Determining how many kWh my batteries should store

[CJSClimber]

I have a newly installed solar system and I am trying to figure out how many kWh of power my batteries should provide. I have 8 12v 150ah lead batteries that are connected in serial/parallel. 4 batteries are in parallel and 4 are in series. How do I determine how many kWh they should provide if they start fully charged. I don't need to know exactly, I know there are efficiency issues and whatnot, I just want to get a solid ballpark figure. Anyone have information? Thanks in advance for any help.

 

[LakeHouse]

How they're connected doesn't really matter, but 4 in parallel and 4 in series would require 16 batteries, so there's something amiss.
Ah capacity for lead-acid is dependent on discharge rate, but usually companies quote 20h drain, so the below would assume a 20h discharge:

• Ballpark estimate for absolute maximum drain (which will ruin the batteries quickly): Each battery can provide 150Ah at 12V, so 150Ah * 12V = 1800Wh. 8 batteries times 1800 Wh = 14,400Wh or 14.4 kWh
• Ballpark estimate for 50% drain (standard quoted 'usable' capacity for long-ish life): 14.4 kWh * 0.50 = 7.2 kWh

 

[crossy]

@LakeHouse is pretty much on the money.

We assume that your batteries are proper deep-cycle units and not automotive batteries.

 

[CJSClimber]

@LakeHouse is pretty much on the money.

We assume that your batteries are proper deep-cycle units and not automotive batteries.

Yes they are deep cycle

 

[CJSClimber]

How they're connected doesn't really matter, but 4 in parallel and 4 in series would require 16 batteries, so there's something amiss.
Ah capacity for lead-acid is dependent on discharge rate, but usually companies quote 20h drain, so the below would assume a 20h discharge:

• Ballpark estimate for absolute maximum drain (which will ruin the batteries quickly): Each battery can provide 150Ah at 12V, so 150Ah * 12V = 1800Wh. 8 batteries times 1800 Wh = 14,400Wh or 14.4 kWh
• Ballpark estimate for 50% drain (standard quoted 'usable' capacity for long-ish life): 14.4 kWh * 0.50 = 7.2 kWh

Thank you very much!