battery parallel or series

[Virgil Jones]

I'm working on the 12 volt solar system design.  
I have 5 100w renegy panels on roof of van (might do an additional 100w ground deploy in future).  I have 4 Trojan "Overdrive" AGM 31 batteries...180 amps each for 720 amps.  Is there any reason I should NOT put these in Parallel?

 

[B and C]

I'm working on the 12 volt solar system design.  
I have 5 100w renegy panels on roof of van (might do an additional 100w ground deploy in future).  I have 4 Trojan "Overdrive" AGM 31 batteries...180 amps each for 720 amps.  Is there any reason I should NOT put these in Parallel?

The Trojan batteries are 12v, so yes they should be wired in parallel.
You have an odd (5) number of panels so they should also be wired in parallel.

6 panels and you could have three arrays of 2 panels in series connected in parallel which together with a MPPT controller would give good charging even on cloudy days!

Nice system.  I've got battery envy.  I only have 250 amps of batteries.  I have two series strings of panels connected in parallel (400 watts total).  One string permanently mounted on roof and the other string for remote deployment over a 10GA extension cord.  I use a 30 amp Midnite Kid MPPT charge controller.