Charging 4 batteries with external charger.

I assume that you have your batteries hooked up to provide 12 volts to your coach. If you hook up the charger at the same point where the 12 volt output is taken from, there should be no problem at all.

To keep everything happy and confusion at a minimum connect the charger to the same posts that the feeds to the coach are connected along with positive of the charger to the positive of the coach,,,

Short answer: yes. But only a little.

These would be arranged 2 each in series, to make two pairs in parallel. Best practice would be to attach charger positive to the end terminal on one pair and the negative to the end terminal on the other pair.

I do this often to keep my 4 six volt batteries in good shape.

First of all, set your charger on the 12 volt charging option (most chargers have six and twelve volt options or if digital will sense the proper voltage setting).

Next connect the positive charger cable to the positive battery terminal which is connected to the 300 amp fuse leading to the inverter. This is the positive cable that enters the interior of the motorhome.

Then connect the negative charger cable to the negative terminal in the battery bank which is connected to the cable that enters the coach and establishes the ground connection for the battery bank.

Make sure you use a good 3 stage charger for the operation and realize that it may take up to 2 days to fully charge your battery bank.

supercub wrote:
My RV has 4, 6 volt batteries. I've recently run them down and need to charge them with an external charger.

Think we could talk you through how to post pictures? A picture of your batteries and a picture of your charger would allow the smart guys to give you better advice.

You will actually charge better if you charge 2 at a time.

A solar system would have prevented this.

supercub wrote:
My RV has 4, 6 volt batteries. I've recently run them down and need to charge them with an external charger. Does it matter which positive post your connect the positive cable to and which negative post you connect the negative wire to?

Batteries need to be wired in a balanced manner for them to charge.

Look at method #3 at the smartgauge site.

This is what is balanced and best for twin twelve volt batteries.



As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

Does it matter which positive and negative.. yes and no.

Now.. with six volt pairs you have

-{6v}+-{6v}+
-{6v}+-{6v}+

and in thie diagram you can connect a standared 12 volt charger to either LEFT negative and either RIGHT positive

Do not connecte to the ones in the middle.

I have to ask since no one else has.

How many amps is your external battery charger?

I'm using a 10 amp charger.