Hello, 

I have 2 DEYE hybride inverters and 12 batteries 51v et 5 kWh. I want to put the inverters in parallelI and i need use all my batteries, but the manufacturer specifies that a maximum of 8 batteries can be placed in series or in parallel. 

To use all the batteries I plan to make two packs of 6 batteries in parallel and connect each pack to an inverter (see schematic in attached).

Can someone tell me if i can connect the batteries as in the attached diagram. won't there be communication problems because the inverters are in parallel

I thank you for your help.

Schéma de principe.pdf

The maximum parallel count is more a battery function than an Inverter thing,the more batteries you stack the more oddities can occur between them

We've got Pylontech locally that can do 8/16 depending on generation without a Hub,and up to 40 batteries with a BMS hub managing everything

Hello PsyWulf,

Tank you for your reply. I already have 12 batteries so I'm not going to change them. I am looking for a solution to use them all.

it is for this reason that I ask if I can connect the batteries as in the diagram?

 

6 minutes ago, Pierre-loiret said:

it is for this reason that I ask if I can connect the batteries as in the diagram?

Noted,however as I explained what the inverter manufacturer says is of little consequence,but it should work theoretically,though you could have a bit of an oddity with unbalanced loads ( PV/AC ) causing differing discharges and edge cases like one set hitting its cutoff voltage before the other (in a worst case scenario) or overloading your grid input trying to grid charge both sets if you don't limit the Amps to each inverter charging

thanks you, 

if there is no risk other than the imbalance of charging and discharging the batteries, I will test this connection. I will connect 6 batteries on each inverter.

4 hours ago, Pierre-loiret said:

Hello, 

I have 2 DEYE hybride inverters and 12 batteries 51v et 5 kWh. I want to put the inverters in parallelI and i need use all my batteries, but the manufacturer specifies that a maximum of 8 batteries can be placed in series or in parallel. 

To use all the batteries I plan to make two packs of 6 batteries in parallel and connect each pack to an inverter (see schematic in attached).

Can someone tell me if i can connect the batteries as in the attached diagram. won't there be communication problems because the inverters are in parallel

I thank you for your help.

Schéma de principe.pdf 64.8 kB · 3 downloads

If the Deye/Sunsynk power sharing is based on the same strategy as axperts and many others, then the common battery bus becomes the sharing  vehicle.  It is also the sharing vehicle for even distribution of pv power. So its a prerequisite. 

For two inverters to share the load, they must both have an equal share of dc input power. That is entertained by a common battery bus. 

Even if one pv string is delivering more power than the other, they are still equally shared, because the strong string will deliver 'charge' power on battery bus, which in turn will be consumed as discharge power on the inverter with less pv power. 

So individual battery busses makes no sense. 

Further to this, how can a manufacturer of inverter be concerned about how many batteries are parralelled? , as the inverter will not know of this, other than higher charge current that will be required, but  the limit to that can easily be set on the inverter.  Unless the inverter gets confused about bms metrics of multiple packs, which is bad functionality. 

 

EDIT: so a parralelling config virtualizes the system into 'one' inverter, 'one' battery and 'one' pv source. Otherwise it serves a hopeless purpose. 

Edited December 23, 20223 yr by BritishRacingGreen

Thank you, 

it is the battery manufacturer who limits the number of batteries in series or in parallel to 8.

1 minute ago, Pierre-loiret said:

Thank you, 

it is the battery manufacturer who limits the number of batteries in series or in parallel to 8.

I see, that is a pity. 

9 minutes ago, Pierre-loiret said:

Thank you, 

it is the battery manufacturer who limits the number of batteries in series or in parallel to 8.

That makes sense as with the pylontech example,over a certain number the manufacturer won't offer support/warranty for issues unless they are managed by an approved method

Finally, can I put a battery pack of 6 batteries on each inverter as on the attached plan.
if so, would there be any disruption in BMS communication?