I love that idea of using a small inverter on the main bank to power critical loads, allowing the main inverter to shut off at a higher SOC, but the critical loads can stay on until the battery reaches a lower state.
Regarding the Multiplus on the Smart Load output of the Sol-Ark, the problem I see with that is the PV is already undersized, and if the SOC doesn't reach the Smart Load threshold routinely, it's just going to deplete the critical backup batteries and potentially shut down the critical loads even though the main inverter and batteries are still on. That's kind of the opposite of the way I need it to work in that respect. It would be great if the internal charger of the Multiplus could be controlled via dry contact. It might be something I tackle on my next side project. Right now I'm programming a LilyGO ESP32 to read the SOC from an EG4 Communication Hub and display that over time on a web page for a client. It's an oddball scenario, but I have a huge EG4 bank of LifePower4 that is open loop, and the owner just wants to see SOC via the Internet. I couldn't find a way to do it, so I decided to build it. The ESP32 gathers data via RS485, stores it locally on an SD card, then uploads it via WiFi every 30 seconds to a server where I display the data via a web page. If anyone else finds themselves in this odd predicament, let me know, and I might be able to help. Jason Szumlanski On Sat, Sep 5, 2026 at 12:41 PM Zeke Yewdall <[email protected]> wrote: > Why not put the "grid" input of the victron inverter on the smartload of > the SolArk. > > This would also mean that you're cycling the Storz batteries all the time, > as the smartload would turn off grid power to the victron when the main > batteries start draining. But if you set the cutoff for the smarload less > than typical low SOC overnight, then it would stay on during normal daily > use, and just feed power through the victron to the storz. But if you > dropped below that SOC, then the victron would become it's own off grid > system till the main ones got nearly full again... not sure if something > like that is doable with the relative loads of everything. > > Other possibillity may be to get a cerbo and node red involved and somehow > control the victron to pass through power all the time, but only turn on > charging on the victron if SOC is above a certain level on the main bank... > could be pretty complicated, not sure... I've not done a lot with the > victron ESS and added programming above defaults for simple off grid > systems. > > Something I often do (though doesn't address reusing the old storz > batteries in your case), is to put a small victron phoenix inverter on the > main 48 volt battery bank, which powers some critical loads (specifically > the internet, so I don't lose comms to the AIO if it faults). Don't know > how the pytes batteries and SolArk handles this, but with the Sol-max > batteries and AIO, it works fine... the battery measures the extra draw, > and adjusts the SOC that it reports to the AIO, even though the AIO never > directly sees that DC draw off the battery bank. > > (Jason Szumlanski) >> >> >> I have a new off-grid client with an undersized PV system, and they have >> had quite a few problems with batteries reaching low voltage disconnect >> and >> dark start issues. It was time for an upgrade. >> >> I reused their Sol-Ark 15K, upgraded them to a couple of Pytes v16, and >> added PV, but they weren't ready to give up their relatively new Storz >> batteries, so I repurposed them with a Victron Multiplus II to be a big >> UPS >> for critical loads like Internet, security cams, boat lift (yeah, it's >> critical), refrigeration, and other key loads. These are particularly >> important because the home is usually unoccupied. We need remote insight >> when the primary inverter shuts off, and this is one way to do it. >> >> But I am now questioning my judgment. I have dialed back the charge rate >> on >> the Multiplus, which is fed AC Input from the Sol-Ark. I don't need to >> charge the Storz batteries quickly when power is restored to the Sol-Ark, >> and it's more important for the primary Pytes batteries to get charged up. >> It would be great if I could limit charging on the Multiplus to when the >> Pytes are full. >> >> It's hard to go back now. I'm trying to figure out a solution. One thing >> that comes to mind is putting a chargeverter on the Sol-Ark's Smart Load >> output that would only charge these Storz batteries when the Pytes are >> full >> or nearly full. That would work, but it's an expense I wasn't planning >> for, >> and another parasitic load I don't need (the Chargeverter stays powered up >> on DC power even when there is no AC source). >> >> Has anybody else Daisy chained inverters like this, and what is your >> preferred solution? >> >> Jason Szumlanski >> Principal Solar Designer >> Florida Solar Design Group >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: < >> http://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/attachments/20260904/127dc1a2/attachment.htm >> > >> >> ------------------------------ >> >> Subject: Digest Footer >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> Pay optional member dues here: http://re-wrenches.org >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> There are two list archives for searching. 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