15 years ago when I had the house reroofed, I had to take all panels off and put back on, At that point I added 3 panels and a charge controller onto the other inverter input ( Evergreen 210's, so about 500Watts (derated) total, 1/4 of the capacity of the inverter input). The thought was that this would make up somewhat for the lessening of power output on the other string and make up for peoples increasing electronics power usage indoors. Anyways, those 3 solar panels are the only ones going into the Outback MPPT charge controller. And right now, that is disconnected as last years storms ripped off a cable up on the roof, and it is not connected back yet ( just try and get a guy to go out on my metal roof for a small job)

So, my old charge controller is a dumb one. It doesnt need to "see" anything to let that voltage thru. If the sun is up, it presents a voltage and a potential energy at its output. I realy love that feature as when the fire happened that feature made my set up so much more robust than my neighbors. After the fire, there were no power poles or mains power for a while. My old batteries stopped working due to the power surges. The inverter and the newer Outback controller want to see power before they will work, ideally battery power would do that, unless your batteries are drained of course. Which they are if they have been trying to provide backup power for weeks on end with no sun due to thick wildfire smoke. But, my system, the C40 charge controller presents that 48V potential once the sun hits the panels. The inverter electronics and display then wake up, but the inverter and charging function is off, for safety of course. Then, you just have to walk in there and scroll the menu and hit inverter on and it all works, until the sun goes down. Get up and do it every morning and have power during the day. But, even if that were not the case, the inverter would charge set the batteries right just with mains power when it was up and then the new type charge controllers would work, correct ? I am not sure if I understand what you mean by a potential problem, do you mean if mains power is out and the batteries shut off to protect themselves as they have been discharged alot during a long storm and no sun and then the sun comes out, like we had after the long time of fire smoke ?

The new batteries, Simpli Phi 3.8 are meant as a lead acid battery substitute. My inverter was a very good one in its day. It was made in california, and hte original Trace Inverters are known for this, there are still in service all over. A neighbor 5 miles from here has an old Trace 24Volt system still running and is connected to an old Sunfrost DC refrigerator in their garage, also still running well. So, my inverter has enough setting flexibility to give these batteries the settings they want, for example, my inverter will let me set the low battery cut off voltage of 50.3V that the Simpli Phis want, where as less flexible inverters wont go that high for that setting.

The batteries that were damaged in the fire were not lead acid batteries, that is why the big fat cables were not connected. The Aqion batteries used individual thin parrallel wires to the inverter, you can see those in the phto, and their foot print each battery is 1ft by 1ft and then 3 ft tall, those old black batteries are not on a stand. But, luckily I saved those cables. A number of years ago, when my bank of 4 Trojan L16s were on their last legs, likely due to my misuse, I researched and bought what I thought should have been my "forever" batteries. I had bought Aquion batteries, 3 of them. Those are sodium Ion batteries, with carbon and maganese if I recall anyways 2 very common ores for cathode/anode. So, the Aquions should have been protected by the fuses I had in the DC disconnect box, but one of the fuses didnt blow quickly enough, and the thing about Aquion batteries is that they do not want to give very many amps at once.

It must be nice to have such a large battery bank as you have. I bet you even take care of them better than I was able to back when I had that kind !

I am just putting this into service, so we will see, I hope it all works ! Some of this is confusing to me, because, yes, I kind of do wonder sometimes how having 4 sources of potential DC voltage all connected together dont fight with each other, and somehow power ends up into the inverter. I know it works, but luckily I dont need to know how it works. It realy has been a hands off power source overall.

My battery journey : Came with 4 sealed 12V batteries, " training wheel batteries" that could never last long, but didnt need watering; Then after a short time, the real L16 batteries; then the Aquion sodium Ion ( "salt water") batteries; and now the simpliphis.

You seem to know more about solar than I do, I would love to aks you a few questions, as I put those 2 working aquions in the newly rebuilt barn, which had burned down in the fire, and at present is not connected back to any power. I should be able to have a couple panels and a minimal charge controller to charge those. But for a DC only system, isnt there some component that is a "battery saver" so that I can connect DC loads to those batteries and not over drain without having a inveterer ? I know I can easily by a 48V DC to 12V DC conversion thing to run DC lights, but I do need to protect those battereis

Here is a phot of the panels n the roof, there was a lot of deferred maintanence after the fire, all that overgrowth has just been cut by the house, and I am attempting to get the garden back.

My set up is grid tied. It doesnt have to be, but it is. Now I am confused too, as I thought it was explained to me that there had to be 2 separate banks of panels to get the full 4kW potential, I will go look. Ok, no wonder you were confused. There is only one DC input to the inverter, and everything connects together in the DC disconnect box. It was explained to me when I bought it 26 years ago that I had to have 2 separate 2kW strings if I wanted the full 4kW, which I didnt have room for with panel sizes at that time. This was such a pug and play, except for batteries, for me over the years that I realy never paid attention to the details as I didnt have to. I am now wondering if the whole 2 separate strings of panels thing was because of the charge controller limitations of the time.

When the fire happened, the power poles burnt down and melted and shorted wires, 2 locations to my backed up circuits( external office, well pump) also burned to the ground and melted those wires, so shorted them together, to the inverter backed up panel. This caused the inverter for a brief time to try and supply power ramping quickly to max power output. The inverter tried to get power from the batteries to supply that and so that blew the fuses to the batteries, one of the fuses delayed enough that the battery it was protecting was damaged. In any case, all fuses were blown to the batteries, Mains power was gone as the power poles burnt down, there was no power there. For a couple months. I could turn on the inverter in the morning due to the power from the panels thru the C40 charge controller. You are right that if it got cloudy enough, the inverter would shut down again like it was night. It never got that cloudy during that time, if it had, oh well, it would have shut down and I would need to have turned it on again..... it is not spec'd to work without batteries, it should have batteries, it just didnt at that time due to the fire and it was nice to be able to use it in a reduced capacity. Eventually, after a month, I remembered that there might be fuses and found them and bought new fuses for the batteries.

Yes, after I wrote last night, I went and looked up further, spent more time about the battery saver issue and yes also found out the C40 can be used that way too, which is nice as those are not very expensive, and undervoltage adjustable. Yes, the 2 Aquion batteries still work, so they are a battery bank. So, I am toying with the idea of having them in a small system provide lights for the barn and in the future refrigerator backup for the studio apartment I rent out. I am still running the cost numbers on that, so am looking up needed components, small refrigerators. There is a limited time to decide something as the Aquions will lose charge eventually sitting there unhooked up in the barn, it would take months at least, although it likely wouldnt hurt them much if they did. Good chance it will be too expensive -- but running new conduit and wire that far for AC power to the barn is very expensive too.

A chinese company bought out the patent/design for the Aquions, and a European company was producing under license I guess had them too for a while, I think you can get them in Australia maybe parts of Europe. The importing company, from the European manufacturer, here shut down during COVID, so dont know if that was just here or Europe to.

Alot of Aquion batteries were sold to the off grid market in Northern California, they were popular, it was shocking when they folded, but Power walls got most of the subsidies and publicity. Alot of grid tied homes are AC coupled and need some kind of battery charging/battery management and this was a definite strength of the power wall as it was all in one. Of course, the Power walls have a ton of downsides. Including lithium and cobalt, and having to connect to the internet