So I decided to get a little crazy with some extra power in my trunk. I thought I had everything covered and then someone made a very good comment on how to properly parallel batteries. Im not going to bother to try and explain it but the picture I attached should be clear enough. The example in the picture is for a 120VDC system but the principle is the same.

 

if it was a good comment what was it, and if your point is a good one why not state what the heck it is... dont expect that image to answer any questions as it only raises questions
Why would ANYONE post a 120VDC system picture and expect to detract meaning from it in a 12 volt world


how could any wiring change the internal resistance of a battery? the wiring could change the systems resistance... it could do any one of a number of things but it wont change the internal resistance

 

This is a good tip when you are wiring for the amps too.

 

it doesn't lower the subs impedance it lowers the SYSTEM impedance.

 

the difference between the two illustrations is minimal in fact only one wire is physically located differently and electrically they are identical

I am not saying you are wrong as I am not following your point (though you have not actually said what the difference is so I am asking, why one is better than another). I have seen several wire their systems exotic batteries kind of odd... and I am certain if wired incorrectly one battery will do more work than the others even when in parallel. Personally I would always use bus bars and I would tap power for the amp in the middle of the bank (which I think is the point of all this).

 

This depends a lot on the cable thickness, a 0.2V difference on charging would make a substantial charge difference on the top rows.

 

I agree to a point, the battery layout should have equal lengths of copper from each battery to a common positive buss bar (and the corresponding - buss bar) and as many of the batteries close to the load (amplifier) and alternator/ charging point. The original image on this thread is a 120VAC system that has little to do with our hobby.

 

But it has to do!

I did a simple drawing, it is the same, but with only 2x 12V bats