Deye/Sunsync failing to low voltage disconnect

[kolek]

Found the problem.
"Charge from grid" checkbox was off. Should have caught that one earlier.
Thank goodness it's not a firmware issue.

Now I'll go back and see if I can implement @timselectric clever suggestion to charge at a low voltage to offset the ongoing drop.

 

[Daddy Tanuki]

Found the problem.
"Charge from grid" checkbox was off. Should have caught that one earlier.
Thank goodness it's not a firmware issue.

Now I'll go back and see if I can implement @timselectric clever suggestion to charge at a low voltage to offset the ongoing drop.

Dude.... I am at a loss for words... thats like one of my dumbass mistakes.

 

[kolek]

Dude.... I am at a loss for words... thats like one of my dumbass mistakes.

Yeah no kidding. In my defense I'd be finding issues faster if I wasn't working with an interface from 1970.
I should be able to just plug this into my LAN and access the settings from a browser like a standard router, but Noooooooooooooooooo Deye cannot allow that, they need to be able to control and monitor your equipment and your access like something out of George Orwell's 1984.

 

[SeaGal]

Hmm. I'm a computer engineer, someone like @SeaGal who's also an engineer might have a good opinion on this as well, but there's no hardware or software reason why the inverter controls MUST be powered exclusively from battery, they could design these things to run from either, and not overdischarging the battery is mission critical. If this is normal behavior in the inverter world, then what can I say? Pretty dumb design.

IMHO it is normal as @timselectric said.

FYI my Solises also power from the DC side, PV if available or battery, if not. Not sure about the Deye/Sunsync, but my inverter has a setting for the SOC when it will stop powering AC from battery and another (lower) value which will do a force charge the battery from grid. If grid is not available, the inverter will shut down till the sun comes back up.

The quiescent draw of the Solis electronics is about 30W. However, much of that can be turned off (if you don't need to power by battery overnight) via RS485 modbus commands (and back on again in the morning) - no idea whether your inverter will do that though.

 

[LydMekk]

Yeah no kidding. In my defense I'd be finding issues faster if I wasn't working with an interface from 1970.
I should be able to just plug this into my LAN and access the settings from a browser like a standard router, but Noooooooooooooooooo Deye cannot allow that, they need to be able to control and monitor your equipment and your access like something out of George Orwell's 1984.

Install Solarman Business and you can do that. I can access my 3 both from the phone and from a browser on my PCs.
Blanket statements like that comes back and bites you in the a..

 

[Hedges]

I was told equalization should be set as low as possible to prevent equalization from happening, was told it should be deactivated for this battery type (standard EVE 280ah batteries) and 41V is as low as that setting will go.

By setting equalization voltage same as float, even if it equalizes it is just floating.
But I would set to same as boost.

Here is the discussion I had with someone in private messages:

"Equalize , the function, is only used for lead acid batteries, it will damage your lifepo4 cells, therefor it should be set to 0"

Me: "Unable to set equalization to 0. Lowest it goes is 40V."

"Depends on the firmware that your unit came with.
Setting it to 40v is fine too"

Equalization time is what should be set to zero.

Ok just got some mind-blowing information from @XO4001 via private message. He says that this is "normal" behavior for the Deye.

He says you need to set your shutdown voltage higher because even if you go below your shutdown voltage, the Deye inverter will continue pulling 50-70 watts out of the battery essentially forever, regardless of whether it's below the shutdown voltage setting, and the only way to stop it is to disconnect the battery or have your BMS step in when the voltage gets too low and shut down the battery.

INCREDIBLE if this is true. Is this normal behavior for inverters in general?

Is your inverter still producing AC, and drawing whatever wattage loads represent?
Or is 50 ~ 70W its standby draw?

My Sunny Island will consume 25W no-load, plus whatever loads demand.
In "standby" with no AC output, it draws 4W, that we can live with for a long time.

It may actually shut off at some low voltage, I've seen screen go blank.

Default operation is to shut off inverter (whether 4W or 0W I'm not sure) and 70% DoD (lead-acid), and low voltage probably triggers that regardless of actually kWh drained.

Default is to shed loads (assuming contactor wired to them) at 80% DoD, leaving inverter running and critical loads powered. That lets it restart everything on its own after charging up from PV in the morning.

If battery does get too low, Black Start requires user intervention.


Sounds like a higher voltage or SoC shutdown level is what yours needs.

 

[kolek]

Install Solarman Business and you can do that. I can access my 3 both from the phone and from a browser on my PCs.

Oh so you mean I can pay to install a 3rd party piece of proprietary crap to work around the proprietary private corporate network crap that Deye is shipping? Oh joy, what luck!

Why should I need to workaround it? I don't need to pay for a workaround to access a room full of other networked equipment that just works as it should.

Not only do you have to deal with Big Tech (or worse yet, Chinese companies like Deye) delivering crap, you have to deal with their mostly Gen Z fanboys for whom every problem is solved by installing another app on their much beloved iPhone. Dudes who've got an app for their iToothbrush which retracts its bristles and stops working if they fail to pay the monthly subscription fee.

"But it's so great! It monitors my gum health and auto-updates Instagram with pictures of my teeth."

 

[kolek]

@Hedges Hey buddy thanks for your input.
On the clever suggestion of @timselectric I've managed to solve this problem using TOU and it's been working fine.

Basically I'm just setting a minimum voltage on every time slot in TOU and marking the "Gen Charge" checkbox on each so that essentially sets a voltage floor for the battery. Not an elegant solution, but it seems to work.

 

[Daddy Tanuki]

you have to deal with their mostly Gen Z fanboys for whom every problem is solved by installing another app on their much beloved iPhone. Dudes who've got an app for their iToothbrush which retracts its bristles and stops working if they fail to pay the monthly subscription fee.

"But it's so great! It monitors my gum health and auto-updates Instagram with pictures of my teeth."

you owe me a keyboard ... cleaning out covfefe and snot costs money.