Connecting Eco-worthy rack batteries with two EG4 Inside Wall Mount batteries

[unw1red]

I have searched and read and searched for an answer to my question with no luck.

I have five Eco-worthy rack batteries in parallel. I have two EG4 Inside Wall Mount batteries in parallel. I know I can connect the two dissimilar stacks via busbars and cables, but I have another method that begs asking.

The connectors on top of the EG4 batteries are basically a busbar, can I not connect the Eco-worthy stack to the connectors on the EG4 like it was another battery in parallel? The amperage would be 500 vs 280. The voltage is 48V, of course. The wattage would be 25.5kWh instead of 14.3kWh.

Is it feasible? Is it safe?

 

[wpns]

Yes, you can buy the 'Degson' connectors and make up your own cables to connect to the 600A busbars in the WallMount batteries, just make sure your overcurrent house is in order.

 

[unw1red]

Yes, you can buy the 'Degson' connectors and make up your own cables to connect to the 600A busbars in the WallMount batteries, just make sure your overcurrent house is in order.

I appreciate the feedback

 

[joechan33]

Yes, you can buy the 'Degson' connectors and make up your own cables to connect to the 600A busbars in the WallMount batteries, just make sure your overcurrent house is in order.

Hi wpns, what is overcurrent house is in order?

 

[wpns]

Hi wpns, what is overcurrent house is in order?

Just make sure that the EW and the EG4 batteries can’t run more than 600A through the EG4 built-in busbar

 

[marionw]

The issue may be, what is the current/power rating for the EG4 Wall Mount battery bus bars.
The spec sheet says they are rated at 600 amps. But also what is the amperage rating of each cable that connects each battery.

Each battery bus bar and battery cable will carry the current of the batteries "behind" it so the current increases with each battery inline starting with the one furthest from the inverter (negative cable). The negative cable from the battery closest to the inverter will carry the whole load.
You also need to consider a possible catastrophic failure.

From the Battery Manual.
Systems with more batteries than these configurations require the use of an external fused positive
busbar and an unfused negative busbar rated at a minimum of 200A per battery. Each fuse should
be a maximum of 250A. Alternatively, larger systems could rely on the 18kPV’s ability to draw from
different battery packs while still paralleling inverters rather than utilizing external busbars.

The maximum recommended number of paralleled 18kPV inverters is 6. If this approach is used, we
recommend a ratio of 2 batteries per pack controlled by each 18kPV inverter. Separating packs is
only recommended if each pack's average SOC is monitored over time and does not diverge by
more than 10%. Common busbars are superior to separating battery packs but it may be difficult to
source fused positive busbars rated to greater than 1800 Amps.
This translates into separating packs larger than 9 batteries. Refer to NEC code and the local AHJ for exact requirements.