Not a fan of that, see the discussion in Incrementally Adding AC Batteries, same basic problem that current sources will bite you without a master controller.,,,the best way to add a 3rd party battery/inverter to Ensemble to power a completely off-grid setup.
I saw that. If the consumption is always more than the microinverter output or the inverter is big enough like Jack's with an empty or battery with head-space it'll work, but the edge cases always get you (e.g., full battery). I still think MID (microgrid interconnection device) inverters will be generally available before too long, or the IQ8s. But, #274 still seems like the most economically viable solution at this point.Jack Rickard was using a similar technique to power his shop before Ensemble came along.
AC Coupling is only the reliable solution I know of for that....The main goal is to hack the system into not requiring the grid to initialize. ...
The AC coupling solutions always seem to need to be big to control the microinverter current reversals; Outback talks about some of the engineering challenges in their app note....It wouldn’t necessarily need a lot of kWh....
The "no export" idea is interesting, I haven't heard of anyone doing that and I've no clue how well it might work as no export "tries" to keep the export to zero...but transients do get through....Ensemble can be set to self consumption or whatever use case optimizes the system...
Thanks for your thoughts. This was mainly a thought experiment for me. Am currently getting set to submit a system design to Enphase for approval. Its an interesting process.AC Coupling is only the reliable solution I know of for that.
The AC coupling solutions always seem to need to be big to control the microinverter current reversals; Outback talks about some of the engineering challenges in their app note.
The "no export" idea is interesting, I haven't heard of anyone doing that and I've no clue how well it might work as no export "tries" to keep the export to zero...but transients do get through.
|Date/Time||Energy Produced (Wh)||Energy Consumed (Wh)||Exported to Grid (Wh)||Imported from Grid (Wh)||Stored in AC Batteries (Wh)||Discharged from AC Batteries (Wh)|
It does charge from solar during the day if below the reserve, you can see that in the graph above. Seems to usually work just fine. You could be right though; when I explained to the Enphase tech why I had it set that way I could hear his eyeballs crossing over into double-vision. He said he hadn't heard of it before but there was no reason it shouldn't work.... it can't charge any time the sun is shining. Could that be confusing the logic?
That's what was happening from noon to two p.m. for sure, but not the drop at 2 AM. I buy that's a mis-report/stuck queue since the batteries suddenly show 5 kwh gone, but from the graph above you can see it didn't get consumed by the house or get exported to the grid... it was just gone without discharging (it's the basis for my theory above).Is it possible it was pulling power from one battery and pushing it into one of the others to even out the state of charge?
I asked about that, they said when it does a SoCMaintenance you can see it drop... but 50% of the battery power is way beyond abnormal for that. He also said the system doesn't need to be set to 100% to do a cell balance, it's supposed to do it once a day. Sorta sounds like an active balancer, which after watching Will's videos makes me wonder (of course, could just be Will keeps getting crap active balancers; he does have an amazing tendency to get broken stuff).Maybe the system also does a cycle like that once in a while as a test of the batteries?
It might be worth running a capacity test on all four units separately. They can't be easily isolated and I'll have to wait until I don't need the Air Conditioning, one unit can't run it. Something for this winter.Run one battery low, check it's performance, then use power from another battery to charge it back up, and test the next battery that was run low.
It's really more than 3.3 kWh per unit (I suspect 4 to 5), they limit it so it has the power for the warranted period. Since each unit is an AC battery (defined as a dc battery + Inverter + charger for those unfamiliar with the term) they all run independently and the SoC in one could go to 10% while another is at 100%, but that would be horrid management of course. The "brain" should be looking at the shunt SoC and getting them to share equally. In my previous tests it worked flawlessly (e.g., at the end of the test all units had the same SoC).Have you taken the cover off and looked inside one of the Encharge battery units? I think the spec says that each 3.3 KWH is using a stack of 4 iQ8 inverters, but I am curious if they all are running in parallel, or does each one have a number of cell connected?
Taking the cover off is okay, but you have to do some disassembly for the rest, and that voids the warranty so haven't gone there.How many cells are they running in series? Since it is based on a solar panel inverter, I would expect it to be around a 40 volt system. Is there a separate BMS module in there, or does each iQ8 have extra wires to monitor a few cells? How hard would it be to extend out some wires to externally monitor all of the cell voltages?
That's the first thing I learned, you can never have enough diagnostics. At least you can whip out the meter for a double-check when you need to. But yeah, being able to get remote diagnostics and log them is priceless. Love my RTL-SDR when it doesn't hang or windows decides to reset the comm port. Hopefully, the upcoming W11 won't be a nightmare.... I already miss not having the blue tooth....
|This was interesting. I switched the battery profile to full backup this morning, figure|
based on the data from the 12th (#294) might be "healthier" to let it run that way
for a few days and watch the logs.
The batteries are still set to only charge from solar, but I expected them to charge
from excess solar (which it's cloudy and I don't have currently).
Instead, it's what you see to the right. The batteries are charging from solar, but the
house is consuming grid, that is it's not waiting for excess solar to charge the
batteries which seems like a flaw.
I'm pretty sure the ability to manually switch battery charging from solar to grid is
new, previously the system decided for you.
Previously when StormGuard came on it charged the battery from the grid. That's
what I want it to do, a lot of times we don't get much warning so you want rapid
charging. Curious if that will automatically switch.
Each inverter consumes around 60mW during the night and an Encharge 3 battery will consume around 20W to maintain SoC(State of Charge) when it is idle.
"Mon Sep 27, 2021 08:17 AM EDT" "EnchargeSoCMaintenance : Clear" "Mon Sep 27, 2021 08:08 AM EDT" "EnchargeAGFPropagationDone" "Mon Sep 27, 2021 08:08 AM EDT" "EnsembleModGone : Clear" "Mon Sep 27, 2021 08:05 AM EDT" "Device is excluded from the aggregate SOC: Clear" "Mon Sep 27, 2021 08:04 AM EDT" "EnchargeOnGrid" "Mon Sep 27, 2021 08:04 AM EDT" "EnchargeZigbeeCommFailure : Clear" "Mon Sep 27, 2021 08:03 AM EDT" "EnchargeSwitchedToPrivateKey" "Mon Sep 27, 2021 07:48 AM EDT" "EnchargeZigbeeModuleError" "Mon Sep 27, 2021 07:48 AM EDT" "EnchargeSwitchedToGlobalKey" "Mon Sep 27, 2021 07:48 AM EDT" "EnchargeGridTied" "Mon Sep 27, 2021 07:48 AM EDT" "EnchargeLostCommsWithGWSwitchTOGridTied" "Mon Sep 27, 2021 06:48 AM EDT" "EnchargeZigbeeModuleError" "Mon Sep 27, 2021 06:48 AM EDT" "EnchargeZigbeeCommFailure : Set" "Mon Sep 27, 2021 06:59 AM EDT" "Device is excluded from the aggregate SOC: Set" "Mon Sep 27, 2021 06:58 AM EDT" "EnsembleModGone : Set" "Sun Sep 26, 2021 09:14 AM EDT" "EnchargeSoCMaintenance : Set"