Wiring coach batteries in a series or parallel

[mikekaidan]

Sent: 5/10/2007

Hope you all had a nice winter... spring is here and summer around the corner, time to "Get 'er ready"   Searched, but couldn't find the answer.

What is the proper way to wire two, or more batteries on the same circuit. In case I'm not making myself clear,  I have one Chassis battery, and two Coach batteries. Coach batteries are both 12V Deep cycle.

First battery has ground and positive, how do I tie the second battery in w/o creating 24V? Simply link the posts? I've had the batteries out all winter, but last year, one battery was always dead, I'm not convinced they were ever installed properly...

I know somebody will have an answer... you guys always do!

Thanks,

Mike,

Proud owner of Rinky Dink-1980 Brave

[Lefty]

Sent: 5/10/2007

Link the batteries up by hooking the positive to one, to the positive to the other, and then do the same for the negative. This will give you 12v.

[Slantsixness]

Sent: 5/10/2007

In order to NOT develop 24V,

The batteries MUST be PARALLELED,

NOT in SERIES!

Parallel increases capacity, but only when both batteries are in optimal condition.
(Paralleling 2 batteries when either one or both are in poor condition, will defeat the parallel arrangement: the batteries will simply try to charge each other... (a vicious cycle resulting in even LOWER output capacity))

Series connections are voltage additive. And unless you have a 24V diesel pusher, you'll blow your lightbulbs and your converter/charger out, and overheat or damage a lot of electical equipment.

Parallel connections:
connect the "+" terminal on Battery 1 to the "+" terminal on Battery 2
connect the "-" terminal on Battery 1 to the "-" terminal on Battery 2

The "-" terminal on both batteries goes to ground
Both "-" terminals MUST EACH GO TO Chassis GROUND, even if only one wire is used.

Either "+" terminal can be used for the 12V supply.

I will not describe "series" connections here, unless you are using 6 volt batteries or your diesel pusher runs off 24v, there would be no need for series connections.

[Oz]

Sent: 5/10/2007

It's just that easy. (+) to (+), (-) to (-).   The other way (opposing terminals) is used when connecting two 6v batteries together to create a 12v charge, like they were in the Chariot.  This is popular when using batteries from an electric fork lift.  They are big and heavy, but they are designed to hold a charge, under heavy load, for a long time. 

- Sob

[mikekaidan]

Sent: 5/11/2007

Thanks guys, it makes sense, and forgive me for using the term "series" vs. "parallel" but that was my concern, creating 12v vs. 24v.

If I understand this correctly then, when set up parallel, BOTH batteries are only has good as the weakest due to them charging one anther right?

So has far as charging them while driving (duel switch on) I take it both batteries should also charge equally, correct?

Not sure what happened  last summer, but as it turned out, I think I was only running one of the two batteries. (Possible bad connection.. who knows) when I removed them, one was OK, the other was totally dead (but has seemed to recharge in my garage) which tells me they weren't parallel because one should have charged the other, leaving me w/ two equall charged/discharged batteries... right?

Anyway, thanks for the help, I'll get them in this weekend, along w/ some serious cleaning, oil change and ready for some fun!!