Good day guys. I have a quick question for the experts on here. So let me explain my situation.

We added an addition to the house and decided to upgrade the solar system aswell. We upgraded from a goodwe es 4.6 to a Deye 8Kw inverter. We took the goodwe and wired it up to the new addition of the house. The Deye inverter is run on 2 masive 4.8Kwh 48v 100Ah Lithium batteries. We baught a Small 2.4kwh Pylontech to run the goodwe for when there is loadshedding. Today i turned on a kettel and triped the Goodwe instantly because the pylontech battery is too small and it overloaded. 

Now my question is, If i buy one more Pylontech and link the 2 pylontechs in parallel for a total of 4.8Kwh and then connect them alongside the other 2 4.8Kwh lithiums, would i be able to run both inverters from the entire 14.4Kwh bank or is it not recomended to connect diffrent batteries together like that.

I know i would have to disable the Goodwes charger so that only one inverter charges the battery bank but it is not a problem as the Goodwe does not have solarpannels yet.

The only reason why i am looking to do it like this is because i am a bit out of money right now and cant afford to buy 3 more Pylontech batteries to cover the entire goodwe inverters load.

If it is posibble, how would it be done?

Thanks in advance.

Corné

Edited September 4, 20205 yr by Corne Landsberg
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9 hours ago, Corne Landsberg said:

Now my question is, If i buy one more Pylontech and link the 2 pylontechs in parallel for a total of 4.8Kwh and then connect them alongside the other 2 4.8Kwh lithiums, would i be able to run both inverters from the entire 14.4Kwh bank or is it not recomended to connect diffrent batteries together like that.

I certainly would not recommend it, without knowing anything about those two inverters.

1 hour ago, Coulomb said:

11 hours ago, Corne Landsberg said:

Now my question is, If i buy one more Pylontech and link the 2 pylontechs in parallel for a total of 4.8Kwh and then connect them alongside the other 2 4.8Kwh lithiums, would i be able to run both inverters from the entire 14.4Kwh bank or is it not recomended to connect diffrent batteries together like that.

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I certainly would not recommend it, without knowing anything about those two inverters

Okay so. The Deye inverter: 8Kw continues AC output, Surge up to 20Kw for 10 seconds. Max PV input of 10400 Watt, max 450v and 19A input. With 2 MPPT chargers.

Goodwe: 4.6kw continues output. 6200 watt PV input with the same voltage and i think 10a, also 2 mppt chargers

The Deye inverter is the same type as the Sunsync 8Kw just branded differently.

Both inverters are grid pushback capable bit the goodwe wont be pushing back because it hase no PV, and is only for backup.

Edited September 5, 20205 yr by Corne Landsberg
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3 hours ago, Coulomb said:

without knowing anything about those two inverters.

Thanks. What I meant was knowing in particular whether the battery terminals are isolated from the rest of the inverter, especially from utility which is referenced to earth. This is something the datasheets typically don't tell you.

Aaa i see. How would i go about finding this out? And what wil happen if they are not isolated.

Edited September 5, 20205 yr by Corne Landsberg

Big problem is that Pylontech are  15 cell LiFePo4 batteries , almost everyone else is 16 cell - so if your 100Ah x 2 bank is made up of 15 cells then it should be Ok if not using  CANBUS control - else I doubt it could work reliably