Battery Connections

[butkus51_]

I run two RV batteries on my 5er. I want my lights to run twice as long. Is the proper connection + to + and - to -? I have been told some applicatios are + to - on both posts of the batteries. Is my wiring correct because my 5er lights do not seem to run twice as long.

[time2roll]

Timay wrote:
Please help me understand how putting the plus and minus on opposite sides will make the first battery get a better (more equal) charge...seems to me that IT DOESN'T MATTER. Electricity runs at the speed of light and putting the plus and minus anywhere on the line that feeds both batteries will accomplish the same charge.

Of course, this is more than my opinion - if it matters I am a master electrician.

Tim

pianotuna wrote:
How to connect multiple 12 volt batteries

[Timay]

enblethen wrote:
Downtheroad:
That is correct!
That will give a closer to equal charge and discharge.

Please help me understand how putting the plus and minus on opposite sides will make the first battery get a better (more equal) charge...seems to me that IT DOESN'T MATTER. Electricity runs at the speed of light and putting the plus and minus anywhere on the line that feeds both batteries will accomplish the same charge.

Of course, this is more than my opinion - if it matters I am a master electrician.

Tim

[Water-Bug]

enblethen wrote:
Downtheroad's post is almost correct, however, it is better to have positive and negative off opposite ends of the 12 volt system. The first battery in the drawing will get the best charge.
Of course this is only my opinion!

The condition of the batteries and guage of the wire will make a bigger difference than which battery is connected closest to the charger. The resistance of the wire between the batteries is almost unmeasurable. If two lights are turned on, does the one closest to the battery glow brighter ? The same laws of physics apply to both charging and discharging.

EDIT: If the batteries were 50 feet apart and connected with a light guage wire, the connection sequence might make a difference, but at 2 or 3 feet apart and connected with the proper guage wire there is no measurable difference.

[davidaf]

How are you determining you aren't getting more time out of your lights? If you boondock LED will be money well spent if lighting is your primary draw.

[time2roll]

Are you charging the batteries fully at 14.4 to 14.8 volts?
To really extend the time you have lights on consider some LED lamps.

[SailingOn]

12 Volt Side of Life

[MerkelG]

Try the 12volt side of life . Com

[2oldman]

If all you run is lights, then you can increase your time from 2 weeks to 4.

[RoyB]

You may be running into a new battery added to an old battery situation. We have found both batteries should be the same capacity and age as much as possible. An older battery will drag down a new battery to its capacity - not the other way around.

The same holds true when charging two different batteries at the same time. They both will charge differently if different types of batteries...

Roy Ken

[enblethen]

Downtheroad:
That is correct!
That will give a closer to equal charge and discharge.

[downtheroad]

enblethen wrote:
Downtheroad's post is almost correct, however, it is better to have positive and negative off opposite ends of the 12 volt system. The first battery in the drawing will get the best charge.
Of course this is only my opinion!

You are correct...How about this.

[enblethen]

Downtheroad's post is almost correct, however, it is better to have positive and negative off opposite ends of the 12 volt system. The first battery in the drawing will get the best charge.
Of course this is only my opinion!

[downtheroad]

[jims1]

If the are 12volt batteries then you want positive to positive, neg to neg. You also want to put the positive cable from the trailer to the positive on one battery, and the negative from the trailer on the other batteries negative post.