Battery charging question

[Wildness]

I have a trailer with a dual battery setup that runs my lights and the propane heater. If put a charger on one of the batteries will it charge them both or do I need to switch to the other one?

 

[kcmusa]

if 2, 12 volt battery’s in parallel , yes that works.
if 2, 6 volt batteries in series, yes, that works If you connect to the correct terminal.

read this.

The 12volt Side of Life (Part 1)

 

[Wildness]

I assume either one can be charged to charge them both?

 

[Lou Schneider]

By "switch to the other one" do you mean there's a physical switch that lets you select one battery or the other, or both? Or just moving the charger from one battery to the other?

 

[Ex-Calif]

From a practical standpoint you will hook the charger into the DC bus where the fuses are and (assuming both batteries are connected "full time" and not switched) both batteries will charge...

 

[Gary RV_Wizard]

I assume either one can be charged to charge them both?

Refer to kcmusa's answer - it depends on the battery type (6v vs 12v) I've attached to diagrams, one for a pair of 6v batteries and one for 12v. For the 12v pair, you can connect the charger to the positive and negative of either battery and charge both. For the 6V pair, you must attach to the + terminal labeled 12v+ and the - terminal labeled Ground in the photo. The charger must be set to 12v, not 6v.

 

[Ex-Calif]

You will also notice that on the 12V parallel diagram the positive come off the first battery and the negative comes off the second battery. It is "OK" to put the charger on the positive and negative of the first battery but there is an argument that says use the positive of the first battery and the negative of the second battery for "even charging of both batteries."

It's another one of those long standing internet arguments - LOL...