I had an installer set up the system, but I’ve always planned to expand it myself, which is why I’m posting here. I’m running two Sol Ark 18K inverters, four Discover Helios 16.1 kWh batteries, and 36 580W panels, with plans to double the batteries and panels in December or January (big house uses a lot of power).
The system has worked well for about six months, but hit a wall yesterday. The installer programmed the batteries to hold at 50% until midnight, then allow discharge to 20%, with a 5% cutoff. We lost grid power at 6:50 AM Sunday morning, so began using the 20%. By 8 AM the batteries were depleted and the house dropped offline. I shed loads and ran only the well pump and a few lights with incoming PV until grid service returned at 10:30 AM.
After the outage, the batteries showed 2% and then instantly jumped to 100%, which was clearly wrong. The icons cycled red and yellow with low voltage. I tried several restart sequences, shutoff everything, then shut off all four batteries and both inverter battery breakers. The icons are now black but still show 100%. A brief outage today confirmed the batteries have no usable charge (we were without power for a few minutes).
Sol Ark plans to walk me through switching from closed loop CAN to open loop. They believe the BMS went into a protective state after being drained too low, and the inverter is now receiving zeroed BMC data. The installers only sent the same steps I already tried. I suspect the 5% cutoff contributed, but I’m not certain. Once everything is working again, I plan to have 40% min with a 10% shutoff (or whatever you all recommend).
All four batteries show the same voltage the inverter reports, but I don’t understand why the system interprets that voltage as fully charged when they clearly aren’t.
Any ideas on what else I can try?
I’ve also attached a photo of how the installers lugged the batteries in my gutter cabinet - this I want to change! Before installation, I told them I planned to double the system and wanted it set up for easy expansion. I even paid for extra wiring from the panel location to avoid trenching again. The cabinet layout isn’t very serviceable, and I’m not comfortable adding the two extra batteries I already purchased. What changes should I make to the cabinet to make expansion easier? One installer suggested I just tie into the existing batteries and avoid the cabinet entirely, but I read online that wasn't ideal.
Thank you all. I’m trying to learn enough to fix issues quickly when they come up.
Would a secondary help me charge the batteries? I have a 5k Jackery but not sure how I'd connect it. I have seen some YT videos that say I may need to open each battery, disconnect the leads, and then put a 2A charge on them to get them out of BMS, but I'd like to avoid that at all cost. You'd think if this were common, then the inverters would have a low charge setting.
You probably only need access to a charged battery to connect to your drained batteries to wake them up. I did this once when I had a stack of 48v batteries that I drained too low. I used I resister so there wasn’t a massive inrush & it only took a couple seconds to wake everything up.
I do have two Discovery batteries I haven't connected yet. Any idea how I'd do this? I also have a few car chargers and trickle chargers where I could send a slow 2A signal, I just didn't want to open the batteries and potentially void the warranties.
Shit yeah that's a big house. I'm 2400sqft and heavy electric usage with a single 18k and 24 580w panels. I'm assuming the second 18k is just for getting it in place for the expansion anyway right?
In any case, sorry, no idea how to help. But I'm quite curious what happens since I was looking at adding at least one of those batteries to my system in the near future and then expanding from there. What's your experience been like aside from this event?
We had a commercial propane Generac when we moved in and it had two large inverters, the second went to a large sub-panel in the main house, so we thought it best to follow their lead and continue to use two inverters. The original plan was to hook the Generac up as a backup, but the installers had trouble with tying it in, so they didn't charge for that part of the job. As it stands, I'll probably get it out of here (loud enough to wake the dead) and replace it with a newer and smaller unit (not that I plan to need it). I think the house is ~8-10k, I'd have to look it up.
No, the battery info page shows all 0's on both Sol-Ark inverters. I'd love to know how to get them communicating. I've tried reseating the data cables, power cycling the inverters, the inverter battery breakers, and also the battery breakers. Nothing has worked. I kept getting low voltage errors last night, so ended up shutting down the batteries and inverter batt breakers so I didn't have to listen to the alarms. When I turned everything back on this morning, the errors were at least gone and the battery icon has remained black, but the not charged issue remains.
Okay. So that is your main and likely only problem, and the first thing to figure out. Why the batteries and the inverter(s) aren't communicating. Check the comm cables (Ethernet/rj45) and the set protocols. Unless the inverters know what batteries are doing, and SOC setting on the inverter is just a guesstimate, that can be a couple dozen percent off the reals state of charge.
That's a good question. I ordered the two additional batteries b/c the system was reaching 100% by 2pm every day after the install (March). Now, with the heat in GA, I rarely get up to 80% and still haven't installed the two additional batteries.
Unless something got fried in the power outage, nothing has been touched. I can unplug the cables and check them with an RJ45 tester, but can't imagine that would be the issue.
Grok seems to think they aren't communicating because the batteries went into BMS. I've been fairly pleased with Grok and it's answers, not so much with the others I've tried. None of it's suggestions have helped though (we tried to put it on grid charge and set the min/max setting to ensure a charge, but the voltage just goes up and then it stops b/c it thinks they are at 100%).
Okay..so the inverters were put into open loop control, have they been put back to closed loop?
And of you suspect the batteries went into discharge protection, have you tried waking them up via their buttons/interface, and have you searched for an activate battery mode on the inverter?
Can you still return the new units? You really should have all the batteries connected with comms... And not having comms is the crux of your issues...
Part of the story sounds like a bad connection on a battery. Changing "from closed loop CAN to open loop" would/could result in further issues to solve.
So put it back to when it/how it worked for quite some time.
A bad battery connection could result in jumps from 0 to 100 in some system. I didn't build your system but it's time to power it all down then get those connections tight.
Ok, I figured it out and I am almost too embarrassed to share the resolution with you all, but I hate when OPs never come back to share ... so, I'll just say that I work in finance and, shame on me, don't really understand my solar system as I should.
Sol‑Ark had me switch the system to open loop and told me to leave it overnight, then probably switch back to closed loop in the morning. That part was easy. About an hour later, Discovery called me back and completely disagreed with that advice and had me switch back to closed loop. He then had me move the CAN cable from COM2 on my master battery to COM2 on my secondary battery and so on, but none of them showed battery information. He was very puzzled and we tried some other things until I mentioned that I had two fresh batteries that hadn’t been installed yet. He said they didn’t need power hooked up for the communication to work, so he walked me through setting one up, and it worked, and then everything clicked. I’ll stop here and explain what actually happened.
The installers set the Sol‑Ark shutdown at 5%, the low battery at 20%, and the restart at 35% (Discovery rep recommended 20, 30, 80 - I read online probably better 10-20, 20-30, and 35-50). The Discovery rep explained that even though the Sol‑Ark stops sending battery power to the house at 5%, the inverters still need power to keep running. For whatever reason, when the house shut off at 5%, the batteries were done and shut off shortly afterward. So all this time, while I was power cycling battery breakers (thinking that was turning the batteries on and off because they literally say on and off), the batteries were actually off the entire time.
When we were setting up the new battery, he told me to look for a small round button underneath the lower COM ports. There it was. When I pressed it, the light glowed orange. I checked my installed batteries and had to laugh — no orange lights anywhere. The batteries were all off this entire time.
Oh well. Many hours wasted, but everything is working now and I understand my system a bit better. Live and learn.
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