aux charger for coach batt

[HD rver]

I would like to hookup an aux charger to my coach batts (2 12vs) and I was wondering if I hooked the pos lead to the pos pole on 1 batt and the neg lead to the neg pole on the 2nd batt. Any info would be appreciated. I've been hooked to shkore for about 2 weeks and the coach batts are down to about 8 volts. Thks, Chuck & Cissy

[RJay]

Your coach should be connected to the battery bank that way. Just connect the charger to the same terminals that the coach leads are connected. Your individual batteries will be charged equally as a bank.

[HD rver]

Thks RJay, I thought it would be that way, but also was wondering if the normal hookups would need be to disconnected while using the aug charger. Thks

[Wizard]

Almost everything I have ever read about charging batteris suggest disconnecting all loads. Depends on the charger that you use. Some older, cheaper chargers could damage some 12v appliances and modern engine controls. Most newer better quality chargers is not a problem.
I personally, never disconnect anything, just attach the leads then turn the charger on. Never had a problem.

[RJay]

Keep in mind, if you use anything in the coach that requires DC power, it increases the time to charge the bank. Depending on the size of the charger and the size of the load it's possible to discharge your batteries even though you are charging them.

[wa8yxm]

If you are asking if that will work.. YES. However a few questions:

You said "Positive to one and negative to the other" Paraphrased slightly)

I can see four ways to interpret that

1: Your coach (Starting) batteries are the problem and you have two 12 volt in parallel.

If so that will work Just fine. No problems.. You could also hook both leads to the proper post on the same battery and it would also work.

2: Your house batteries are the problem and you have a pair of six volt
If so that is the only way to do it, WHY because there are not six volt batteries in RV's. just 2 piece 12 volt batteries, you use the positive on one and negative on the other, remaining posts are jumpered, making the two halves into one whole 12 volt battery. (This is a very simply way of thinking about six volt pairs)

3: The two batteries you mention are 1: House and 2: Coach (or the other way around) in which case ONLY the battery you attach the positive wire to will charge. (Well you did say COACH batteries needed it)

4: You have multiple 12 volt HOUSE batteries in parallel, Same as condition 1.

But in all 4 cases, It will work. So long as you put the positive lead on the battery that needs a charge.

Now, if your coach is not charging the chassis (Coach/starting) batteries but *IS* charging the house batteries... Google Trick-l-Start

[John Hilley]

Quote:

Originally Posted by HD rver I would like to hookup an aux charger to my coach batts (2 12vs) and I was wondering if I hooked the pos lead to the pos pole on 1 batt and the neg lead to the neg pole on the 2nd batt. Any info would be appreciated. I've been hooked to shkore for about 2 weeks and the coach batts are down to about 8 volts. Thks, Chuck & Cissy

You say you were on shore power for two weeks. If your converter works, you should be fully charged. Since you said you were down to 8 volts, it sounds like they are boiled dry and are probably ruined. Check the water level before charging.

[HD rver]

Thks guys I have 4, 12 v batts that puts out 12 v. The house batts seem to be charging just fine, but chassis batts were down. I'm using a batt tender and it is bringing the batts back up. I just wondering if the chassis batts are suppose to charge when using shore power. Thks, Chuck

[wa8yxm]

It depends HD.. Some rigs do have what are called Bi Directional isolator systems, with this system the engine charges house batteries when running and the house returns the favor when you are running generator or on shore power.

Some coaches only have one way isolators where the engine charges the house, when running but ..... The favor is not returned.

Without knowing your rig... Impossible to say which it is (Post make model and year)

Of course the Trick-l-start (As I said before, Google Trick-l-start) adds the "Return of favor" shall we say

Or just leave your battery tender hooked up all the time.