Battery disconnect switch

Will the battery charge no matter the switch position... IT DEPENDS.

Most RVs without a big inverter are wired more or less like this

Battery---Fuse or breaker---Switch---Fuse panel and other breakers---Stuff
(Stuff is water pump furnace, Lights, Slides, and all the other "Stuff" that runs on 12 volts)

Some however are

Converter or Converter/Inverter-Fuse--Switch--Battery---Fuse--Panel--Stuff

Now the key word in both setups is SWITCH. That's the battery disconnect

How to tell how your RV is wired.

Step one.. With battery connected and RV unplugged turn on 12 volt light inside RV (Most any light will do) Now disconnecct. LIght goes off .. GOOD.. Re-connect and PLUG IN

Again disconnect. LIght goes off.. Battery and converter are on same side of switch and battery will charge

Light stays on.. Battery will NOT charge use a battery tender if you want charging when not connected

MrWizard wrote:
the answer, as above, No .. yes

BUT WHY ?

do you have super duper batteries that won't self discharge ?
do you have flawless 120vac that will never fail ?
if the batteries are disconnected, and the power fails. the fridge will turn off
it will NOT even switch to LP, because unless you have a very old camper
the fridge has controls that use 12v
and if you do have a very old camper and fridge, then everything is manual not automatic
same thing for your heater/furnace, you need 12v

the only time my batteries get disconnected is during service

never disconnect batteries while using the RV
you can disconnect while in storage

I don't have a smart converter/charger so I always disconnect the batteries, when stored or when connected to shore power. Don't want the batteries to overcharge and boil. Certainly if AC fails I'm out of luck but it's not something I worry about. Just me, depends on where you're parked.

darsben1 wrote:
But unless there is a separate wire from the converter to the battery the circuit is not complete and NO BATTERY CHARGING CAN TAKE PLACE. It is an open circuit.
The OP could run a separate ground wire from the converter to the negative post of the battery and then charging would take place.
Lights would run off the converter but I would not try to run slides or other heavy draw items.

A separate wire from the converter is no different then having batteries connected. All you've done is eliminate the disconnect switch.

the answer, as above, No .. yes

BUT WHY ?

do you have super duper batteries that won't self discharge ?
do you have flawless 120vac that will never fail ?
if the batteries are disconnected, and the power fails. the fridge will turn off
it will NOT even switch to LP, because unless you have a very old camper
the fridge has controls that use 12v
and if you do have a very old camper and fridge, then everything is manual not automatic
same thing for your heater/furnace, you need 12v

the only time my batteries get disconnected is during service

never disconnect batteries while using the RV
you can disconnect while in storage

Hi,

The converter powers the 12 volt side of my RV with the battery disconnected.

NO, YES. You could always try it and see.

The battery disconnect should completely isolate the battery. However, it is good practice to have the battery connected when plugged into 120. It is my understanding that the 12 volt systen can see large voltage swings if the battery is disconnected. (When operating a slide, for example.)

But unless there is a separate wire from the converter to the battery the circuit is not complete and NO BATTERY CHARGING CAN TAKE PLACE. It is an open circuit.
The OP could run a separate ground wire from the converter to the negative post of the battery and then charging would take place.
Lights would run off the converter but I would not try to run slides or other heavy draw items.

When my battery is switched off, the converter ( when on shore power ) runs all my 12v things.

Usually, the converter will power the system- the battery disconnect only disconnects the battery from the system.