# Connecting batteries in parallel - some questions: - Page 4

Posted by Jim on January 9, 2010, 11:22 am

It seems to me that electrically they are identical.  Am I wrong here?

On Fri, 1 Jan 2010 16:37:27 -0600, "Daniel who wants to know"

Posted by vaughn on January 9, 2010, 2:49 pm

Post top or bottom as you wish.  But since we can't read your mind, at least
give us a bit of context so we know what "they" you are thinking about.  Then
perhaps we can give you a meaningful answer.

Vaughn

Posted by Daniel who wants to know on January 11, 2010, 2:40 am

Yes and no, all 3 schemes are electrically identical in that the batteries
are in parallel but only star or "cross" as I call it allows for an equal
length and thus resistance path through the cabling to each battery.  When
connected as a string the battery closest to the source or load will hog
almost all of the current due to the resistance of the cabling between each
battery.  When star connected with equal lengths (and gauges) of cable the
current will be shared equally, similarly with "cross" if you draw a line
from the main positive to the main negative through each battery 1 at a time
you will see that the cabling length is equal no matter which you go
through.

Posted by Jim on January 12, 2010, 1:48 am

Thanks Daniel, that's the way I will wire it, Cross.
I plan to pick up another identical deep cycle in the
next few days, install the seconc panel now sitting in the garage
awaiting warmer weather, and add on panels/batteries as the finances
permit.  It would probably pay to have extra jumpers made
up at this time, all identical for future use.  Thanks
again for the information.

Jim

On Sun, 10 Jan 2010 20:40:30 -0600, "Daniel who wants to know"

Posted by Josepi on January 13, 2010, 5:17 pm

Think of every connection as a small resistor and every inch of wire as a
resistor and then do the math.

Thanks Daniel, that's the way I will wire it, Cross.
I plan to pick up another identical deep cycle in the
next few days, install the seconc panel now sitting in the garage
awaiting warmer weather, and add on panels/batteries as the finances
permit.  It would probably pay to have extra jumpers made
up at this time, all identical for future use.  Thanks
again for the information.

Jim

On Sun, 10 Jan 2010 20:40:30 -0600, "Daniel who wants to know"