Can you use all terminals in parallel connection?

[jaycocreek]

Not much of an electrical guy myself so I thought I would ask if you can use all the terminals in a parallel connected battery..Ofcourse one positive off of one battery and one negative off the other goes to the coach or load but can the other two be used for say charging?

As shown in the picture,the two center positive and negative terminals..Can these be used for charging or say accessories?

[Gdetrailer]

Please note where iron falls with conductivity and resistivity.

From HERE

" Metal Conductivity

Conduction in metals must follow Ohm's Law, which states that the current is directly proportional to the electric field applied to the metal. The law, named after German physicist Georg Ohm, appeared in 1827 in a published paper laying out how current and voltage are measured via electrical ?circuits. The key variable in applying Ohm's Law is a metal's resistivity.

Resistivity is the opposite of electrical conductivity, evaluating how strongly a metal opposes the flow of electric current. This is commonly measured across the opposite faces of a one-meter cube of material and described as an ohm meter (O·m). Resistivity is often represented by the Greek letter rho (?).

Electrical conductivity, on the other hand, is commonly measured by siemens per meter (S·m-1) and represented by the Greek letter sigma (s). One siemens is equal to the reciprocal of one ohm. "


Click For Full-Size Image.

In the chart above, you will notice that iron falls 16 spots below Copper in conductivity..

Even Tungsten which is used in incandescent light bulbs for the filament has less resistance than iron!

So, with that chart above, you have silver, copper, gold, then aluminum as the top best conductors of electricity..

Aluminum would be a better choice for a Buss bar than iron/steel..

[Gdetrailer]

2oldman wrote:

Gdetrailer wrote:
While that can be made to work, iron and steel have a much higher resistance for the same equivalent size, thickness and length of copper.

We're only talking about a few inches of conductor.

We're only talking a few "inches" of copper also..

When one is trying to get the full potential from their 12V battery system, adding any "conductor" which has more resistance isn't really a smart way to go.

There are commercial purpose made copper buss bars available for reasonable prices, takes less work than repurposing material of lesser qualities and results in far superior performance.

Barring using a commercially made purpose built copper buss bar then simply hammering a 1/2" piece of soft copper pipe flat and drilling a couple of holes would be preferred over steel.

If neither is available then connecting multiple connections on the same battery terminal would be superior the preferred way over a steel buss bar.

Not saying it doesn't work or won't work, but heck, if one is going to the expense and hassle of setting up a power distribution system with buss bars wouldn't you like to get the maximum bang for the buck?

There IS a reason you don't find steel being used in your home and commercial wiring systems..

Auto manufacturers do cheat by using the vehicle body, but consider that there is a lot of steel involved which offsets most resistance losses.. But, there are still losses and as the vehicle ages and has been run through many winters of road salt often those remote ground connections start to fail..

[time2roll]

I went with the BlueSea 2127 with 2719 cover.

https://shop.pkys.com/Tinned-Copper-Busbars_c_45-2.html

[2oldman]

Gdetrailer wrote:
While that can be made to work, iron and steel have a much higher resistance for the same equivalent size, thickness and length of copper.

We're only talking about a few inches of conductor.

[Gdetrailer]

2oldman wrote:
Made my own from perforated L iron.

While that can be made to work, iron and steel have a much higher resistance for the same equivalent size, thickness and length of copper.

Auto manufacturers often employ multiple grounding points along the chassis and frame in order to cut costs of manufacturing since there is considerably more steel involved the resistance isn't as much of an issue but in some cases the difference in ground potential can cause noise issues like a ground loop..

1/2" copper pipe flattened out will have a lower resistance than 1/2"x1/2"x1/8" angle steel.

True story, I was in High School, the "A/V" club ran some wire 200ft from the club room stereo to the cafeteria.. One channel they used 18ga copper speaker wire, the other channel they used 16ga steel wire.. They didn't have enough money at the time to buy wire for both channels so they used some steel wire they got for free somewhere for one channel. Guess which speaker was louder (spooler alert, it wasn't the one with steel wire)..

[joebedford]

Dunno - it came with the RV. I just added an extra breaker. There are lots of items similar to this.

[2112]

You guys are too elegant. I hammered flat some 1/2" copper pipe and made some standoffs

[2oldman]

Made my own from perforated L iron.

[TechWriter]

jaycocreek wrote:
Is there a bus bar that takes those big 2 gage wires?

And then some . . . Blue Sea Bus Bars on Amazon. Remember to size the bus bar to your loads.

And then there's Victron . . .

[jaycocreek]

The biggest problem is when you put some 2 gage wires on my battery terminals,they take up a lot of the screw in terminal bolt that has non removable washers on it.

Is there a bus bar that takes those big 2 gage wires?

[LittleBill]

joebedford wrote:
This is what I have for multiple loads off the battery. The bus bar is full now - last slot used by breaker for inverter.

link to this item?

[pianotuna]

No. Balance the wiring.

[Lwiddis]

I agree with bgum. Larger bus bar.

[bgum]

The experts say you can but why not get a larger bus bar?