Best way to add batteries into an existing system?

[BrendanK]

Hello, all!
I am looking to add more battery storage to my garage/studio system and I'm wondering the best way to accomplish that.
I have a 6 slot server rack filled with Lifepower4 batteries and I'm going to add 3 more.
Couple questions:
Can I connect the two racks via the busbars using 2/0 gauge wire and then just loop in the 3 slot rack with a com cable as if it was the 7th 8th and 9th battery in a series?
Will I need to set my inverter to "user defined" mode until the batteries are balanced?
Thanks!

 

[DIYrich]

You can have upto 16 batteries in communication.

For best battery health, they should be wired identically.

Get a 2nd rack identical to the first (6 rack housing). Buy 2 or 4 more batteries and populate each rack with the same number of batteries. Wire each rack the same to the busbar. OK to extend comms between racks.

 

[DIYrich]

Will I need to set my inverter to "user defined" mode until the batteries are balanced?
Thanks!

Fully charge the existing batteries. Fully charge each new battery. Check voltage. If the same, then you can parallel.

 

[BrendanK]

You can have upto 16 batteries in communication.

For best battery health, they should be wired identically.

Get a 2nd rack identical to the first (6 rack housing). Buy 2 or 4 more batteries and populate each rack with the same number of batteries. Wire each rack the same to the busbar. OK to extend comms between racks.

I have one of the 3-slot racks from EG4. Assuming that would work the same?

 

[DIYrich]

I have one of the 3-slot racks from EG4. Assuming that would work the same?

Not ideal, but will work. You said you have a 6 slot rack. So you are combining a 6 slot rack with a 3 slot rack. You can adjust the length of the wire to the 3 slot rack to adjust the resistance to the battereries to be the same as the 6 slot rack.

 

[BrendanK]

Not ideal, but will work. You said you have a 6 slot rack. So you are combining a 6 slot rack with a 3 slot rack. You can adjust the length of the wire to the 3 slot rack to adjust the resistance to the battereries to be the same as the 6 slot rack.

Thanks! This is helpful and gives me a good idea of what to do