Deye/Sunsync failing to low voltage disconnect

[kolek]

Battery shutdown is set to 50V. AFAIK, that is the low voltage disconnect setting.
The Deye knows the battery voltage is below 50V, it's reading the battery voltage as 49.2V.
But it's been drawing 0.5A out of the battery for the last 4-5 hours since it hit 50V, leading to the battery to fall to 49.16V.
Went to sleep at 3AM when it hit 50V, at that time it was slowly transitioning from battery to grid and it had reduced drain on the battery to almost nothing. I figured, "Ok, the inverter has only 1 job to do at this point, it will be fine." Wrong.
Woke up to these readings. It never stopped draining the battery even after transitioning below 50V.
Since the Deye cannot seem to figure out it needs to stop draining the battery, I manually have disconnected the battery until I can sort this out.
This is the first time this system has needed to perform a low voltage disconnect, it was connected to the grid for the first time yesterday.
Anyone know what is going on here?

 

[kolek]

In advance I'm going to request no off topic posts please. If you see a setting you don't agree with, if it has nothing to do with the problem, please refrain. Thank you. Really need to focus on solving this because I cannot even keep my battery connected to the inverter until this problem is fixed.

 

[Lt.Dan]

Set your equalization voltage to 55.2v maybe? It's the only value below the 50v, so maybe it is attempting to reach that value?

Not sure without seeing more settings.

 

[kolek]

Set your equalization voltage to 55.2v maybe? It's the only value below the 50v, so maybe it is attempting to reach that value?

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.

 

[Lt.Dan]

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.

If the equalization time is set to 0 hours, then it will not equalize. It's the only thing that jumps out at me right away. Takes a few minutes to try.

 

[kolek]

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"

 

[kolek]

Takes a few minutes to try.

Ok I will check.

 

[Lt.Dan]

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"

I will say again, and you can refer to your manual if you want.

If the equalization time is set to 0 hours. It will not initialize an equalization cycle.

You already have it set to 0 hours, so no matter what you set the equalization voltage to, it WONT START THE CYCLE.

if you dont want help, dont ask.

 

[kolek]

Changed the setting to 54V, now it matches the settings here of @XO4001
This screenprint shows the settings of @XO4001
He also has equalization time set to 0 hours, that is the default.

 

[kolek]

If the equalization time is set to 0 hours. It will not initialize an equalization cycle.

Researching what to set this value to. If you have an opinion as to what it should be set to, feel free to offer it.

 

[kolek]

Tested with equalization voltage set to 54V, switched battery back on, it's still draining the battery, no change. Checked the Deye manual for "equalization time," nothing in the text about it. Searching now for an appropriate value. The manual shows a picture with a value of 2 hours, may try that.

Edit: Testing now with 2 hours.

 

[kolek]

Set equalization voltage to 54V and equalization time to 2 hours, switched battery back on and it's still draining the battery.

My Google foo is failing me, what is equalization time exactly? Is it the transition time the inverter takes to switch from battery to grid and vice-versa?

You already have it set to 0 hours, so no matter what you set the equalization voltage to, it WONT START THE CYCLE.

So even if I switch to 2 hours and 54V, basically it's too late this time around for the correct settings to work, it needs to be set before the transition takes place for it to work properly?

 

[marionw]

You did not mention, or I missed it, are you operating in closed or open loop with the batteries?

 

[kolek]

Searching... found @MisterSandals, he also agrees with the person who private messaged me, saying:
"First off, lithium batteries should not be equalized. Easiest to set equalization time to 0."

finally bought solar

Thanks for this nice and informative reply...i have 6pcs 455w panels and 8pcs lf280k cells and jk 200a bms...in future i will expand my sistem but for now this only goes to part of my house... balancing the battery is my priority for now before i start to assemble everything

diysolarforum.com

 

[kolek]

You did not mention, or I missed it, are you operating in closed or open loop with the batteries?

I don't have comms. I have the pieces to get communication set up between a Victron Smart Shunt and my inverter, but haven't had a chance to implement that yet.

 

[kolek]

Still searching equalization, found:
@BentleyJ says "Battery equilzation is for Lead Acid Chemistry ONLY."
and his comment is upvoted by @Wet1 @timselectric and @TomC4306
So that's 6 people now who say don't equalize LiFePO

Equalizing bank of eg4 batteries

I have been using a bank of 6 eg4 lifepower batts for about 50 days now and have had the equalization settings on the lv6548 inverters in the default setting which is disabled for all equalization. the charging for today is done and the SOC s are varied from 93.4 up to 100.4 percent SOC across...

diysolarforum.com

 

[Daddy Tanuki]

Still searching equalization, found:
@BentleyJ says "Battery equilzation is for Lead Acid Chemistry ONLY."
and his comment is upvoted by @Wet1 @timselectric and @TomC4306
So that's 6 people now who say don't equalize LiFePO

Equalizing bank of eg4 batteries

I have been using a bank of 6 eg4 lifepower batts for about 50 days now and have had the equalization settings on the lv6548 inverters in the default setting which is disabled for all equalization. the charging for today is done and the SOC s are varied from 93.4 up to 100.4 percent SOC across...

diysolarforum.com

if you set equalization at the same or lower than your bulk or float settings it will do nothing more than the bulk or float settings. so if you normally set your bulk charge rate at 54.4, then set your equalization at 54.4 and then set it for one minute. what will happen (if your gear responds to its own settigns properly) is that as soon as you hit the traget of 54.4, it will enter equalization for 1 minute at 54.4 volts. in other words it does nothing but add 1 minute of charge at 54.4 to yoru batteries.. no issues

equalization was originally an additional charge period at a higher (much higher) rate to stirr up and mix the electrolyte in the cells to get them to internally equalize out and to help keep sulfates form forming on the lead plates.

as this is not needed in a Lithium battery, simply set it to the same voltage as your normal charge settings and give it one minute of setting.

if it force you to set it at a higher rate then your bulk settings then set it a .1 volt higher. IE: 54.4 is bulk and equalization is 54.5 for one minute. once again it will not harm anything as its not high enough nor long enough.

 

[kolek]

@Daddy Tanuki Good morning my friend and fellow gaijin in Japan. Hope you are doing well. Thanks for your input.

 

[kolek]

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?

 

[Daddy Tanuki]

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, 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. Do other inverters have this problem?

FWIW, a magnum will do the same thing, but at a much lower rate. the inverter itself will shutdown, but the BMK module (battery shunt) and the display both continue to draw power as a very, very low rate but it will eventually drain you down to a very very low state of charge.