Do batteries charge when plugged in to shore power?

[shilohako]

I am new to motorhomes and to my 76 brave.  I am getting ready for winter and was wondering if the batteries are charged when it is plugged into shore power, or do I need a trickle charger on them?

[Oz]

When you plug into shore power, your battery isolator shuts off power to the batteries as the converter converts the 120v to 12v for your coach to use.

That system wasn't changed until years later.  So, the only way shore power will charge your batteries is if you get a newer, "smart" charge wizard.

Yes, you would need a trickle charger.

[shilohako]

ok my next question is how to connect all batteries to charger or do I need multiple chargers?

[Oz]

Your coach batteries are connected together and then are connected to battery solenoid (isolator).
Your chassis battery is connected to the isolator by itself.
The isolator controls the charging back to the batteries when the engine is running.
So, you would either need two chargers, or you can disconnect the chassis battery and connect it to one of the coach batteries and use one charger.

Personally, I never did the latter because you have to remrmber to reconnect the chassis battery to run the engine, which you should every couple weeks or so during off-season.

But, if you don't plan on running it at all, you could do it that way.

[DaveVA78Chieftain]

That system wasn't changed until years later.  So, the only way shore power will charge your batteries is if you get a newer, "smart" charge wizard.

Not necessarily true.  By 76 Winnebago was using 30 amp or 50 amp Progressive Dynamics Power Centers that included a built in battery charger that charged the Coach battery while supplying 12VDC to the rig when plugged into shore power.  The bad part with these Power Centers is they could over charge the coach batteries and boil the water out of them.  In the late 80's, the smart charger converter eliminated that problem.

The 69-75 rigs used a standalone converter (PD694) that may or may not have a coach battery charger (option dependent).

[Oz]

Well, I guess it all depends if you have a smart charger or not.  I did the best I can, but I'm not an electrical whiz. At least I'm trying to answer questions.

[77Brave]

Isn't it always best to disconnect and charge each battery individually?

[Oz]

Well, when the RV is charging the coach batteries, they're charged together at the same time.

[TerryH]

Isn't it always best to disconnect and charge each battery individually?

If you are using an external, stand alone charger, yes. Always disconnect the negative first, then positive and reconnect in reverse. If you are relying on the originally installed charger which is incorporated with your converter, and no unusual modifications have been made you should be fine. Regardless, and especially as you likely do not have a factory installed three stage charger, regularly check the fluid level of each battery. A boil over situation can be dangerous as well as a potential fire hazard.