Hey everyone,

New here and SUPER new to solar. My system was installed this past Thursday, 2 days ago.

I want to set my inverter to charge the battery at night from grid when it drops below a certain %.

From reading here and from the manual, it seems simple enough.

I have the Deye 8K hybrid.

When I go to System Work Mode setting, it is only in volts, and I see no way to switch it to %.

I am sure it is something simple I am missing somewhere.

Please help?!

Share screen shot of your battery settings page. What batteries are you running with this 8kW Beast?

The battery is 1 x 14.3Kw MD Solar Lithium.

Screenshots attached.

In the manual though, it shows both V and %:

It is that 2nd screen with Batt % that I am after, but for the life of me, cannot find it.

Too use % you must select “Use Batt %” in the battery settings page. This is not really ideal for lithium batteries though. It’s better to select “Lithium” so the BMS in the battery can communicate it’s SOC and other settings to the inverter. This requires CAN comms cable between the battery and the inverter but I’m not sure if your installer has done that. 
 

The way you have it set now is workable. Some actually prefer using voltage control. Roughly speaking, 49v is 0%, 54v is 100%, 51.5v is 50%. You need to take voltage sag into account and the voltage vs SOC curve is not actually linear. It needs a bit of thought.

Letting the battery BMS handle this is the safest and all the battery SOC settings will show as %. Check with your installer why they haven’t done it this way. 

Edited November 26, 20223 yr by BrettB

7 hours ago, BrettB said:

Too use % you must select “Use Batt %” in the battery settings page. This is not really ideal for lithium batteries though. It’s better to select “Lithium” so the BMS in the battery can communicate it’s SOC and other settings to the inverter. This requires CAN comms cable between the battery and the inverter but I’m not sure if your installer has done that. 
 

The way you have it set now is workable. Some actually prefer using voltage control. Roughly speaking, 49v is 0%, 54v is 100%, 51.5v is 50%. You need to take voltage sag into account and the voltage vs SOC curve is not actually linear. It needs a bit of thought.

Letting the battery BMS handle this is the safest and all the battery SOC settings will show as %. Check with your installer why they haven’t done it this way. 

 

Thank you SO much for that Brett! Can't believed I did not spot that.

It 100% is Lithium, and the CAN comms cable IS installed. I changed it to Lithium and yes, immediately the work mode changed to %.

Now I have something else weird ...

I set the 1st option from 19:00 to 05:00 to use grid charge. It is now 07:12 and it is charging from grid. Should it not completely stop using the grid at 05:00?

To be fair, the battery is very low at 5%. PV is 914W and load is 670W, so I would think grid is not needed at all at this point? Could it just be because the battery is SO low?

Even now at 7:25, it is still drawing from the grid, even though there is more than enough coming in on PV:

This is from Solar Assistant.

This is the work mode timer setup:

 

@Richeloafter you changed your settings to Lithium, there is one more check to see that the inverter & battery are communicating. It's this page, you must see these type of numbers....if you see on the 1st & 2nd line a set of 0000 then you still don't have Comms. 

You access this screen by clicking on the battery icon on the work flow home page. Then click bottom right corner to see this. 

Make sure that your Solar MD is setup with CAN & option zero. Via this page in the battery settings page. Please ignore my settings I have shown here it is for a different battery. You must hav CAN & option 0 for the Solar MD. 

 

My installers clearly messed up! 🤬

They WILL be phoned tomorrow to come fix their install!

Because the comms is not working properly right now, should I just use % instead of lithium until it is fixed?

Let's maybe try on here to fix this if you patient enough. Send pics of the BMS cable from the battery & the port in which it is plugged into. Otherwise I will understand if you rather get the installer to assist tomorrow, I would not use % value until that Solar MD is sending reliable % SoC info to the inverter. Otherwise the inverter is guessing. In that case voltages are best used & I can help you with that. 

17 minutes ago, Steve87 said:

Let's maybe try on here to fix this if you patient enough. Send pics of the BMS cable from the battery & the port in which it is plugged into. Otherwise I will understand if you rather get the installer to assist tomorrow, I would not use % value until that Solar MD is sending reliable % SoC info to the inverter. Otherwise the inverter is guessing. In that case voltages are best used & I can help you with that. 

Thank you so much for your amazing support Steve.

My knowledge and experience with these things can only be classified as dangerous 🤪

I'm going to wait for the installer who got paid a LOT of money to do this right, to come and fix their setup 😉

SO ... Spoke to my installer today.

He says the CANBUS on the battery IS connected to the BMS port on the inverter, but he claims that without the MD Solar logger, it won't show any data on the inverter like you posted @Steve87.

Do you have the Solar MD data logger, or is he BS'ing me?

He says that without the logger, using V is MUCH more accurate, as you stated as well.

Is there some rough table that shows the corresponding battery % in Volts, in 10% increments? I know it won't be 100%, just a rough idea so I can set the mode to V, and the work time in V based on the percentage I want?

Edited November 28, 20223 yr by Richelo

Does this look about right for the 48V?

Also this one.

I'll stop now 🤪

Hi Richelo, 

Previously, the SolarMD battery would only "talk" to Sunsynk via the Solar MD data logger.

There has been an update to the BMS firmware for the SolarMD battery, that allows direct communication with Sunsynk/Deye and Victron (NO data logger required). 

Ask you installer to contact SolarMD directly to confirm.

Edited November 28, 20223 yr by Chunks
Sunsynk and Deye should be the same protocol