On 2023/01/11 at 10:23 AM, DeonB1003 said:

Hi Guys,

Complements of the new year to you all.

I also have the Deye 8KW hybrid inverter with 4x 5.1KWH CFE batteries, 11KWp solar. (Eskom connected, but switched off)

My question is also settings related:

During the day the batteries are usually at 100% Soc by 10h30, and immediately start to discharge to run the load. PV production stops completely 0%.

The Batteries discharge to 90% SoC and only then will the PV kick in to charge up to 100% again. Cycle repeats until the sun goes down

Is there a setting to change the discharge level to limit the discharge to 90% for instance? Time of use settings have no effect.

 

I don't mind the charge/discharge cycles, but is concerned when the batteries are on a discharge cycle when the sun goes down and I start the evening at 90% rather that 100%

 

Thanks,
Deon

 

 

 

 

Hi Deon,

I have a 8k Deye inverter with 3x 5.1kWh CFE batteries and 6kWp PV, that was installed mid December.

With no grid power, I see the batteries being charge up to 100% and then basically no solar energy being used after they hit 100% until SoC falls below 90%, at which point it starts charging back up to 100% while also supplying energy to the load. It will cycle like that while there are solar power, just like you said.

With grid power available, it actually does the same, except that the load will be fed from the solar power, so the battery discharges much slower and might seem not to drain the battery. (The off-grid case actually needed solar power on the load more than the on-grid case ...) 

As far as I can tell, it is caused by the  BMS of the CFE batteries. Basically trying to get away from sitting at 100% SoC the whole day. In theory that should improve the longevity of the batteries over the long run.

The question now is why CFE feels the need to do that while other battery manufacturers don't...

 

This brings me to the total lack of control the (8k?) Deye inverter has over solar charging.

If there are settings I missed, I will be very grateful to be enlightened 

The 8k Deye basically always charge the batteries to 100% SoC, all the time (solar > load). You can change "time of use" or any other settings as much as you like, you will not be able to stop it from doing that (bar unplugging the solar panels). This was probably a good strategy back in the lead-acid days, but lithium batteries need more control, as they actually do not like sitting at 100% the whole day.

What I would like to do is to charge the batteries up to 100% early in the morning (The BMS needs this to calibrate the SoC and balance the cells)

Then I would like to be able to let it use only battery power untill SoC reaches 75%, at which point it should feed solar power to the load and charge the battery when it falls below 75%.

This can't be done with a Deye as far as I know. I would be interested to hear if other inverters can do this, or indeed if I am (hopefully) missing something.

I can achieve what I just described when I disconnect the solar panels and only use grid charge, but the moment I connect the solar, it ignores all settings and cook the batteries all the way up to 100% ...

My load is about 300W, so solar > load almost always.

I probably stand alone in wanting to maximize the longevity of my batteries instead of maximizing the energy they store.

 

 

Edited January 12, 20233 yr by sjp

This should be easily achievable by ticking the "time of use" (deye calls it that I believe) or "use timer" (sunsynk) setting and setting the battery % to what you want to cycle it to

Edited January 13, 20233 yr by abd7

2 hours ago, abd7 said:

This should be easily achievable by ticking the "time of use" (deye calls it that I believe) or "use timer" (sunsynk) setting and setting the battery % to what you want to cycle it to

No

The percentage specified in each time slot is the minimum % wanted. If PV is present it will charge all the way up to 100%. If Grid Charge is ticked and battery percentage drops below SOC% for that time slot then Grid is used to charge it back up to specified %

Ah didn't read the question fully 

Have a question on the deye inverter as well.  having some solar panels connected trough micro inverter directly into my house ac power supply.  Will the deye inverter able to manage the surplus on the ac house supply ?  giving it back to grid/charging the battery ?

34 minutes ago, Pietje said:

Have a question on the deye inverter as well.  having some solar panels connected trough micro inverter directly into my house ac power supply.  Will the deye inverter able to manage the surplus on the ac house supply ?  giving it back to grid/charging the battery ?

Any reason you are going through a micro-inverter as opposed to plugging the panels directly into the deye?

57 minutes ago, Pietje said:

Have a question on the deye inverter as well.  having some solar panels connected trough micro inverter directly into my house ac power supply.  Will the deye inverter able to manage the surplus on the ac house supply ?  giving it back to grid/charging the battery ?

The Deye has a micro-inverter input option on the AUX/Smartload port, for additional solar  input. It might be simpler just to run the panels on a string into the Deye's PV inputs.

3 hours ago, mzezman said:

Any reason you are going through a micro-inverter as opposed to plugging the panels directly into the deye?

its already my existing solar panel setup which i cant wire to deye inverter

Edited January 15, 20233 yr by Pietje

I am curious why you guys keep it so complicated. Personally I intend to set grid charge 24/7 to ensure the batteries are at 65%... that is my load shedding buffer and it will always be restored when there is Eskom power (this means I don't have to predict when exactly we have Eskom power as we face potential stage 8 load shedding or worse). I have 2x 5kwh batteries with 90% DOD and 6000 cycles, but only 2700watt of solar panels. So if there is poor sunshine for a few days, i'll always be using Eskom and have 65% for load shedding.

Edited May 7, 20233 yr by whateversa

On 2023/05/07 at 5:59 PM, whateversa said:

I am curious why you guys keep it so complicated. Personally I intend to set grid charge 24/7 to ensure the batteries are at 65%... that is my load shedding buffer and it will always be restored when there is Eskom power (this means I don't have to predict when exactly we have Eskom power as we face potential stage 8 load shedding or worse). I have 2x 5kwh batteries with 90% DOD and 6000 cycles, but only 2700watt of solar panels. So if there is poor sunshine for a few days, i'll always be using Eskom and have 65% for load shedding.

...Because you can be utilising the battery instead of Eskom at night, so you can save costs and not waste solar power. The batteries\solar enable you in essence, to store power for later use. using battries during the day (or as you put it 100% down to 65% during the day is unnecessary)

My system was installed 2years ago, all was fine until now. The Deye 8kw inverter is stuck in a reset cycle. The screen resets and go into the system settings menu, then resets again. This cycle repeats continuously within 5 seconds, thus no time to check errors or change settings. Disconnecting DC, AC, load, grid and switching battery off makes no difference. When it gets power from any source, it falls into this cycle within a few seconds.

Any advice on where to service/repair the inverter would be appreciated. 

 

 

Is everything still running normally? My screen died and I had to replace the screen, but on the app I could see the inverter was still working correctly. They send a new screen to my installer and he replaced the screen complete with replacement warranty stickers.

No, sometimes the main screen comes on for a split second, and it shows "off". Also no power when switching off grid. Its clear that it cant startup.