Paralleling two LiFePo4 48v batteries to an 18Kpv

[caesarv]

I have my Gobel DIY battery box with MB30 cells (304Ah) supplying my 18Kpv inverter. All is working flawlessly but I want to double my storage capacity as the battery pretty much drains each night now that winter is approaching. I have ordered a duplicate battery box, but with MB31 cells (314Ah) because they no longer stock the MB30 cells. The current battery is connected to the inverter via 3ft 2/0 cables. Each battery box has two positive terminals and two negative terminals.
I have two choices:
1. I can run independent cables from the new battery to the inverter's second set of battery input terminals (costlier and messier.)
2. I can run short cables (about 1 ft) from the new battery to the second set of terminals on the first battery which would then go to the inverter via the existing 2/0 cables (cleaner and cheaper.)
The most amperage that each battery will see (both in and out) is about 100A.
If I do use the second method, would it matter which battery (304 vs 314Ah) is first in the chain?
Both batteries have a Pace PC200 BMS and a 4A active balancer. Both have a beefy 250A circuit breaker, but there are no fuses.
Opinions welcome.

 

[DIYrich]

Near the battery, put in a busbar.
Main wires to/from the inverter attach to the busbar.
Use equal length wires to connect batteries to the busbar.

Do you batteries charge to near 100% every day? If not, adding batteries won't help with being drained at night.

 

[caesarv]

Thanks, but I would prefer not adding a busbar.
If it is sunny, I can easily charge to 100% each day and still have a couple of hours of sunlight left. If not, then I don't mind recharging via the grid during off-peak hours.

 

[caesarv]

After some research, I guess I will answer my own question. A great explanation is here.
In my case, since there are only two batteries, the website states: "Finally, if you only have 2 batteries, then simply linking them together and taking the main feeds from diagonally opposite corners cannot be improved upon." This is more obvious if you look at 'Method 2' on that webpage.