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Which lead should I connect my charger for 2 12V batteries wired Parallel?

wired1

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Hi Folks,

My question is should I use the same + and - battery posts that I have wired my Inverter from or the opposite posts, or does it even matter? Same question for the inverter, does it matter if I connect the inverter to the + and - of the same battery or to one post from each battery?

I have 2x200 AH LiFePO4 Ampere Hour batteries and a Progressive Dynamics 12V 45-Amp Battery Charger and a 12V Renogy 1000 Watt inverter.
 
for two batteries in parallel, either connect to a busbar with equal wires and connect charger/inverter/etc. to there (a "Y" connection),
Or connect in parallel with equal cables and connect other things to diagonally opposite posts.

The idea is for each battery to see identical series resistance to the load/charger.
 
I put a bus bar between my inverter, batteries, and Solar Charge Controllers. This is how the Battery is wired:

1625332421741.png
I had two 8 post, 3/8" Stud busbars, one for the positive and one for the negative. This is how things are hooked to the busbar:
1625332521307.png
On the picture above, there is an eighth stud that is empty for expansion.

I went through great care to make sure the wires connecting the batteries were of the same length, but once it left the battery to the busbar, they are of different lengths. The positive cable is 12 inches from the busbar, and the negative cable is 36 " from the busbar. The inverter had a little difference, but not that extreme.
 
Diagonal, also called cross corner. Charge and discharge resistance will be equal, so should current to/from batteries. Another advantage is the two wires between battery terminals run at half current each. So a 6 AWG system only needs 2ea 8 AWG between terminals. Did I mention, the two need to be same length and type? Easy enough to buy in pairs.
 
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I put a bus bar between my inverter, batteries, and Solar Charge Controllers. This is how the Battery is wired:

View attachment 54904
I had two 8 post, 3/8" Stud busbars, one for the positive and one for the negative. This is how things are hooked to the busbar:
View attachment 54906
On the picture above, there is an eighth stud that is empty for expansion.

I went through great care to make sure the wires connecting the batteries were of the same length, but once it left the battery to the busbar, they are of different lengths. The positive cable is 12 inches from the busbar, and the negative cable is 36 " from the busbar. The inverter had a little difference, but not that extreme.
So, it it very important for the wires to be exact length. I will be going from my + battery post to a 150 amp breaker, then to the + of the inverter with #1 AWG. The negative will go direct to the inverter, same size wire. I will wire my 45 amp charger either direct to the opposite + and - of the 2 batteries with 6 AWG or perhaps to a buss bar first, then to the batteries. Just wondering also how/ where to wire my hall effect charge/discharge monitor. Is it ok for that to see the charging amperage, meaning can I wire that to the same buss bar, or direct to the batteries. Or am I overthinking this??? Does any of that matter
 
I don’t know what a Hall effect discharge monitor is but my shunt is the first item off the negative terminal of the battery before the busbar.
o, it it very important for the wires to be exact length. I will be going from my + battery post to a 150 amp breaker, then to the + of the inverter with #1 AWG.
It is very important that all wires from the different batteries are the same length until they are joined but after that does not matter.

In my earlier picture, The bottom left red positive wire is 4/0 and goes from the battery to a bus bar about 12 inches away, but took about two and a half feet of wire to make the connection because of obstacles and an ANL fuse. The top right wire is also 4/0 and goes to a bus bar 3 feet away, but because of obstacles and adding a shunt, the length was 4 feet.

When making battery cables joining my batteries to 2s2p configuration, I took great care to make them the same length.

Matching resistance between batteries or cells is extremely important, but not when it leaves the battery to go to a device or busbar.

————-
On a different issue, I think 1 gauge is too small, but if your loads are small could be fine. I have 4/0 for a 2000 watt inverter.
 
I don’t know what a Hall effect discharge monitor is but my shunt is the first item off the negative terminal of the battery before the busbar.

It is very important that all wires from the different batteries are the same length until they are joined but after that does not matter.

In my earlier picture, The bottom left red positive wire is 4/0 and goes from the battery to a bus bar about 12 inches away, but took about two and a half feet of wire to make the connection because of obstacles and an ANL fuse. The top right wire is also 4/0 and goes to a bus bar 3 feet away, but because of obstacles and adding a shunt, the length was 4 feet.

When making battery cables joining my batteries to 2s2p configuration, I took great care to make them the same length.

Matching resistance between batteries or cells is extremely important, but not when it leaves the battery to go to a device or busbar.

————-
On a different issue, I think 1 gauge is too small, but if your loads are small could be fine. I have 4/0 for a 2000 watt inverter.
Hi Chrisski,
I just re-read this post and wondered if you could send a picture of your wiring?
 
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